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Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder most commonly involving the occipital scalp and posterior neck characterized by the development of keloidlike papules, pustules, and plaques. If left untreated, this condition may progress to scarring alopecia. It primarily affects males of African descent, but it also may occur in females and in other ethnic groups. Although the exact underlying pathogenesis is unclear, close haircuts and chronic mechanical irritation to the posterior neck and scalp are known inciting factors. For this reason, AKN disproportionately affects active-duty military servicemembers who are held to strict grooming standards. The US Military maintains these grooming standards to ensure uniformity, self-discipline, and serviceability in operational settings.1 Regulations dictate short tapered hair, particularly on the back of the neck, which can require weekly to biweekly haircuts to maintain.1-5
First-line treatment of AKN is prevention by avoiding short haircuts and other forms of mechanical irritation.1,6,7 However, there are considerable barriers to this strategy within the military due to uniform regulations as well as personal appearance and grooming standards. Early identification and treatment are of utmost importance in managing AKN in the military population to ensure reduction of morbidity, prevention of late-stage disease, and continued fitness for duty. This article reviews the clinical features, epidemiology, and treatments available for management of AKN, with a special focus on the active-duty military population.
Clinical Features and Epidemiology
Acne keloidalis nuchae is a chronic inflammatory disorder characterized by the development of keloidlike papules, pustules, and plaques on the posterior neck and occipital scalp.6 Also known as folliculitis keloidalis nuchae, AKN is seen primarily in men of African descent, though cases also have been reported in females and in a few other ethnic groups.6,7 In black males, the AKN prevalence worldwide ranges from 0.5% to 13.6%. The male to female ratio is 20 to 1.7 Although the exact cause is unknown, AKN appears to develop from chronic irritation and inflammation following localized skin injury and/or trauma. Chronic irritation from close-shaved haircuts, tight-fitting shirt collars, caps, and helmets have all been implicated as considerable risk factors.6-8
Symptoms generally develop hours to days following a close haircut and begin with the early formation of inflamed irritated papules and notable erythema.6,7 These papules may become secondarily infected and develop into pustules and/or abscesses, especially in cases in which the affected individual continues to have the hair shaved. Continued use of shared razors increases the risk for secondary infection and also raises the concern for transmission of blood-borne pathogens, as AKN lesions are quick to bleed with minor trauma.7
Over time, chronic inflammation and continued trauma of the AKN papules leads to widespread fibrosis and scar formation, as the papules coalesce into larger plaques and nodules. If left untreated, these later stages of disease can progress to chronic scarring alopecia.6
Prevention
In the general population, first-line therapy of AKN is preventative. The goal is to break the cycle of chronic inflammation, thereby preventing the development of additional lesions and subsequent scarring.7 Patients should be encouraged to avoid frequent haircuts, close shaves, hats, helmets, and tight shirt collars.6-8
A 2017 cross-sectional study by Adotama et al9 investigated recognition and management of AKN in predominantly black barbershops in an urban setting. Fifty barbers from barbershops in Oklahoma City, Oklahoma, were enrolled and interviewed for the study. Of these barbers, only 44% (22/50) were able to properly identify AKN from a photograph. Although the vast majority (94% [47/50]) were aware that razor use would aggravate the condition, only 46% (23/50) reported avoidance of cutting hair for clients with active AKN.9 This study, while limited by its small sample size, showed that many barbers may be unaware of AKN and therefore unknowingly contribute to the disease process by performing haircuts on actively inflamed scalps. For this reason, it is important to educate patients about their condition and strongly recommend lifestyle and hairstyle modifications in the management of their disease.
Acne keloidalis nuchae that is severe enough to interfere with the proper use and wear of military equipment (eg, Kevlar helmets) or maintenance of regulation grooming standards does not meet military admission standards.10,11 However, mild undiagnosed cases may be overlooked during entrance physical examinations, while many servicemembers develop AKN after entering the military.10 For these individuals, long-term avoidance of haircuts is not a realistic or obtainable therapeutic option.
Treatment
Topical Therapy
Early mild to moderate cases of AKN—papules less than 3 mm, no nodules present—may be treated with potent topical steroids. Studies have shown 2-week alternating cycles of high-potency topical steroids (2 weeks of twice-daily application followed by 2 weeks without application) for 8 to 12 weeks to be effective in reducing AKN lesions.8,12 Topical clindamycin also may be added and has demonstrated efficacy particularly when pustules are present.7,8
Intralesional Steroids
For moderate cases of AKN—papules more than 3 mm, plaques, and nodules—intralesional steroid injections may be considered. Triamcinolone may be used at a dose of 5 to 40 mg/mL administered at 4-week intervals.7 More concentrated doses will produce faster responses but also carry the known risk of side effects such as hypopigmentation in darker-skinned individuals and skin atrophy.
Systemic Therapy
Systemic therapy with oral antibiotics may be warranted as an adjunct to mild to moderate cases of AKN or in cases with clear evidence of secondary infection. Long-term tetracycline antibiotics, such as minocycline and doxycycline, may be used concurrently with topical and/or intralesional steroids.6,7 Their antibacterial and anti-inflammatory effects are useful in controlling secondary infections and reducing overall chronic inflammation.
When selecting an appropriate antibiotic for long-term use in active-duty military patients, it is important to consider their effects on duty status. Doxycycline is preferred for active-duty servicemembers because it is not duty limiting or medically disqualifying.10,13-15 However, minocycline, is restricted for use in aviators and aircrew members due to the risk for central nervous system side effects, which may include light-headedness, dizziness, and vertigo.
