Photosensitivity is an important cause of refractory facial erythema in atopic dermatitis: A retrospective study of 82 Chinese patients.

Background: Ultraviolet radiation can aggravate facial erythema in atopic dermatitis (AD) patients.

Objective: To investigate the photobiological testing results of Chinese AD patients with refractory facial erythema.

Methods: We conducted a retrospective analysis of 82 AD patients with refractory facial erythema who visited our department during 2004-2021. All of them completed phototesting and photopatch testing.

Results: 82 patients were enrolled in the study, and 53 (64.6%) were between 18 and 30 years old. 51.2% (42/82) had positive phototesting results and were considered photosensitive AD (PhAD) patients. One-third of them were both allergic to ultraviolet A and ultraviolet B. 65.9% (54/82) suffered from photoallergic contact dermatitis. Chlorpromazine (50.7%), potassium dichromate (13.2%), and thimerosal (11.8%) were the top three common photoallergens. Overall, 86.3% of AD patients with refractory facial erythema had direct photoallergy or photocontact allergy. PhAD patients had fewer allergic comorbidities than the other group (p = .007). More non-PhAD patients (55.0%) suffered from AD at 2-14 years old (p = .015).

Conclusions: Photosensitivity contributes a lot to the facial lesions of AD patients, especially in their 20s. 86.3% of these patients had direct photoallergy or photocontact allergy. Therefore, AD patients with facial erythema should undergo phototesting and photopatch testing routinely.