Photosensitivity status in atopic dermatitis may change over time

Light sensitivity patterns vary in patients with atopic dermatitis (AD), reports a Scotland study, noting the significance of follow-up assessments because of potential shifts in disease spectrum over time.

In this retrospective analysis, a team of investigators examined the outcomes in 139 patients with AD (mean age 42.6 years, 61.9 percent men) referred for photodiagnostic testing and established diagnostic criteria for photosensitivity in AD. They reviewed the clinical and photodiagnostic data, classifying photosensitivity into photoexacerbated AD, photosensitive AD, and chronic actinic dermatitis.

Overall, 51.1 percent of patients with photoexacerbated AD had normal monochromator phototesting, while 7.9 percent of those with photosensitive AD demonstrated slight-to-moderate ultraviolet (UV)-A sensitivity (≥30 percent of normal minimal erythema dose [MED]) and mostly normal or slightly reduced UV-B MEDs (≥80 percent of normal MED).

On the other hand, chronic actinic dermatitis was found in 41 percent of patients, of which 93 percent had significant UV-B sensitivity, with very low UV-B MEDs (<80 percent of normal MED) and/or very low UV-A MEDs (<30 percent of normal MED).

There were no significant between-group differences seen in age, sex, or skin phototype. In addition, changes in photosensitivity status over time were observed in eight patients via serial phototesting.

This study was limited by its small sample size and retrospective design.