UV Light Therapy
UV radiation has known anti-inflammatory, immunosuppressive, and antifibrotic effects and commonly is used in the treatment of many dermatologic conditions.16 Within the last decade, targeted UVB (tUVB) radiation has shown promise as an effective alternative therapy for AKN. In 2014, Okoye et al16 conducted a prospective, randomized, split-scalp study in 11 patients with AKN. Each patient underwent treatment with a tUVB device (with peaks at 303 and 313 nm) to a randomly selected side of the scalp 3 times weekly for 16 weeks. Significant reductions in lesion count were seen on the treated side after 8 (P=.03) and 16 weeks (P=.04), with no change noted on the control side. Aside from objective lesion counts, patients completed questionnaires (n=6) regarding their treatment outcomes. Notably, 83.3% (5/6) reported marked improvement in their condition. Aside from mild transient burning and erythema of the treated area, no serious side effects were reported.16
Targeted UVB phototherapy has limited utility in an operational setting due to accessibility and operational tempo. Phototherapy units typically are available only at commands in close proximity to large medical treatment facilities. Further, the vast majority of servicemembers have duty hours that are not amenable to multiple treatment sessions per week for several months. For servicemembers in administrative roles or serving in garrison or shore billets, tUVB or narrowband UV phototherapy may be viable treatment options.
Laser Therapy
Various lasers have been used to treat AKN, including the CO2 laser, pulsed dye laser, 810-nm diode laser, and 1064-nm Nd:YAG laser.6 Kantor et al17 utilized a CO2 laser with a focused beam for surgical excision of a late-stage AKN case as early as 1986. In these patients, it was demonstrated that focused CO2 laser could be used to remove fibrotic lesions in an outpatient setting with only local anesthesia. Although only 8 patients were treated in this report, no relapses occurred.17
CO2 laser evaporation using the unfocused beam setting with 130 to 150 J/cm2 has been less successful, with relapses reported in multiple cases.6 Dragoni et al18 attempted treatment with a 595-nm pulsed dye laser with 6.5-J/cm2 fluence and 0.5-millisecond pulse but faced similar results, with lesions returning within 1 month.
There have been numerous reports of clinical improvement of AKN with the use of the 1064-nm Nd:YAG laser.6,19 Esmat et al19 treated 16 patients with a fluence of 35 to 45 J/cm2 and pulse duration of 10 to 30 milliseconds adjusted to skin type and hair thickness. An overall 82% reduction in lesion count was observed after 5 treatment sessions. Biopsies following the treatment course demonstrated a significant reduction in papule and plaque count (P=.001 and P=.011, respectively), and no clinical recurrences were noted at 12 months posttreatment.19 Similarly, Woo et al20 conducted a single-blinded, randomized, controlled trial to assess the efficacy of the Nd:YAG laser in combination with topical corticosteroid therapy vs topical corticosteroid monotherapy. Of the 20 patients treated, there was a statistically significant improvement in patients with papule-only AKN who received the laser and topical combination treatment (P=.031).20
Laser therapy may be an available treatment option for military servicemembers stationed within close proximity to military treatment facilities, with the Nd:YAG laser typically having the widest availability. Although laser therapy may be effective in early stages of disease, servicemembers would have to be amenable to limitation of future hair growth in the treated areas.
Surgical Excision
Surgical excision may be considered for large, extensive, disfiguring, and/or refractory lesions. Excision is a safe and effective method to remove tender, inflamed, keloidlike masses. Techniques for excision include electrosurgical excision with secondary intention healing, excision of a horizontal ellipse involving the posterior hairline with either primary closure or secondary intention healing, and use of a semilunar tissue expander prior to excision and closure.6 Regardless of the technique, it is important to ensure that affected tissue is excised at a depth that includes the base of the hair follicles to prevent recurrence.21
Final Thoughts
Acne keloidalis nuchae is a chronic inflammatory disease that causes considerable morbidity and can lead to chronic infection, alopecia, and disfigurement of the occipital scalp and posterior neck. Although easily preventable through the avoidance of mechanical trauma, irritation, and frequent short haircuts, the active-duty military population is restricted in their preventive measures due to current grooming and uniform standards. In this population, early identification and treatment are necessary to manage the disease to reduce patient morbidity and ensure continued operational and medical readiness. Topical and intralesional steroids may be used in mild to moderate cases. Topical and/or systemic antibiotics may be added to the treatment regimen in cases of secondary bacterial infection. For more severe refractory cases, laser therapy or complete surgical excision may be warranted.
- Weiss AN, Arballo OM, Miletta NR, et al. Military grooming standards and their impact on skin diseases of the head and neck. Cutis. 2018;102:328, 331-333.
- US Department of the Army. Wear and Appearance of Army Uniforms and Insignia: Army Regulation 670-1. Washington, DC: Department of the Army; 2017. https://history.army.mil/html/forcestruc/docs/AR670-1.pdf. Accessed April 14, 2020.
- U.S. Headquarters Marine Corps. Marine Corps Uniform Regulations: Marine Corps Order 1020.34H. Quantico, VA: United States Marine Corps, 2018. https://www.marines.mil/portals/1/Publications/MCO%201020.34H%20v2.pdf?ver=2018-06-26-094038-137. Accessed April 14, 2020.
- Grooming standards. In: US Department of the Navy. United States Navy Uniform Regulations: NAVPERS 15665I. https://www.public.navy.mil/bupers-npc/support/uniforms/uniformregulations/chapter2/Pages/2201PersonalAppearance.aspx. Updated May 2019. Accessed April 14, 2020.
