Daniel Gutierrez, MD

To the Editor:

In a 2010 landmark paper, researchers reported that the Preexposure Prophylaxis Initiative (iPrEx) trial demonstrated that once-daily pre-exposure prophylaxis (PrEP) with emtricitabine plus tenofovir disoproxil fumarate, which was approved by the US Food and Drug Administration (FDA) and packaged together as Truvada (Gilead Sciences, Inc), achieved a 44% reduction in the incidence of HIV infection compared to the placebo arm of the study (64/1248 HIV infections in the placebo group vs 36/1251 in the intervention group).¹ Subsequently, the US Department of Health and Human Services proposed an initiative to reduce new HIV infections by 90% by 2030.² The Centers for Disease Control and Prevention estimates that 1.1 million Americans have an indication for PrEP, yet only approximately 400,000 individuals currently take PrEP.^3,4

Increasing awareness of PrEP and its indications is essential because PrEP exerts its greatest benefit when used broadly. Awareness among primary care and infectious disease physicians was reported at 76%⁵; awareness among other medical specialists remains unknown. Awareness of PrEP among dermatologists is important because dermatologists play an important role in the diagnosis and treatment of many sexually transmitted infections (STIs), which are a risk factor for transmission of HIV. As providers who treat STIs, dermatologists are in a prime position to educate patients about PrEP, refer them for treatment, and prescribe the regimen. We conducted a survey to assess dermatologists’ knowledge about and attitudes toward PrEP. We also provide a brief summary of prescribing information about common PrEP regimens to fill in the knowledge gap among dermatologists as a way to promote its utilization.

An electronic survey was distributed to 486 members of the Association of Professors of Dermatology based in the United States using the web-based survey application REDCap. The study was approved by the New York University Grossman School of Medicine (New York, New York) institutional review board. Eighty-one anonymous survey responses were completed and returned (response rate, 16.6%). Data were analyzed using descriptive statistics.

The mean age (SD) of respondents was 39.1 (9.7) years; 49.4% (40/81) were male; and 74.1% (60/81) were attending physicians, with a mean (SD) of 9.4 (8.6) years of practice. Clinical practices were predominantly from the northeast (46.9% [38/81]) and mostly in an academic setting (74.1% [60/81]). As shown in Table 1, most surveyed dermatologists reported being aware of PrEP (93.8% [76/81]), but a minority (42.0% [34/81]) were familiar with indications for its use; even fewer (4.9% [4/81]) were current prescribers. Referral to other physicians for PrEP was reported by 58.0% (47/81) of respondents.

Despite respondents’ awareness of PrEP as a preventive measure (93.8% [76/81]) and their willingness to prescribe it (67.9% [55/81]), many reported being largely unfamiliar with its indications (58.0% [47/81]) and uncomfortable discussing its adverse effects (72.8% [59/81]), conducting appropriate laboratory monitoring (84.0% [68/81]), and refilling existing prescriptions (77.8% [63/81]). Respondents’ lack of education about PrEP was a barrier to prescribing (51.9% [42/81] to 59.3% [48/81]) and explains why a small minority (4.9% [4/81]) currently prescribe the regimen.

Our study sought to characterize current clinical knowledge about and practice patterns of PrEP among dermatologists. Dermatologists often encounter patients who present with an STI, which is a risk factor for HIV infection, but our survey respondents reported several barriers to utilizing PrEP. The difference in the degree of respondents’ willingness to prescribe PrEP (67.9%) and those who self-identified as prescribers (4.9%) suggests a role for dermatologists in prescribing or discussing PrEP with their patients—albeit a currently undefined role.

The results of our study suggested that half (41/81) of dermatologists believe that PrEP prescription is out of their scope of practice, likely due to a combination of scheduling, laboratory monitoring, and medicolegal concerns. For dermatologists who are interested in being PrEP prescribers, our results suggested that closing the knowledge gap around PrEP among dermatologists through training and education could improve comfort with this medication and lead to changes in practice to prevent the spread of HIV infection.

