Testing Is Key to Identifying Photoaggravated Atopic Dermatitis

Photoaggravated atopic dermatitis (PAD) is an under-reported and under-recognized subtype of atopic dermatitis (AD) that affects from 1.4% to 16% of the AD population. Because it significantly affects quality of life, researchers conducted a study to better identify demographic and clinical PAD features. They published their findings in a study published in JAMA Dermatology.

The researchers found that of the patients with AD who received photoinvestigation, 14% were diagnosed with PAD. The median age of those patients was 45 years of age; median age of onset was 37 years. PAD was concurrent with AD in 13% of patients. Patients with skin phototypes (SPT) I through IV were mostly White (94%). Those with SPTs V and VI were primarily Afro Caribbean (19%) and South Asian (77%).

Nearly half of patients (46%) with PAD reported that less than an hour of exposure would trigger symptoms. About the same number (47%) said sunlight through a window would trigger a reaction. Most of the patients with PAD (78%) reported very or extremely impaired quality of life because of the disorder, investigators noted. Those whose symptoms were triggered by light through a glass window experienced worse quality of life than others with PAD.

Broadband UV radiation provocation test returned a positive result in 93% of patients with PAD. Reactions included varying degrees of redness with dryness, scaling, and swelling. Of the patients who received photopatch testing, 15% had a positive reaction. Red flags that indicate possible PAD include seasonal aggravation, and eczema provoked by sunlight, as well as a history of flares during holidays.

Although the researchers had a quality dataset and detailed data collection tools, they used data from 1 specialist center, which may limit generalizability. Self-reported data may have also affected the results.

Despite the study limitations, the researchers concluded that physicians should consider phototesting to confirm PAD, followed by personalized care. “The study’s findings suggest that improved knowledge of PAD presentation, demographic aspects, and photoinvestigation can assist patient diagnosis and treatment,” they stated.

Reference

Rutter KJ, Farrar MD, Marjanovic EJ, Rhodes LE. Clinicophotobiological Characterization of Photoaggravated Atopic Dermatitis [published online ahead of print, 2022 Jul 27]. JAMA Dermatol. 2022;10.1001/jamadermatol.2022.2823. doi:10.1001/jamadermatol.2022.2823