- Department of the Air Force. AFT 36-2903, Dress and Personal Appearance of Air Force Personnel. Washington, DC: Department of the Air Force, 2019. https://static.e-publishing.af.mil/production/1/af_a1/publication/afi36-2903/afi36-2903.pdf. Accessed April 14, 2020.
- Maranda EL, Simmons BJ, Nguyen AH, et al. Treatment of acne keloidalis nuchae: a systemic review of the literature. Dermatol Ther (Heidelb). 2016;6:362-378.
- Ogunbiyi A. Acne keloidalis nuchae: prevalence, impact, and management challenges. Clin Cosmet Investig Dermatol. 2016;9:483-489.
- Alexis A, Heath CR, Halder RM. Folliculitis keloidalis nuchae and pseudofolliculitis barbae: are prevention and effective treatment within reach? Dermatol Clin. 2014;32:183-191.
- Adotama P, Tinker D, Mitchell K, et al. Barber knowledge and recommendations regarding pseudofolliculitis barbae and acne keloidalis nuchae in an urban setting. JAMA Dermatol. 2017;12:1325.
- Burke KR, Larrymore DC, Cho S. Treatment considerations for US military members with sin disease. Cutis. 2019;6:329-332.
- Medical standards for Appointment, Enlistment, or Induction Into the Military Services (DoD Instruction 6130.03). Washington, DC: Department of Defense; May 6, 2018. https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/613003p.pdf. Accessed April 27, 2020.
- Callender VD, Young CM, Haverstock CL, et al. An open label study of clobetasol propionate 0.05% and betamethasone valerate 0.12% foams in treatment of mild to moderate acne keloidalis. Cutis. 2005;75:317-321.
- US Department of the Army. Standards of medical fitness. https://www.qmo.amedd.army.mil/diabetes/AR40_5012011.pdf. Published December 14, 2007. Accessed April 27, 2020.
- US Department of the Air Force. Medical examinations and standards. https://static.e-publishing.af.mil/production/1/af_sg/publication/afi48-123/afi48-123.pdf. Published November 5, 2013. Accessed April 27, 2020.
- US Navy Aeromedical Reference and Waiver Guide. https://www.med.navy.mil/sites/nmotc/nami/arwg/Documents/WaiverGuide/Complete_Waiver_Guide.pdf. Published September 4, 2019. Accessed April 14, 2020.
- Okoye GA, Rainer BM, Leung SG, et al. Improving acne keloidalis nuchae with targeted ultraviolet B treatment: a prospective, randomized split-scalp study. Br J Dermatol. 2014;17:1156-1163.
- Kantor GR, Ratz JL, Wheeland RG. Treatment of acne keloidalis nuchae with carbon dioxide laser. J Am Acad Dermatol. 1986;14(2, pt 1):263-267.
- 18. Dragoni F, Bassi A, Cannarozzo G, et al. Successful treatment of acne keloidalis nuchae resistant to conventional therapy with 1064-nm Nd:YAG laser. G Ital Dermatol Venereol. 2013;148:231-232.
- Esmat SM, Hay RMA, Zeid OMA, et al. The efficacy of laser assisted hair removal in the treatment of acne keloidalis nuchae; a pilot study. Eur J Dermatol. 2012;22:645-650.
- Woo DK, Treyger G, Henderson M, et al. Prospective controlled trial for the treatment of acne keloidalis nuchae with a long-pulsed neodymium-doped yttrium-aluminum-garnet laser. J Cutan Med Surg. 2018;22:236-238.
- Beckett N, Lawson C, Cohen G. Electrosurgical excision of acne keloidalis nuchae with secondary intention healing. J Clin Aesthet Dermatol. 2011;4:36-39.
Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder most commonly involving the occipital scalp and posterior neck characterized by the development of keloidlike papules, pustules, and plaques. If left untreated, this condition may progress to scarring alopecia. It primarily affects males of African descent, but it also may occur in females and in other ethnic groups. Although the exact underlying pathogenesis is unclear, close haircuts and chronic mechanical irritation to the posterior neck and scalp are known inciting factors. For this reason, AKN disproportionately affects active-duty military servicemembers who are held to strict grooming standards. The US Military maintains these grooming standards to ensure uniformity, self-discipline, and serviceability in operational settings.1 Regulations dictate short tapered hair, particularly on the back of the neck, which can require weekly to biweekly haircuts to maintain.1-5
First-line treatment of AKN is prevention by avoiding short haircuts and other forms of mechanical irritation.1,6,7 However, there are considerable barriers to this strategy within the military due to uniform regulations as well as personal appearance and grooming standards. Early identification and treatment are of utmost importance in managing AKN in the military population to ensure reduction of morbidity, prevention of late-stage disease, and continued fitness for duty. This article reviews the clinical features, epidemiology, and treatments available for management of AKN, with a special focus on the active-duty military population.