PrEP is indicated for HIV-negative patients who have HIV-positive sexual partners, utilize barrier protection methods inconsistently, or had a diagnosis of an STI in the last 6 months.⁶ In 2012, the FDA approved once-daily use of emtricitabine plus tenofovir for primary prevention of HIV infection. Post hoc analysis of iPrEx trial data revealed that once-daily PrEP taken regularly had a 92% to 100% protective effect against HIV.⁷

Regrettably, real-world uptake of PrEP has been slower than desired. The most recent data (2021) show that nearly 1 million individuals worldwide take PrEP; however, this represents only approximately one-third of those eligible.⁸ Utilization is notably lower among Black and Latino populations who stand to gain the most from PrEP given their higher risk of contracting HIV compared to their White counterparts.⁹ As such, improving access to PrEP through expanded provider awareness is essential to decrease the risk for HIV infection and transmission.

Emtricitabine plus tenofovir is safe and well tolerated; more common adverse effects are headache, nausea, vomiting, rash, and loss of appetite. Tenofovir likely decreases bone mineral density, even in HIV-negative patients¹⁰; mineralization seems to recover after the medication is discontinued.¹¹ Rarely, tenofovir can increase the level of creatinine and hepatic transaminases; a recent report on its long-term side effects has shown small nonprogressive decreases in glomerular filtration rate.¹² Monitoring kidney function is a component of prescribing PrEP (Table 2).

In 2019, emtricitabine plus tenofovir was reformulated with tenofovir alafenamide; the new combination regimen received FDA approval for once-daily PrEP under the brand name Descovy (Gilead Sciences, Inc). The new formulation results in a lower blood concentration of tenofovir and has been reported to present less of a risk for bone and kidney toxicity.^13,14

Notably, emtricitabine plus tenofovir alafenamide might accumulate faster in peripheral lymphatic tissue than emtricitabine plus tenofovir disoproxil fumarate. This property has led to a new regimen known as “on-demand PrEP,” which follows a 2-1-1 dosing regimen: Patients take a double dose 2 to 24 hours before sexual activity, 1 dose on the day of sexual activity, and 1 dose the day after sexual activity.¹⁵ Because some patients at risk for HIV infection might not be consistently sexually active, on-demand PrEP allows them to cycle on and off the medication. Barriers to implementing on-demand PrEP include requiring that sexual activity be planned and an adverse effect profile similar to daily-use PrEP.¹⁶

The FDA recently approved a long-acting, once-monthly combination injectable PrEP of cabotegravir and rilpivirine.¹⁷ The long duration of action of this PrEP will benefit patients who report problems with medication adherence.

Our study demonstrates low frequency in prescribing patterns of PrEP among dermatologists and suggests that an addressable barrier to such prescribing is the lack of knowledge on how to prescribe it safely, which warrants further clinical investigation. We summarize an approach to prescribing PrEP in Table 2. Our study was limited by a small sample of mostly academic dermatologists and selection bias, which may diminish the generalizability of findings. A study of a larger, more representative group of dermatologists likely would show different prescribing patterns and degrees of knowledge about PrEP. Research is needed to study the impact of educational interventions that aim to increase both knowledge and prescribing of PrEP among dermatologists.

To the Editor:

In a 2010 landmark paper, researchers reported that the Preexposure Prophylaxis Initiative (iPrEx) trial demonstrated that once-daily pre-exposure prophylaxis (PrEP) with emtricitabine plus tenofovir disoproxil fumarate, which was approved by the US Food and Drug Administration (FDA) and packaged together as Truvada (Gilead Sciences, Inc), achieved a 44% reduction in the incidence of HIV infection compared to the placebo arm of the study (64/1248 HIV infections in the placebo group vs 36/1251 in the intervention group).¹ Subsequently, the US Department of Health and Human Services proposed an initiative to reduce new HIV infections by 90% by 2030.² The Centers for Disease Control and Prevention estimates that 1.1 million Americans have an indication for PrEP, yet only approximately 400,000 individuals currently take PrEP.^3,4

Increasing awareness of PrEP and its indications is essential because PrEP exerts its greatest benefit when used broadly. Awareness among primary care and infectious disease physicians was reported at 76%⁵; awareness among other medical specialists remains unknown. Awareness of PrEP among dermatologists is important because dermatologists play an important role in the diagnosis and treatment of many sexually transmitted infections (STIs), which are a risk factor for transmission of HIV. As providers who treat STIs, dermatologists are in a prime position to educate patients about PrEP, refer them for treatment, and prescribe the regimen. We conducted a survey to assess dermatologists’ knowledge about and attitudes toward PrEP. We also provide a brief summary of prescribing information about common PrEP regimens to fill in the knowledge gap among dermatologists as a way to promote its utilization.

