Chronic Actinic Dermatitis: A Review
Artz CE, Farmer CM, and Lim HW. Chronic Actinic Dermatitis: A Review. Current Dermatology Reports 2019; 8(3):104-109.
Current Dermatology Reports
Purpose of Review: To update readers on the current understandings of chronic actinic dermatitis (CAD) in regard to epidemiology, clinical findings, pathophysiology, treatment, and prognosis. Recent Findings: CAD is classically thought to be primarily a disease of elderly Caucasian males, though recent evidence suggests that in skin of color, the disease manifests more often in younger females. Recent studies suggest the pathogenesis of CAD involves a type-IV hypersensitivity reaction, similar to allergic contact dermatitis. There is also evidence of resistance to UV-induced immunosuppression in these patients, similar to polymorphous light eruption (PMLE). Furthermore, a lower CD4/CD8 ratio on flow cytometry in CAD patients has been correlated with increased tissue burden of disease. Photoprotection remains a mainstay of treatment, though recent evidence suggests potential efficacy of tofacitinib or short courses of narrowband UVB phototherapy as treatment options. Summary: CAD is an immunologically mediated photodermatosis characterized by pruritic eczematous lesions of sun-exposed areas, most commonly seen in older Caucasian males. While the pathogenesis of the condition is not fully understood, a type-IV hypersensitivity reaction to UV-induced neoantigens is thought to play a role. Photoprotection remains the mainstay of treatment, though adjunctive treatments are rapidly emerging. Though considered a chronic condition, CAD tends to improve over time.