Clinical Features and Epidemiology
Acne keloidalis nuchae is a chronic inflammatory disorder characterized by the development of keloidlike papules, pustules, and plaques on the posterior neck and occipital scalp.6 Also known as folliculitis keloidalis nuchae, AKN is seen primarily in men of African descent, though cases also have been reported in females and in a few other ethnic groups.6,7 In black males, the AKN prevalence worldwide ranges from 0.5% to 13.6%. The male to female ratio is 20 to 1.7 Although the exact cause is unknown, AKN appears to develop from chronic irritation and inflammation following localized skin injury and/or trauma. Chronic irritation from close-shaved haircuts, tight-fitting shirt collars, caps, and helmets have all been implicated as considerable risk factors.6-8
Symptoms generally develop hours to days following a close haircut and begin with the early formation of inflamed irritated papules and notable erythema.6,7 These papules may become secondarily infected and develop into pustules and/or abscesses, especially in cases in which the affected individual continues to have the hair shaved. Continued use of shared razors increases the risk for secondary infection and also raises the concern for transmission of blood-borne pathogens, as AKN lesions are quick to bleed with minor trauma.7
Over time, chronic inflammation and continued trauma of the AKN papules leads to widespread fibrosis and scar formation, as the papules coalesce into larger plaques and nodules. If left untreated, these later stages of disease can progress to chronic scarring alopecia.6
Prevention
In the general population, first-line therapy of AKN is preventative. The goal is to break the cycle of chronic inflammation, thereby preventing the development of additional lesions and subsequent scarring.7 Patients should be encouraged to avoid frequent haircuts, close shaves, hats, helmets, and tight shirt collars.6-8
A 2017 cross-sectional study by Adotama et al9 investigated recognition and management of AKN in predominantly black barbershops in an urban setting. Fifty barbers from barbershops in Oklahoma City, Oklahoma, were enrolled and interviewed for the study. Of these barbers, only 44% (22/50) were able to properly identify AKN from a photograph. Although the vast majority (94% [47/50]) were aware that razor use would aggravate the condition, only 46% (23/50) reported avoidance of cutting hair for clients with active AKN.9 This study, while limited by its small sample size, showed that many barbers may be unaware of AKN and therefore unknowingly contribute to the disease process by performing haircuts on actively inflamed scalps. For this reason, it is important to educate patients about their condition and strongly recommend lifestyle and hairstyle modifications in the management of their disease.
Acne keloidalis nuchae that is severe enough to interfere with the proper use and wear of military equipment (eg, Kevlar helmets) or maintenance of regulation grooming standards does not meet military admission standards.10,11 However, mild undiagnosed cases may be overlooked during entrance physical examinations, while many servicemembers develop AKN after entering the military.10 For these individuals, long-term avoidance of haircuts is not a realistic or obtainable therapeutic option.
Treatment
Topical Therapy
Early mild to moderate cases of AKN—papules less than 3 mm, no nodules present—may be treated with potent topical steroids. Studies have shown 2-week alternating cycles of high-potency topical steroids (2 weeks of twice-daily application followed by 2 weeks without application) for 8 to 12 weeks to be effective in reducing AKN lesions.8,12 Topical clindamycin also may be added and has demonstrated efficacy particularly when pustules are present.7,8
Intralesional Steroids
For moderate cases of AKN—papules more than 3 mm, plaques, and nodules—intralesional steroid injections may be considered. Triamcinolone may be used at a dose of 5 to 40 mg/mL administered at 4-week intervals.7 More concentrated doses will produce faster responses but also carry the known risk of side effects such as hypopigmentation in darker-skinned individuals and skin atrophy.
Systemic Therapy
Systemic therapy with oral antibiotics may be warranted as an adjunct to mild to moderate cases of AKN or in cases with clear evidence of secondary infection. Long-term tetracycline antibiotics, such as minocycline and doxycycline, may be used concurrently with topical and/or intralesional steroids.6,7 Their antibacterial and anti-inflammatory effects are useful in controlling secondary infections and reducing overall chronic inflammation.
When selecting an appropriate antibiotic for long-term use in active-duty military patients, it is important to consider their effects on duty status. Doxycycline is preferred for active-duty servicemembers because it is not duty limiting or medically disqualifying.10,13-15 However, minocycline, is restricted for use in aviators and aircrew members due to the risk for central nervous system side effects, which may include light-headedness, dizziness, and vertigo.
UV Light Therapy
UV radiation has known anti-inflammatory, immunosuppressive, and antifibrotic effects and commonly is used in the treatment of many dermatologic conditions.16 Within the last decade, targeted UVB (tUVB) radiation has shown promise as an effective alternative therapy for AKN. In 2014, Okoye et al16 conducted a prospective, randomized, split-scalp study in 11 patients with AKN. Each patient underwent treatment with a tUVB device (with peaks at 303 and 313 nm) to a randomly selected side of the scalp 3 times weekly for 16 weeks. Significant reductions in lesion count were seen on the treated side after 8 (P=.03) and 16 weeks (P=.04), with no change noted on the control side. Aside from objective lesion counts, patients completed questionnaires (n=6) regarding their treatment outcomes. Notably, 83.3% (5/6) reported marked improvement in their condition. Aside from mild transient burning and erythema of the treated area, no serious side effects were reported.16
Targeted UVB phototherapy has limited utility in an operational setting due to accessibility and operational tempo. Phototherapy units typically are available only at commands in close proximity to large medical treatment facilities. Further, the vast majority of servicemembers have duty hours that are not amenable to multiple treatment sessions per week for several months. For servicemembers in administrative roles or serving in garrison or shore billets, tUVB or narrowband UV phototherapy may be viable treatment options.
Laser Therapy
Various lasers have been used to treat AKN, including the CO2 laser, pulsed dye laser, 810-nm diode laser, and 1064-nm Nd:YAG laser.6 Kantor et al17 utilized a CO2 laser with a focused beam for surgical excision of a late-stage AKN case as early as 1986. In these patients, it was demonstrated that focused CO2 laser could be used to remove fibrotic lesions in an outpatient setting with only local anesthesia. Although only 8 patients were treated in this report, no relapses occurred.17
CO2 laser evaporation using the unfocused beam setting with 130 to 150 J/cm2 has been less successful, with relapses reported in multiple cases.6 Dragoni et al18 attempted treatment with a 595-nm pulsed dye laser with 6.5-J/cm2 fluence and 0.5-millisecond pulse but faced similar results, with lesions returning within 1 month.