An electronic survey was distributed to 486 members of the Association of Professors of Dermatology based in the United States using the web-based survey application REDCap. The study was approved by the New York University Grossman School of Medicine (New York, New York) institutional review board. Eighty-one anonymous survey responses were completed and returned (response rate, 16.6%). Data were analyzed using descriptive statistics.

The mean age (SD) of respondents was 39.1 (9.7) years; 49.4% (40/81) were male; and 74.1% (60/81) were attending physicians, with a mean (SD) of 9.4 (8.6) years of practice. Clinical practices were predominantly from the northeast (46.9% [38/81]) and mostly in an academic setting (74.1% [60/81]). As shown in Table 1, most surveyed dermatologists reported being aware of PrEP (93.8% [76/81]), but a minority (42.0% [34/81]) were familiar with indications for its use; even fewer (4.9% [4/81]) were current prescribers. Referral to other physicians for PrEP was reported by 58.0% (47/81) of respondents.

Despite respondents’ awareness of PrEP as a preventive measure (93.8% [76/81]) and their willingness to prescribe it (67.9% [55/81]), many reported being largely unfamiliar with its indications (58.0% [47/81]) and uncomfortable discussing its adverse effects (72.8% [59/81]), conducting appropriate laboratory monitoring (84.0% [68/81]), and refilling existing prescriptions (77.8% [63/81]). Respondents’ lack of education about PrEP was a barrier to prescribing (51.9% [42/81] to 59.3% [48/81]) and explains why a small minority (4.9% [4/81]) currently prescribe the regimen.

Our study sought to characterize current clinical knowledge about and practice patterns of PrEP among dermatologists. Dermatologists often encounter patients who present with an STI, which is a risk factor for HIV infection, but our survey respondents reported several barriers to utilizing PrEP. The difference in the degree of respondents’ willingness to prescribe PrEP (67.9%) and those who self-identified as prescribers (4.9%) suggests a role for dermatologists in prescribing or discussing PrEP with their patients—albeit a currently undefined role.

The results of our study suggested that half (41/81) of dermatologists believe that PrEP prescription is out of their scope of practice, likely due to a combination of scheduling, laboratory monitoring, and medicolegal concerns. For dermatologists who are interested in being PrEP prescribers, our results suggested that closing the knowledge gap around PrEP among dermatologists through training and education could improve comfort with this medication and lead to changes in practice to prevent the spread of HIV infection.

PrEP is indicated for HIV-negative patients who have HIV-positive sexual partners, utilize barrier protection methods inconsistently, or had a diagnosis of an STI in the last 6 months.⁶ In 2012, the FDA approved once-daily use of emtricitabine plus tenofovir for primary prevention of HIV infection. Post hoc analysis of iPrEx trial data revealed that once-daily PrEP taken regularly had a 92% to 100% protective effect against HIV.⁷

Regrettably, real-world uptake of PrEP has been slower than desired. The most recent data (2021) show that nearly 1 million individuals worldwide take PrEP; however, this represents only approximately one-third of those eligible.⁸ Utilization is notably lower among Black and Latino populations who stand to gain the most from PrEP given their higher risk of contracting HIV compared to their White counterparts.⁹ As such, improving access to PrEP through expanded provider awareness is essential to decrease the risk for HIV infection and transmission.

Emtricitabine plus tenofovir is safe and well tolerated; more common adverse effects are headache, nausea, vomiting, rash, and loss of appetite. Tenofovir likely decreases bone mineral density, even in HIV-negative patients¹⁰; mineralization seems to recover after the medication is discontinued.¹¹ Rarely, tenofovir can increase the level of creatinine and hepatic transaminases; a recent report on its long-term side effects has shown small nonprogressive decreases in glomerular filtration rate.¹² Monitoring kidney function is a component of prescribing PrEP (Table 2).

