Berloque Dermatitis

An 8-year-old boy was taken to his physician because of a rash around his mouth. After spending the day at the beach with his family, his lips had become red, itchy, and swollen (A). His sister had a similar, although milder, condition. Both children had been sucking on limes while at the beach. One week later, the boy experienced the chapped lips, patchy perioral erythema, swelling, and blisters (pictured here).

The diagnosis was berloque dermatitis, a pigmented phytophotodermatitis that can result from combined exposure to sunlight and substances containing the plant psoralens known as furocoumarins (eg, lime and lemon rind, oil of bergamot). During the acute stage, topical corticosteroids and emollients are applied to the rash. After this phase is past, the hyper-pigmentation is best treated with a hydrophilic ointment containing tretinoin, 0.1%; hydroquinone, 5%, and dexamethasone, 0.1%. The patient should also use a sunscreen. When the superficial hyperpigmentation is treated promptly, it often clears in 1 to 2 weeks. If left untreated, it may persist for months.

Berloque dermatitis can also be caused by the combined exposure to sunlight and perfume containing psoralens (B). The hyperpigmentation can persist indefinitely, even after use of the perfume is discontinued and sunscreen is applied daily. Laser treatment may be of some help.