Phytophotodermatitis: Bulla formation and hyperpigmentation during spring break

Abstract

Phytophotodermatitis is a phototoxic dermatologic reaction that occurs with exposure to ultraviolet light after contact with certain plant chemicals. Recognition is vital to proper management and avoidance of unnecessary distress for patients. Sun-sensitizing compounds, known as furocoumarins, are found in many plants (limes, celery, and natural grasses) and are excited by ultraviolet A (UVA) irradiation. UVA irradiation induces covalent linkages of nuclear DNA resulting in cutaneous photosensitivity and vesicular skin damage while increasing melanin production. Delayed erythema, hyperpigmentation, and vesicle or bullae formation are hallmarks. Literature review reveals most cases occur during or after vacation in a sunny destination with exposure to citrus fruit or in children playing outdoors in the summer when furocoumarins are abundant. Hyperpigmented lesions typically appear on the hands or around the mouth. Overall incidence is unknown and there appears to be no predilection for race, although typically more easily recognized in the fair skinned. Of concern are the many cases where misdiagnosis of child abuse has occurred with unnecessary legal action taken and emotional distress for innocent families. Phytophotodermatitis is relatively common and easily diagnosed with awareness and a careful history. Accurate diagnosis avoids unnecessary concern by patients and potential misdiagnosis of abuse. Consider phytophotodermatitis when hyperpigmentation in bizarre streaks on sun-exposed areas with vesicles in a nondermatomal distribution is present. Presented is an illustrative case.