In 2019, emtricitabine plus tenofovir was reformulated with tenofovir alafenamide; the new combination regimen received FDA approval for once-daily PrEP under the brand name Descovy (Gilead Sciences, Inc). The new formulation results in a lower blood concentration of tenofovir and has been reported to present less of a risk for bone and kidney toxicity.^13,14

Notably, emtricitabine plus tenofovir alafenamide might accumulate faster in peripheral lymphatic tissue than emtricitabine plus tenofovir disoproxil fumarate. This property has led to a new regimen known as “on-demand PrEP,” which follows a 2-1-1 dosing regimen: Patients take a double dose 2 to 24 hours before sexual activity, 1 dose on the day of sexual activity, and 1 dose the day after sexual activity.¹⁵ Because some patients at risk for HIV infection might not be consistently sexually active, on-demand PrEP allows them to cycle on and off the medication. Barriers to implementing on-demand PrEP include requiring that sexual activity be planned and an adverse effect profile similar to daily-use PrEP.¹⁶

The FDA recently approved a long-acting, once-monthly combination injectable PrEP of cabotegravir and rilpivirine.¹⁷ The long duration of action of this PrEP will benefit patients who report problems with medication adherence.

Our study demonstrates low frequency in prescribing patterns of PrEP among dermatologists and suggests that an addressable barrier to such prescribing is the lack of knowledge on how to prescribe it safely, which warrants further clinical investigation. We summarize an approach to prescribing PrEP in Table 2. Our study was limited by a small sample of mostly academic dermatologists and selection bias, which may diminish the generalizability of findings. A study of a larger, more representative group of dermatologists likely would show different prescribing patterns and degrees of knowledge about PrEP. Research is needed to study the impact of educational interventions that aim to increase both knowledge and prescribing of PrEP among dermatologists.

To the Editor:

In a 2010 landmark paper, researchers reported that the Preexposure Prophylaxis Initiative (iPrEx) trial demonstrated that once-daily pre-exposure prophylaxis (PrEP) with emtricitabine plus tenofovir disoproxil fumarate, which was approved by the US Food and Drug Administration (FDA) and packaged together as Truvada (Gilead Sciences, Inc), achieved a 44% reduction in the incidence of HIV infection compared to the placebo arm of the study (64/1248 HIV infections in the placebo group vs 36/1251 in the intervention group).¹ Subsequently, the US Department of Health and Human Services proposed an initiative to reduce new HIV infections by 90% by 2030.² The Centers for Disease Control and Prevention estimates that 1.1 million Americans have an indication for PrEP, yet only approximately 400,000 individuals currently take PrEP.^3,4

Increasing awareness of PrEP and its indications is essential because PrEP exerts its greatest benefit when used broadly. Awareness among primary care and infectious disease physicians was reported at 76%⁵; awareness among other medical specialists remains unknown. Awareness of PrEP among dermatologists is important because dermatologists play an important role in the diagnosis and treatment of many sexually transmitted infections (STIs), which are a risk factor for transmission of HIV. As providers who treat STIs, dermatologists are in a prime position to educate patients about PrEP, refer them for treatment, and prescribe the regimen. We conducted a survey to assess dermatologists’ knowledge about and attitudes toward PrEP. We also provide a brief summary of prescribing information about common PrEP regimens to fill in the knowledge gap among dermatologists as a way to promote its utilization.

An electronic survey was distributed to 486 members of the Association of Professors of Dermatology based in the United States using the web-based survey application REDCap. The study was approved by the New York University Grossman School of Medicine (New York, New York) institutional review board. Eighty-one anonymous survey responses were completed and returned (response rate, 16.6%). Data were analyzed using descriptive statistics.

The mean age (SD) of respondents was 39.1 (9.7) years; 49.4% (40/81) were male; and 74.1% (60/81) were attending physicians, with a mean (SD) of 9.4 (8.6) years of practice. Clinical practices were predominantly from the northeast (46.9% [38/81]) and mostly in an academic setting (74.1% [60/81]). As shown in Table 1, most surveyed dermatologists reported being aware of PrEP (93.8% [76/81]), but a minority (42.0% [34/81]) were familiar with indications for its use; even fewer (4.9% [4/81]) were current prescribers. Referral to other physicians for PrEP was reported by 58.0% (47/81) of respondents.

Despite respondents’ awareness of PrEP as a preventive measure (93.8% [76/81]) and their willingness to prescribe it (67.9% [55/81]), many reported being largely unfamiliar with its indications (58.0% [47/81]) and uncomfortable discussing its adverse effects (72.8% [59/81]), conducting appropriate laboratory monitoring (84.0% [68/81]), and refilling existing prescriptions (77.8% [63/81]). Respondents’ lack of education about PrEP was a barrier to prescribing (51.9% [42/81] to 59.3% [48/81]) and explains why a small minority (4.9% [4/81]) currently prescribe the regimen.