There have been numerous reports of clinical improvement of AKN with the use of the 1064-nm Nd:YAG laser.6,19 Esmat et al19 treated 16 patients with a fluence of 35 to 45 J/cm2 and pulse duration of 10 to 30 milliseconds adjusted to skin type and hair thickness. An overall 82% reduction in lesion count was observed after 5 treatment sessions. Biopsies following the treatment course demonstrated a significant reduction in papule and plaque count (P=.001 and P=.011, respectively), and no clinical recurrences were noted at 12 months posttreatment.19 Similarly, Woo et al20 conducted a single-blinded, randomized, controlled trial to assess the efficacy of the Nd:YAG laser in combination with topical corticosteroid therapy vs topical corticosteroid monotherapy. Of the 20 patients treated, there was a statistically significant improvement in patients with papule-only AKN who received the laser and topical combination treatment (P=.031).20
Laser therapy may be an available treatment option for military servicemembers stationed within close proximity to military treatment facilities, with the Nd:YAG laser typically having the widest availability. Although laser therapy may be effective in early stages of disease, servicemembers would have to be amenable to limitation of future hair growth in the treated areas.
Surgical Excision
Surgical excision may be considered for large, extensive, disfiguring, and/or refractory lesions. Excision is a safe and effective method to remove tender, inflamed, keloidlike masses. Techniques for excision include electrosurgical excision with secondary intention healing, excision of a horizontal ellipse involving the posterior hairline with either primary closure or secondary intention healing, and use of a semilunar tissue expander prior to excision and closure.6 Regardless of the technique, it is important to ensure that affected tissue is excised at a depth that includes the base of the hair follicles to prevent recurrence.21
Final Thoughts
Acne keloidalis nuchae is a chronic inflammatory disease that causes considerable morbidity and can lead to chronic infection, alopecia, and disfigurement of the occipital scalp and posterior neck. Although easily preventable through the avoidance of mechanical trauma, irritation, and frequent short haircuts, the active-duty military population is restricted in their preventive measures due to current grooming and uniform standards. In this population, early identification and treatment are necessary to manage the disease to reduce patient morbidity and ensure continued operational and medical readiness. Topical and intralesional steroids may be used in mild to moderate cases. Topical and/or systemic antibiotics may be added to the treatment regimen in cases of secondary bacterial infection. For more severe refractory cases, laser therapy or complete surgical excision may be warranted.
Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder most commonly involving the occipital scalp and posterior neck characterized by the development of keloidlike papules, pustules, and plaques. If left untreated, this condition may progress to scarring alopecia. It primarily affects males of African descent, but it also may occur in females and in other ethnic groups. Although the exact underlying pathogenesis is unclear, close haircuts and chronic mechanical irritation to the posterior neck and scalp are known inciting factors. For this reason, AKN disproportionately affects active-duty military servicemembers who are held to strict grooming standards. The US Military maintains these grooming standards to ensure uniformity, self-discipline, and serviceability in operational settings.1 Regulations dictate short tapered hair, particularly on the back of the neck, which can require weekly to biweekly haircuts to maintain.1-5
First-line treatment of AKN is prevention by avoiding short haircuts and other forms of mechanical irritation.1,6,7 However, there are considerable barriers to this strategy within the military due to uniform regulations as well as personal appearance and grooming standards. Early identification and treatment are of utmost importance in managing AKN in the military population to ensure reduction of morbidity, prevention of late-stage disease, and continued fitness for duty. This article reviews the clinical features, epidemiology, and treatments available for management of AKN, with a special focus on the active-duty military population.
Clinical Features and Epidemiology
Acne keloidalis nuchae is a chronic inflammatory disorder characterized by the development of keloidlike papules, pustules, and plaques on the posterior neck and occipital scalp.6 Also known as folliculitis keloidalis nuchae, AKN is seen primarily in men of African descent, though cases also have been reported in females and in a few other ethnic groups.6,7 In black males, the AKN prevalence worldwide ranges from 0.5% to 13.6%. The male to female ratio is 20 to 1.7 Although the exact cause is unknown, AKN appears to develop from chronic irritation and inflammation following localized skin injury and/or trauma. Chronic irritation from close-shaved haircuts, tight-fitting shirt collars, caps, and helmets have all been implicated as considerable risk factors.6-8
Symptoms generally develop hours to days following a close haircut and begin with the early formation of inflamed irritated papules and notable erythema.6,7 These papules may become secondarily infected and develop into pustules and/or abscesses, especially in cases in which the affected individual continues to have the hair shaved. Continued use of shared razors increases the risk for secondary infection and also raises the concern for transmission of blood-borne pathogens, as AKN lesions are quick to bleed with minor trauma.7
Over time, chronic inflammation and continued trauma of the AKN papules leads to widespread fibrosis and scar formation, as the papules coalesce into larger plaques and nodules. If left untreated, these later stages of disease can progress to chronic scarring alopecia.6
Prevention
In the general population, first-line therapy of AKN is preventative. The goal is to break the cycle of chronic inflammation, thereby preventing the development of additional lesions and subsequent scarring.7 Patients should be encouraged to avoid frequent haircuts, close shaves, hats, helmets, and tight shirt collars.6-8
A 2017 cross-sectional study by Adotama et al9 investigated recognition and management of AKN in predominantly black barbershops in an urban setting. Fifty barbers from barbershops in Oklahoma City, Oklahoma, were enrolled and interviewed for the study. Of these barbers, only 44% (22/50) were able to properly identify AKN from a photograph. Although the vast majority (94% [47/50]) were aware that razor use would aggravate the condition, only 46% (23/50) reported avoidance of cutting hair for clients with active AKN.9 This study, while limited by its small sample size, showed that many barbers may be unaware of AKN and therefore unknowingly contribute to the disease process by performing haircuts on actively inflamed scalps. For this reason, it is important to educate patients about their condition and strongly recommend lifestyle and hairstyle modifications in the management of their disease.
