Orange and Sunlight: A Recipe for Blisters

Lime disease or phytophotodermatitis is a phototoxic inflammatory cutaneous eruption that occurs when skin is exposed to furanocoumarin-containing plants and sunlight. The presentations range from mild erythema to acute blisters or bullae.1 Common causative plants include lime, lemons, figs, parsnips and celery. The diagnosis is clinical and relies on meticulous review of exposure history, correlating the pattern of skin lesions with area of contact and excluding other causes of photodermatitis. Though the condition is not rare surgeons may encounter such cases and knowledge about the pathogenesis helps in the differential diagnosis.1,2 A 40 year-old man was referred to the Plastic Surgery Unit with an extensive rash involving both arms and legs. It developed over the course of two days, initially started with painful patches of erythema, which later developed into well demarcated, irregularly shaped plaques with clusters of vesicles and bullae (Figures 1 and 2). The distribution of the rash did not follow dermatomes. He was systemically well with no fever or joint pain. The rest of the physical examination was unremarkable. He had no significant past medical or dermatological history and was not on any regular medications. He was out in his garden for quite sometime but did not come in contact with any plants or insects. He had no recent exposure to fragrances, perfumes or chemicals. However, on further questioning about any contact, he remembered that while squeezing oranges inside his house, he had accidentally splashed orange juice onto his hands, arms and legs, which he ignored and did not wash off. He then went straight to the garden afterwards. He realised that the rashes were in the areas the juice had come in contact with his body. Due to the history of exposure to orange juice and sunlight, the diagnosis of Lime disease or phytophotodermatitis was made. The patient was treated with two types of topical paraffin cream (Aquamax cream and Cetraben cream). The condition was explained to him and reassurance given. He was advised sun protection and to avoid photosensitizing agents to prevent future episodes. On follow up 8 days later, the erythema in the area had reduced. Vesicles and bullae had resolved and exfoliation had occurred (Figure 3). There was development of hyperpigmentation, which resolved over several months. Phytophotodermatitis is a phototoxic skin eruption due to contact with furocoumarins (psoralens), a compound found in plants, and subsequent exposure to long wavelength ultraviolet A (UVA) radiation. Common plants that contain furocuramins and found to be associated with phytophotodermatitis include 1. Department of Surgery, Glasgow Royal Infirmary, 84 Castle Street, Glasgow, UK; 2. Department of Plastic Surgery, Wexham Park Hospital, Slough, UK