Photoaggravated atopic dermatitis (PAD) affects nearly 1.4% to 16% of patients with AD but remains inadequately characterized with limited published data.

The present study thus provides a detailed clinical and photobiological characterization of PAD. It used the data collected from 120 consecutive patients diagnosed with PAD and analyzed them.

The study observed:

• Fourteen percent received PAD diagnosis (with 58% female; median age 45 years; range, 5-83 years; skin phototypes [SPTs] I-VI) among 869 patients who underwent photo investigation.
• Eighty-seven percent of the diagnosed cases were adults.
• History of AD in all patients, and most showed sunlight-provoked or photo-distributed eczema; the median age at photosensitivity onset was 37 years (range, 1-72 years).
• Past-year Dermatology Life Quality Index score to be >10 in 78%.  
• Vitamin D (25-hydroxyvitamin D) level insufficiency or deficiency in 69%.
• Positive broadband ultraviolet (UV) radiation provocation test results in 93% of patients.
• Sensitivity to UV-A, UV-B and/or visible light in 23% of patients with abnormal monochromator phototest findings and UV-A of 350 ± 10 nm as the most prevalent wavelength.
• Positive photopatch test reactions in 15% of patients.
• Patients with SPTs V to VI to be younger at photosensitivity onset, more likely to be female, and contain lower vitamin D status and a higher frequency of abnormal monochromator phototest findings.

This case series study shows that PAD affects patients of different ages and SPTs and is associated with substantially impaired quality of life. Thus, confirming PAD through phototesting may provide better-personalized patient care by identifying stimulating wavelengths, relevant photocontact allergies and appropriate photoprotection advice.

Source: Rutter KJ, Farrar MD, Marjanovic EJ, et al. Clinicophotobiological characterization of photoaggravated atopic dermatitis. JAMA Dermatol. 2022;158(9):1022-30.