Acne keloidalis nuchae that is severe enough to interfere with the proper use and wear of military equipment (eg, Kevlar helmets) or maintenance of regulation grooming standards does not meet military admission standards.10,11 However, mild undiagnosed cases may be overlooked during entrance physical examinations, while many servicemembers develop AKN after entering the military.10 For these individuals, long-term avoidance of haircuts is not a realistic or obtainable therapeutic option.
Treatment
Topical Therapy
Early mild to moderate cases of AKN—papules less than 3 mm, no nodules present—may be treated with potent topical steroids. Studies have shown 2-week alternating cycles of high-potency topical steroids (2 weeks of twice-daily application followed by 2 weeks without application) for 8 to 12 weeks to be effective in reducing AKN lesions.8,12 Topical clindamycin also may be added and has demonstrated efficacy particularly when pustules are present.7,8
Intralesional Steroids
For moderate cases of AKN—papules more than 3 mm, plaques, and nodules—intralesional steroid injections may be considered. Triamcinolone may be used at a dose of 5 to 40 mg/mL administered at 4-week intervals.7 More concentrated doses will produce faster responses but also carry the known risk of side effects such as hypopigmentation in darker-skinned individuals and skin atrophy.
Systemic Therapy
Systemic therapy with oral antibiotics may be warranted as an adjunct to mild to moderate cases of AKN or in cases with clear evidence of secondary infection. Long-term tetracycline antibiotics, such as minocycline and doxycycline, may be used concurrently with topical and/or intralesional steroids.6,7 Their antibacterial and anti-inflammatory effects are useful in controlling secondary infections and reducing overall chronic inflammation.
When selecting an appropriate antibiotic for long-term use in active-duty military patients, it is important to consider their effects on duty status. Doxycycline is preferred for active-duty servicemembers because it is not duty limiting or medically disqualifying.10,13-15 However, minocycline, is restricted for use in aviators and aircrew members due to the risk for central nervous system side effects, which may include light-headedness, dizziness, and vertigo.
UV Light Therapy
UV radiation has known anti-inflammatory, immunosuppressive, and antifibrotic effects and commonly is used in the treatment of many dermatologic conditions.16 Within the last decade, targeted UVB (tUVB) radiation has shown promise as an effective alternative therapy for AKN. In 2014, Okoye et al16 conducted a prospective, randomized, split-scalp study in 11 patients with AKN. Each patient underwent treatment with a tUVB device (with peaks at 303 and 313 nm) to a randomly selected side of the scalp 3 times weekly for 16 weeks. Significant reductions in lesion count were seen on the treated side after 8 (P=.03) and 16 weeks (P=.04), with no change noted on the control side. Aside from objective lesion counts, patients completed questionnaires (n=6) regarding their treatment outcomes. Notably, 83.3% (5/6) reported marked improvement in their condition. Aside from mild transient burning and erythema of the treated area, no serious side effects were reported.16
Targeted UVB phototherapy has limited utility in an operational setting due to accessibility and operational tempo. Phototherapy units typically are available only at commands in close proximity to large medical treatment facilities. Further, the vast majority of servicemembers have duty hours that are not amenable to multiple treatment sessions per week for several months. For servicemembers in administrative roles or serving in garrison or shore billets, tUVB or narrowband UV phototherapy may be viable treatment options.
Laser Therapy
Various lasers have been used to treat AKN, including the CO2 laser, pulsed dye laser, 810-nm diode laser, and 1064-nm Nd:YAG laser.6 Kantor et al17 utilized a CO2 laser with a focused beam for surgical excision of a late-stage AKN case as early as 1986. In these patients, it was demonstrated that focused CO2 laser could be used to remove fibrotic lesions in an outpatient setting with only local anesthesia. Although only 8 patients were treated in this report, no relapses occurred.17
CO2 laser evaporation using the unfocused beam setting with 130 to 150 J/cm2 has been less successful, with relapses reported in multiple cases.6 Dragoni et al18 attempted treatment with a 595-nm pulsed dye laser with 6.5-J/cm2 fluence and 0.5-millisecond pulse but faced similar results, with lesions returning within 1 month.
There have been numerous reports of clinical improvement of AKN with the use of the 1064-nm Nd:YAG laser.6,19 Esmat et al19 treated 16 patients with a fluence of 35 to 45 J/cm2 and pulse duration of 10 to 30 milliseconds adjusted to skin type and hair thickness. An overall 82% reduction in lesion count was observed after 5 treatment sessions. Biopsies following the treatment course demonstrated a significant reduction in papule and plaque count (P=.001 and P=.011, respectively), and no clinical recurrences were noted at 12 months posttreatment.19 Similarly, Woo et al20 conducted a single-blinded, randomized, controlled trial to assess the efficacy of the Nd:YAG laser in combination with topical corticosteroid therapy vs topical corticosteroid monotherapy. Of the 20 patients treated, there was a statistically significant improvement in patients with papule-only AKN who received the laser and topical combination treatment (P=.031).20
Laser therapy may be an available treatment option for military servicemembers stationed within close proximity to military treatment facilities, with the Nd:YAG laser typically having the widest availability. Although laser therapy may be effective in early stages of disease, servicemembers would have to be amenable to limitation of future hair growth in the treated areas.