Our study sought to characterize current clinical knowledge about and practice patterns of PrEP among dermatologists. Dermatologists often encounter patients who present with an STI, which is a risk factor for HIV infection, but our survey respondents reported several barriers to utilizing PrEP. The difference in the degree of respondents’ willingness to prescribe PrEP (67.9%) and those who self-identified as prescribers (4.9%) suggests a role for dermatologists in prescribing or discussing PrEP with their patients—albeit a currently undefined role.

The results of our study suggested that half (41/81) of dermatologists believe that PrEP prescription is out of their scope of practice, likely due to a combination of scheduling, laboratory monitoring, and medicolegal concerns. For dermatologists who are interested in being PrEP prescribers, our results suggested that closing the knowledge gap around PrEP among dermatologists through training and education could improve comfort with this medication and lead to changes in practice to prevent the spread of HIV infection.

PrEP is indicated for HIV-negative patients who have HIV-positive sexual partners, utilize barrier protection methods inconsistently, or had a diagnosis of an STI in the last 6 months.⁶ In 2012, the FDA approved once-daily use of emtricitabine plus tenofovir for primary prevention of HIV infection. Post hoc analysis of iPrEx trial data revealed that once-daily PrEP taken regularly had a 92% to 100% protective effect against HIV.⁷

Regrettably, real-world uptake of PrEP has been slower than desired. The most recent data (2021) show that nearly 1 million individuals worldwide take PrEP; however, this represents only approximately one-third of those eligible.⁸ Utilization is notably lower among Black and Latino populations who stand to gain the most from PrEP given their higher risk of contracting HIV compared to their White counterparts.⁹ As such, improving access to PrEP through expanded provider awareness is essential to decrease the risk for HIV infection and transmission.

Emtricitabine plus tenofovir is safe and well tolerated; more common adverse effects are headache, nausea, vomiting, rash, and loss of appetite. Tenofovir likely decreases bone mineral density, even in HIV-negative patients¹⁰; mineralization seems to recover after the medication is discontinued.¹¹ Rarely, tenofovir can increase the level of creatinine and hepatic transaminases; a recent report on its long-term side effects has shown small nonprogressive decreases in glomerular filtration rate.¹² Monitoring kidney function is a component of prescribing PrEP (Table 2).

In 2019, emtricitabine plus tenofovir was reformulated with tenofovir alafenamide; the new combination regimen received FDA approval for once-daily PrEP under the brand name Descovy (Gilead Sciences, Inc). The new formulation results in a lower blood concentration of tenofovir and has been reported to present less of a risk for bone and kidney toxicity.^13,14

Notably, emtricitabine plus tenofovir alafenamide might accumulate faster in peripheral lymphatic tissue than emtricitabine plus tenofovir disoproxil fumarate. This property has led to a new regimen known as “on-demand PrEP,” which follows a 2-1-1 dosing regimen: Patients take a double dose 2 to 24 hours before sexual activity, 1 dose on the day of sexual activity, and 1 dose the day after sexual activity.¹⁵ Because some patients at risk for HIV infection might not be consistently sexually active, on-demand PrEP allows them to cycle on and off the medication. Barriers to implementing on-demand PrEP include requiring that sexual activity be planned and an adverse effect profile similar to daily-use PrEP.¹⁶

The FDA recently approved a long-acting, once-monthly combination injectable PrEP of cabotegravir and rilpivirine.¹⁷ The long duration of action of this PrEP will benefit patients who report problems with medication adherence.

Our study demonstrates low frequency in prescribing patterns of PrEP among dermatologists and suggests that an addressable barrier to such prescribing is the lack of knowledge on how to prescribe it safely, which warrants further clinical investigation. We summarize an approach to prescribing PrEP in Table 2. Our study was limited by a small sample of mostly academic dermatologists and selection bias, which may diminish the generalizability of findings. A study of a larger, more representative group of dermatologists likely would show different prescribing patterns and degrees of knowledge about PrEP. Research is needed to study the impact of educational interventions that aim to increase both knowledge and prescribing of PrEP among dermatologists.

