Phytophotodermatitis: An under-recognized diagnostic pitfall in chemical burns

Phytophotodermatitis is a rare and poorly recognized cause of chemical burns. It consists of a non-immunologic cutaneous reaction caused by exposure to plants containing photosensitizing substances, followed by ultraviolet (UV) radiation exposure. The clinical manifestations resemble those of second-degree burns. Numerous differential diagnoses are possible. Diagnosis is based on a detailed history, highlighting the characteristic temporal sequence of contact with a phototoxic substance followed by UV exposure. Treatment is mainly symptomatic.

This study aims to report five cases of phytophotodermatitis and to provide an overview of its diagnosis and management.

We report five cases managed in the Plastic Surgery Department at Montpellier University Hospital between April 2015 and May 2024. Data collected included demographic characteristics, time to diagnosis, aetiology, duration of management and healing, potential need for surgical intervention, and long-term complications.

The implicated plant species belonged to the families Apiaceae (2 cases), Moraceae (1 case), and Rutaceae (2 cases). The mean time to symptom onset was 28.8h. Cutaneous manifestations included erythema (5 cases), vesicles (2 cases), and bullae (3 cases). All patients received immediate irrigation of the affected areas with water, followed by topical corticosteroid therapy. None of the patients required surgical management to achieve re-epithelialization. Post-inflammatory hyperpigmentation persisted as a sequela in one case.

A thorough history is essential to identify the characteristic temporal sequence and to initiate treatment promptly. Management primarily relies on analgesics and topical corticosteroids dressings, with rapid healing in most cases. Long-term sequelae may include persistent cutaneous hyperpigmentation for several years.