Surgical Excision
Surgical excision may be considered for large, extensive, disfiguring, and/or refractory lesions. Excision is a safe and effective method to remove tender, inflamed, keloidlike masses. Techniques for excision include electrosurgical excision with secondary intention healing, excision of a horizontal ellipse involving the posterior hairline with either primary closure or secondary intention healing, and use of a semilunar tissue expander prior to excision and closure.6 Regardless of the technique, it is important to ensure that affected tissue is excised at a depth that includes the base of the hair follicles to prevent recurrence.21
Final Thoughts
Acne keloidalis nuchae is a chronic inflammatory disease that causes considerable morbidity and can lead to chronic infection, alopecia, and disfigurement of the occipital scalp and posterior neck. Although easily preventable through the avoidance of mechanical trauma, irritation, and frequent short haircuts, the active-duty military population is restricted in their preventive measures due to current grooming and uniform standards. In this population, early identification and treatment are necessary to manage the disease to reduce patient morbidity and ensure continued operational and medical readiness. Topical and intralesional steroids may be used in mild to moderate cases. Topical and/or systemic antibiotics may be added to the treatment regimen in cases of secondary bacterial infection. For more severe refractory cases, laser therapy or complete surgical excision may be warranted.
- Weiss AN, Arballo OM, Miletta NR, et al. Military grooming standards and their impact on skin diseases of the head and neck. Cutis. 2018;102:328, 331-333.
- US Department of the Army. Wear and Appearance of Army Uniforms and Insignia: Army Regulation 670-1. Washington, DC: Department of the Army; 2017. https://history.army.mil/html/forcestruc/docs/AR670-1.pdf. Accessed April 14, 2020.
- U.S. Headquarters Marine Corps. Marine Corps Uniform Regulations: Marine Corps Order 1020.34H. Quantico, VA: United States Marine Corps, 2018. https://www.marines.mil/portals/1/Publications/MCO%201020.34H%20v2.pdf?ver=2018-06-26-094038-137. Accessed April 14, 2020.
- Grooming standards. In: US Department of the Navy. United States Navy Uniform Regulations: NAVPERS 15665I. https://www.public.navy.mil/bupers-npc/support/uniforms/uniformregulations/chapter2/Pages/2201PersonalAppearance.aspx. Updated May 2019. Accessed April 14, 2020.
- Department of the Air Force. AFT 36-2903, Dress and Personal Appearance of Air Force Personnel. Washington, DC: Department of the Air Force, 2019. https://static.e-publishing.af.mil/production/1/af_a1/publication/afi36-2903/afi36-2903.pdf. Accessed April 14, 2020.
- Maranda EL, Simmons BJ, Nguyen AH, et al. Treatment of acne keloidalis nuchae: a systemic review of the literature. Dermatol Ther (Heidelb). 2016;6:362-378.
- Ogunbiyi A. Acne keloidalis nuchae: prevalence, impact, and management challenges. Clin Cosmet Investig Dermatol. 2016;9:483-489.
- Alexis A, Heath CR, Halder RM. Folliculitis keloidalis nuchae and pseudofolliculitis barbae: are prevention and effective treatment within reach? Dermatol Clin. 2014;32:183-191.
- Adotama P, Tinker D, Mitchell K, et al. Barber knowledge and recommendations regarding pseudofolliculitis barbae and acne keloidalis nuchae in an urban setting. JAMA Dermatol. 2017;12:1325.
- Burke KR, Larrymore DC, Cho S. Treatment considerations for US military members with sin disease. Cutis. 2019;6:329-332.
- Medical standards for Appointment, Enlistment, or Induction Into the Military Services (DoD Instruction 6130.03). Washington, DC: Department of Defense; May 6, 2018. https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/613003p.pdf. Accessed April 27, 2020.
- Callender VD, Young CM, Haverstock CL, et al. An open label study of clobetasol propionate 0.05% and betamethasone valerate 0.12% foams in treatment of mild to moderate acne keloidalis. Cutis. 2005;75:317-321.
- US Department of the Army. Standards of medical fitness. https://www.qmo.amedd.army.mil/diabetes/AR40_5012011.pdf. Published December 14, 2007. Accessed April 27, 2020.
- US Department of the Air Force. Medical examinations and standards. https://static.e-publishing.af.mil/production/1/af_sg/publication/afi48-123/afi48-123.pdf. Published November 5, 2013. Accessed April 27, 2020.
- US Navy Aeromedical Reference and Waiver Guide. https://www.med.navy.mil/sites/nmotc/nami/arwg/Documents/WaiverGuide/Complete_Waiver_Guide.pdf. Published September 4, 2019. Accessed April 14, 2020.
- Okoye GA, Rainer BM, Leung SG, et al. Improving acne keloidalis nuchae with targeted ultraviolet B treatment: a prospective, randomized split-scalp study. Br J Dermatol. 2014;17:1156-1163.
- Kantor GR, Ratz JL, Wheeland RG. Treatment of acne keloidalis nuchae with carbon dioxide laser. J Am Acad Dermatol. 1986;14(2, pt 1):263-267.
- 18. Dragoni F, Bassi A, Cannarozzo G, et al. Successful treatment of acne keloidalis nuchae resistant to conventional therapy with 1064-nm Nd:YAG laser. G Ital Dermatol Venereol. 2013;148:231-232.
- Esmat SM, Hay RMA, Zeid OMA, et al. The efficacy of laser assisted hair removal in the treatment of acne keloidalis nuchae; a pilot study. Eur J Dermatol. 2012;22:645-650.
