Chronic Actinic Dermatitis in Thailand: A Study of Clinicophotobiological Characteristics and Treatment Outcomes Over 13 years

Abstract

Background: There have been reported chronic actinic dermatitis (CAD) cases in younger patients of darker skin types, particularly in South Asian.  There remains a relative paucity of information of CAD patients in Southeast Asia generally and Thailand specifically.

Objective: Address clinicophotobiological characteristics of CAD patients and outcomes of treatments in Thailand.

Materials and Methods:  Medical records of Thai patients who diagnosed CAD and confirmed by phototesting were reviewed retrospectively from a 13-year period at a single center. Clinicophotobiological features, and outcomes of treatments were evaluated.

Results: Of 90 patients, a preponderance of patients were male with a median age at diagnosis of 55.73 ± 12.01 years; 63.3% of the patients had Fitzpatrick skin type IV. All patients presented with eczema on photodistributed areas, only 11 of those patients (12.2%) presented with eczema on both sun-exposed and sun-covered areas. Most patients demonstrated photosensitivities to both UVB and UVA (67.8%). Only 3.5% of patients had a photoallergy to a fragrance mix and balsam of peru. Fifty percent of patients had allergic contact dermatitis with fragrance mix (14.4%), balsam of peru (6.7%), nickel (6.7%), p-phenylenediamine (5.6%), and cobalt (5.6%). Less than 50% of the patients required systemic immunosuppressive treatment. Most patients had a partial response within a median time of 4 months after treatment.

Conclusion: Thai patients with CAD who have higher skin types are predominately observed in males with an earlier age at onset. Most patients exhibit both UVA and UVB photosensitivities. The coexistence of CAD and allergic contact dermatitis is common.