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The following is a summary of “Continuum of light sensitivity in atopic dermatitis: A retrospective analysis of 139 cases in Scotland,” published in the November 2024 issue of Dermatology by Chaiyabutr et al. 

Photosensitivity in atopic dermatitis (AD) has been characterized in previous reports, though with differing terminology and criteria.  

Researchers conducted a retrospective study to evaluate outcomes in 139 individuals with AD referred for photodiagnostic testing and to establish diagnostic criteria for photosensitivity in AD.  

They reviewed clinical and photodiagnostic data from 139 individuals with AD, categorizing photosensitivity into 3 groups: photoexacerbated AD, photosensitive AD, and chronic actinic dermatitis.  

The results showed that the mean age of the patient cohort was 42.6 ± 16.7 years, with 61.9% being men. Among patients with photoexacerbated AD, 51.1% had normal monochromator phototesting, while 7.9% of those with photosensitive AD showed slight-to-moderate ultraviolet (UV)-A sensitivity (≥30% of normal minimal erythema dose [MED]) and mostly normal or slightly reduced UV-B MEDs (≥80% of normal MED).  

In contrast, 41% of patients had chronic actinic dermatitis, with 93% exhibiting significant UV-B sensitivity, including very low UV-B MEDs (<80% of normal MED) and/or very low UV-A MEDs (<30% of normal MED). No significant differences in age, sex, or skin phototype were found between the groups and serial phototesting revealed changes in photosensitivity status over time in 8 patients.  

Investigators concluded the photosensitivity patterns in AD are heterogeneous and might change over time, emphasizing the need for ongoing monitoring. 

Source: sciencedirect.com/science/article/pii/S0190962224027105#sec1