What is persistent light reactivity? | Fig. 17.3 Actinic reticuloid. Elderly man with chronic, highly pruritic photosensitivity with erythema, scale, pigmentary changes, and lichenification of the skin. (Courtesy of the Fitzsimons Army Medical Center teaching files.) | In persistent light reactivity, photodermatitis believed to be triggered by topical or systemic drugs persists long after the presumed causative agent has been discontinued. These unfortunate patients may be sensitive to a broad range of light, even visible light, and patients may be totally incapacitated by this disease. Chronic actinic dermatitis and actinic reticuloid are related diseases involving persistent and severe photodermatitis and occur primarily in older men (Fig. 17-3). Some believe that the primary event in these conditions is a photocontact dermatitis (photoallergic dermatitis) which persists due to chronic low-grade exposure, and in rare cases, even progressing to an “antigendriven” form of mycosis fungoides, though this is controversial. |