Jonathan Silverberg, MD, PhD, MPH
In a cross-sectional observational study of 502 Finnish patients with AD, Salava and colleagues found that severe AD was associated with older age, male sex, early age of disease onset, higher body mass index, history of smoking, concomitant asthma, palmar hyperlinearity, hand dermatitis, history of contact allergy, and history of elevated immunoglobulin E levels. Some of these findings are correlated with each other. For example, palmar hyperlinearity was previously found to be a sign associated with early-onset AD in conjunction with Filaggrin loss-of-function mutations and atopic comorbidities. 1,2 The association of AD with increased body mass index is consistent with previous studies that found associations of AD with overweight and obesity. 3 In some instances, more severe AD may precede or lead to the association, eg, asthma and hand dermatitis. These results highlight the heterogeneity and complexity of AD, especially in moderate-to-severe disease.
AD is also associated with heterogeneous triggers. In clinical practice, we commonly see patients who consider food a potential trigger for AD. To better understand the role of food-triggered AD, Li and colleagues performed a retrospective study of 372 pediatric patients with AD. They found that more than half of the children with mild, moderate, and severe AD had an immunoglobulin E–mediated food allergy. Nevertheless, food-triggered AD occurred in only 3% of patients with AD. These results are doubly important because they indicate that clinicians should address food allergies to holistically improve the health of patients with AD. On the other hand, food is rarely a reproducible trigger of AD and appropriate treatment should generally not be withheld in favor of testing for food triggers of AD.
That said, it is important to address cutaneous and extra-cutaneous infections that occur in patients with AD to prevent worsening of AD and serious sequelae of infection. Indeed, Han and colleagues examined data from the Korean National Health Insurance Service, a nationwide population-based registry including 70,205 patients with AD and an unspecified number of control patients without AD. They found that AD was associated with significantly higher odds of molluscum contagiosum, impetigo, chickenpox, otitis media, eczema herpeticum, viral warts, and viral conjunctivitis. These results are consistent with previous studies from my research group showing higher rates of these and other infections. 4-8 Anecdotally, I have seen all of these occur commonly in patients with AD, and in many instances these conditions worsen the underlying AD, eg, impetigo and eczema herpeticum.
The above-mentioned studies highlight the heterogeneity and complexity of AD, especially moderate-to-severe disease. Elsawi and colleagues conducted a survey-based study of 1065 adults with AD and found that moderate-to-severe AD was associated with increased patient burden, increased time spent managing AD symptoms, and comorbid depression. In addition, time spent managing AD symptoms was in and of itself a predictor of increased patient burden. These results underscore the many unmet needs that remain in the management of AD, with substantial patient burden from inadequate treatment as well as the inherent burden from the treatments themselves.
Additional References
1. Meng L, Wang L, Tang H, et al. Filaggrin gene mutation c.3321delA is associated with various clinical features of atopic dermatitis in the Chinese Han population. PloS One. 2014;9:e98235. Doi: 10.1371/journal.pone.0098235
2. Weidinger S, Illig T, Baurecht H, et al. Loss-of-function variations within the filaggrin gene predispose for atopic dermatitis with allergic sensitizations. J Allergy Clin Immunol. 2006;118:214-219. Doi: 10.1016/j.jaci.2006.05.004
3. Zhang A, Silverberg JI. Association of atopic dermatitis with being overweight and obese: a systematic review and metaanalysis. J Am Acad Dermatol. 2015;72:606-616.e4. Doi: 10.1016/j.jaad.2014.12.013
4. Narla S, Silverberg JI. Association between childhood atopic dermatitis and cutaneous, extracutaneous and systemic infections. Br J Dermatol. 2018;178:1467-1468. Doi: 10.1111/bjd.16482
5. Narla S, Silverberg JI. Association between atopic dermatitis and serious cutaneous, multiorgan and systemic infections in US adults. Anb Allergy Asthma Immunol. 2018;120:66-72e11. Doi: 10.1016/j.anai.2017.10.019
6. Ren Z, Silverberg JI. Association of atopic dermatitis with bacterial, fungal, viral, and sexually transmitted skin infections. Dermatitis. 2020;31:157-164. Doi: 10.1097/DER.0000000000000526
7. Serrano L, Patel KR, Silverberg JI. Association between atopic dermatitis and extracutaneous bacterial and mycobacterial infections: a systematic review and meta-analysis. J Acad Am Acad Dermatol. 2019;80:904-912. Doi: 10.1016/j.jaad.2018.11.028
8. Silverberg JI, Silverberg NB. Childhood atopic dermatitis and warts are associated with increased risk of infection: a US population-based study. J Allergy Clin Immunol. 2014;133:1041-1047. Doi: 10.1016/j.jaci.2013.08.012