Demographics and clinical presentations of 844 patients with light and dark skin types with polymorphous light eruption and chronic actinic dermatitis evaluated over 23 years

IntroductionPolymorphous light eruption (PMLE) and chronic actinic dermatitis (CAD) have been classically described in White individuals, although recent studies have reported higher prevalence in patients with dark skin types, particularly African Americans. ObjectiveTo evaluate for differences in demographic, and clinical features between persons with light and dark skin types who have PMLE and CAD. MethodsRetrospective review of patients with PMLE and CAD who were diagnosed from January 1, 1998, through November 31, 2021, at a single academic dermatology center. Results/DiscussionA total of 844 patients (725 [85.9%] female; mean [SD] age of onset: 41.7 [16.9] years) were diagnosed with PMLE, and 60 patients (22 [36.6%] female; mean age, [SD]: 60.6 [10.6] years) of age at presentation, disease duration of 8.2 [7.3] years were diagnosed with CAD. Although just over 50% of the general clinic population was White, the prevalence of PMLE and CAD was significantly higher in dark-skinned individuals compared to light-skinned individuals (PMLE: 625 [74.0%] vs. 219 [25.9%], p value < .001; CAD: 43 [71.6%] vs. 17 [28.3%], p value = .003) respectively. The pinpoint papular variant of PMLE (PP-PMLE) was predominantly seen in dark-skinned individuals. ConclusionA substantial proportion of PMLE and CAD cases are present in dark-skinned individuals. PP-PMLE can be mistaken for lichen nitidus. As such, recognition of this entity is important for adequate evaluation and management of patients with PMLE.