This 4 year old girl developed red patches with central blisters on her right arm and shoulder while on a winter beach vacation in the Carribbean with her parents. Her mother noted that she was observed to be sucking on limes after she accompanied her father to the bar on the beach. The subsequent exaggerated sunburn with erythema, blistering, and crusting occurs when the topical plant photosensitizer is activated by long wavelength ultraviolet light (UVA) in sunlight. Phytophotodermatitis is the most common topical phototoxic reaction occurring in children and is caused by exposure to plants or plant products containing psoralens. Limes contain over 10 times as much oil of bergamot (containing 5-methoxy psoralen) as other citrus fruits and are the most common offenders.
irregularly shaped hyperpigmented patches with central erythema and healing crusts