To the Editor: 
A 60-year-old woman presented for evaluation of a 1-year history of left hallux nail plate dystrophy and proximal nail fold inflammation. Her medical history included Cushing disease with associated uncontrolled diabetes mellitus (DM) and a remote history of cutaneous lichen planus (LP) that resolved 15 years prior to presentation. She noted improvement during intravenous courses of antibiotics for other infections.   

Examination of the left hallux revealed onycholysis, loss of the nail plate, and a yellow fibrinous base alongside erosion, erythema, and edema of the proximal toenail fold (Figure 1). The left second toe pad was markedly tender to palpation with scant exudate expressed from underneath the nail bed. Two biopsies of the hallux were performed. The proximal nail fold specimen revealed mild epidermal hyperplasia, and the nail bed demonstrated a nonspecific ulcer that was negative for acid-fast bacilli and fungi.  

Treatment over 2 months with cephalexin yielded improvement in both erythema and edema. Initial and repeat nail plate cultures grew ampicillin- and penicillin-sensitive Enterococcus faecalis. Magnetic resonance imaging was performed to evaluate for osteomyelitis because of lack of resolution. Results demonstrated osteomyelitis of the distal tuft of the left hallux and the distal phalanx of the second toe (Figure 2). Vascular surgery evaluation revealed no evidence of large vessel arterial insufficiency. She was started on amoxicillin for superficial Enterococcus and ciprofloxacin for underlying enteric bacilli. The persistence of infection was attributed to microvascular disease secondary to the patient's associated DM. Months later, due to suspected worsening of osteomyelitis, she underwent treatment with oral fluconazole to cover potential fungal co-infection and intravenous vancomycin and piperacillin-tazobactam for broad-spectrum antibacterial coverage. She was eventually transitioned to antimicrobial agents including amoxicillin-clavulanate potassium and topical mupirocin with improvement in periungual erythema and edema.  

On subsequent dermatologic evaluation after 1 month, she presented with pterygium and loss of all nail plates on the left foot. The nail bed now had a violaceous color and was studded with milia. The clinical findings were suggestive of LP, consistent with her history of LP. In light of these new findings, both topical corticosteroids and retinoids were utilized for treatment without remarkable benefit. The patient declined further management with systemic medications. 

We report a case of nail LP associated with underlying radiographic osteomyelitis. Erosive nail LP has been associated with underlying osteomyelitis of the phalanx.¹ Our patient developed these manifestations in the setting of Cushing disease, a unique finding given that many report improvement of LP with systemic corticosteroids.^2,3 Tacrolimus, a calcineurin inhibitor, has been used in oral or topical formulations for lower extremity ulcers caused by LP as well as nail LP.^1,4 Long-term prognosis of nail LP is poor, with high relapse rates and permanent damage to the nail unit.² It is important to be aware that LP of the nail unit may cause radiographic changes of osteomyelitis that are not infectious in nature. 
 
 

To the Editor: 
A 60-year-old woman presented for evaluation of a 1-year history of left hallux nail plate dystrophy and proximal nail fold inflammation. Her medical history included Cushing disease with associated uncontrolled diabetes mellitus (DM) and a remote history of cutaneous lichen planus (LP) that resolved 15 years prior to presentation. She noted improvement during intravenous courses of antibiotics for other infections.   

Examination of the left hallux revealed onycholysis, loss of the nail plate, and a yellow fibrinous base alongside erosion, erythema, and edema of the proximal toenail fold (Figure 1). The left second toe pad was markedly tender to palpation with scant exudate expressed from underneath the nail bed. Two biopsies of the hallux were performed. The proximal nail fold specimen revealed mild epidermal hyperplasia, and the nail bed demonstrated a nonspecific ulcer that was negative for acid-fast bacilli and fungi.  

Treatment over 2 months with cephalexin yielded improvement in both erythema and edema. Initial and repeat nail plate cultures grew ampicillin- and penicillin-sensitive Enterococcus faecalis. Magnetic resonance imaging was performed to evaluate for osteomyelitis because of lack of resolution. Results demonstrated osteomyelitis of the distal tuft of the left hallux and the distal phalanx of the second toe (Figure 2). Vascular surgery evaluation revealed no evidence of large vessel arterial insufficiency. She was started on amoxicillin for superficial Enterococcus and ciprofloxacin for underlying enteric bacilli. The persistence of infection was attributed to microvascular disease secondary to the patient's associated DM. Months later, due to suspected worsening of osteomyelitis, she underwent treatment with oral fluconazole to cover potential fungal co-infection and intravenous vancomycin and piperacillin-tazobactam for broad-spectrum antibacterial coverage. She was eventually transitioned to antimicrobial agents including amoxicillin-clavulanate potassium and topical mupirocin with improvement in periungual erythema and edema.  