- Woo DK, Treyger G, Henderson M, et al. Prospective controlled trial for the treatment of acne keloidalis nuchae with a long-pulsed neodymium-doped yttrium-aluminum-garnet laser. J Cutan Med Surg. 2018;22:236-238.
- Beckett N, Lawson C, Cohen G. Electrosurgical excision of acne keloidalis nuchae with secondary intention healing. J Clin Aesthet Dermatol. 2011;4:36-39.
- Weiss AN, Arballo OM, Miletta NR, et al. Military grooming standards and their impact on skin diseases of the head and neck. Cutis. 2018;102:328, 331-333.
- US Department of the Army. Wear and Appearance of Army Uniforms and Insignia: Army Regulation 670-1. Washington, DC: Department of the Army; 2017. https://history.army.mil/html/forcestruc/docs/AR670-1.pdf. Accessed April 14, 2020.
- U.S. Headquarters Marine Corps. Marine Corps Uniform Regulations: Marine Corps Order 1020.34H. Quantico, VA: United States Marine Corps, 2018. https://www.marines.mil/portals/1/Publications/MCO%201020.34H%20v2.pdf?ver=2018-06-26-094038-137. Accessed April 14, 2020.
- Grooming standards. In: US Department of the Navy. United States Navy Uniform Regulations: NAVPERS 15665I. https://www.public.navy.mil/bupers-npc/support/uniforms/uniformregulations/chapter2/Pages/2201PersonalAppearance.aspx. Updated May 2019. Accessed April 14, 2020.
- Department of the Air Force. AFT 36-2903, Dress and Personal Appearance of Air Force Personnel. Washington, DC: Department of the Air Force, 2019. https://static.e-publishing.af.mil/production/1/af_a1/publication/afi36-2903/afi36-2903.pdf. Accessed April 14, 2020.
- Maranda EL, Simmons BJ, Nguyen AH, et al. Treatment of acne keloidalis nuchae: a systemic review of the literature. Dermatol Ther (Heidelb). 2016;6:362-378.
- Ogunbiyi A. Acne keloidalis nuchae: prevalence, impact, and management challenges. Clin Cosmet Investig Dermatol. 2016;9:483-489.
- Alexis A, Heath CR, Halder RM. Folliculitis keloidalis nuchae and pseudofolliculitis barbae: are prevention and effective treatment within reach? Dermatol Clin. 2014;32:183-191.
- Adotama P, Tinker D, Mitchell K, et al. Barber knowledge and recommendations regarding pseudofolliculitis barbae and acne keloidalis nuchae in an urban setting. JAMA Dermatol. 2017;12:1325.
- Burke KR, Larrymore DC, Cho S. Treatment considerations for US military members with sin disease. Cutis. 2019;6:329-332.
- Medical standards for Appointment, Enlistment, or Induction Into the Military Services (DoD Instruction 6130.03). Washington, DC: Department of Defense; May 6, 2018. https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/613003p.pdf. Accessed April 27, 2020.
- Callender VD, Young CM, Haverstock CL, et al. An open label study of clobetasol propionate 0.05% and betamethasone valerate 0.12% foams in treatment of mild to moderate acne keloidalis. Cutis. 2005;75:317-321.
- US Department of the Army. Standards of medical fitness. https://www.qmo.amedd.army.mil/diabetes/AR40_5012011.pdf. Published December 14, 2007. Accessed April 27, 2020.
- US Department of the Air Force. Medical examinations and standards. https://static.e-publishing.af.mil/production/1/af_sg/publication/afi48-123/afi48-123.pdf. Published November 5, 2013. Accessed April 27, 2020.
- US Navy Aeromedical Reference and Waiver Guide. https://www.med.navy.mil/sites/nmotc/nami/arwg/Documents/WaiverGuide/Complete_Waiver_Guide.pdf. Published September 4, 2019. Accessed April 14, 2020.
- Okoye GA, Rainer BM, Leung SG, et al. Improving acne keloidalis nuchae with targeted ultraviolet B treatment: a prospective, randomized split-scalp study. Br J Dermatol. 2014;17:1156-1163.
- Kantor GR, Ratz JL, Wheeland RG. Treatment of acne keloidalis nuchae with carbon dioxide laser. J Am Acad Dermatol. 1986;14(2, pt 1):263-267.
- 18. Dragoni F, Bassi A, Cannarozzo G, et al. Successful treatment of acne keloidalis nuchae resistant to conventional therapy with 1064-nm Nd:YAG laser. G Ital Dermatol Venereol. 2013;148:231-232.
- Esmat SM, Hay RMA, Zeid OMA, et al. The efficacy of laser assisted hair removal in the treatment of acne keloidalis nuchae; a pilot study. Eur J Dermatol. 2012;22:645-650.
- Woo DK, Treyger G, Henderson M, et al. Prospective controlled trial for the treatment of acne keloidalis nuchae with a long-pulsed neodymium-doped yttrium-aluminum-garnet laser. J Cutan Med Surg. 2018;22:236-238.
- Beckett N, Lawson C, Cohen G. Electrosurgical excision of acne keloidalis nuchae with secondary intention healing. J Clin Aesthet Dermatol. 2011;4:36-39.
Practice Points
- Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder of the occipital scalp and posterior neck characterized by keloidlike papules, pustules, and plaques that develop following mechanical irritation.
- Military members are required to maintain short haircuts and may be disproportionately affected by AKN.
- In the military population, early identification and treatment, which includes topical steroids, oral antibiotics, UV light therapy, lasers, and surgical excision, can prevent further scarring, permanent hair loss, and disfigurement from AKN.