On subsequent dermatologic evaluation after 1 month, she presented with pterygium and loss of all nail plates on the left foot. The nail bed now had a violaceous color and was studded with milia. The clinical findings were suggestive of LP, consistent with her history of LP. In light of these new findings, both topical corticosteroids and retinoids were utilized for treatment without remarkable benefit. The patient declined further management with systemic medications. 

We report a case of nail LP associated with underlying radiographic osteomyelitis. Erosive nail LP has been associated with underlying osteomyelitis of the phalanx.¹ Our patient developed these manifestations in the setting of Cushing disease, a unique finding given that many report improvement of LP with systemic corticosteroids.^2,3 Tacrolimus, a calcineurin inhibitor, has been used in oral or topical formulations for lower extremity ulcers caused by LP as well as nail LP.^1,4 Long-term prognosis of nail LP is poor, with high relapse rates and permanent damage to the nail unit.² It is important to be aware that LP of the nail unit may cause radiographic changes of osteomyelitis that are not infectious in nature. 
 
 

To the Editor: 
A 60-year-old woman presented for evaluation of a 1-year history of left hallux nail plate dystrophy and proximal nail fold inflammation. Her medical history included Cushing disease with associated uncontrolled diabetes mellitus (DM) and a remote history of cutaneous lichen planus (LP) that resolved 15 years prior to presentation. She noted improvement during intravenous courses of antibiotics for other infections.   

Examination of the left hallux revealed onycholysis, loss of the nail plate, and a yellow fibrinous base alongside erosion, erythema, and edema of the proximal toenail fold (Figure 1). The left second toe pad was markedly tender to palpation with scant exudate expressed from underneath the nail bed. Two biopsies of the hallux were performed. The proximal nail fold specimen revealed mild epidermal hyperplasia, and the nail bed demonstrated a nonspecific ulcer that was negative for acid-fast bacilli and fungi.  

Treatment over 2 months with cephalexin yielded improvement in both erythema and edema. Initial and repeat nail plate cultures grew ampicillin- and penicillin-sensitive Enterococcus faecalis. Magnetic resonance imaging was performed to evaluate for osteomyelitis because of lack of resolution. Results demonstrated osteomyelitis of the distal tuft of the left hallux and the distal phalanx of the second toe (Figure 2). Vascular surgery evaluation revealed no evidence of large vessel arterial insufficiency. She was started on amoxicillin for superficial Enterococcus and ciprofloxacin for underlying enteric bacilli. The persistence of infection was attributed to microvascular disease secondary to the patient's associated DM. Months later, due to suspected worsening of osteomyelitis, she underwent treatment with oral fluconazole to cover potential fungal co-infection and intravenous vancomycin and piperacillin-tazobactam for broad-spectrum antibacterial coverage. She was eventually transitioned to antimicrobial agents including amoxicillin-clavulanate potassium and topical mupirocin with improvement in periungual erythema and edema.  

On subsequent dermatologic evaluation after 1 month, she presented with pterygium and loss of all nail plates on the left foot. The nail bed now had a violaceous color and was studded with milia. The clinical findings were suggestive of LP, consistent with her history of LP. In light of these new findings, both topical corticosteroids and retinoids were utilized for treatment without remarkable benefit. The patient declined further management with systemic medications. 

We report a case of nail LP associated with underlying radiographic osteomyelitis. Erosive nail LP has been associated with underlying osteomyelitis of the phalanx.¹ Our patient developed these manifestations in the setting of Cushing disease, a unique finding given that many report improvement of LP with systemic corticosteroids.^2,3 Tacrolimus, a calcineurin inhibitor, has been used in oral or topical formulations for lower extremity ulcers caused by LP as well as nail LP.^1,4 Long-term prognosis of nail LP is poor, with high relapse rates and permanent damage to the nail unit.² It is important to be aware that LP of the nail unit may cause radiographic changes of osteomyelitis that are not infectious in nature.