Man suffers chemical burn that lasted months after squeezing limes

If Margaritaville were a real place, it would be wise to keep a few dermatologists on staff. A 40-year-old man recently visited an allergy clinic in Texas with a severe, burning rash on both hands that had appeared two days earlier. Within days the skin blistered; weeks later it darkened and scaled. Only after several months did his hands return to normal.

The Culprit: Lime Juice and Sunlight

The trigger was a common but under-recognized hazard of food preparation. Just before the rash developed, the man had squeezed a dozen limes by hand and then attended an outdoor soccer game without sunscreen. His physicians diagnosed phytophotodermatitis, a condition described in a case report published Wednesday in the New England Journal of Medicine.

What Is Phytophotodermatitis?

The reaction occurs when plant-derived compounds (phyto) interact with ultraviolet light (photo) to produce a painful, blistering dermatitis. The key chemicals are furocoumarins, found in celery, carrots, parsley, fennel, parsnips, limes, lemons, grapefruit, bitter oranges, and sweet oranges. Once absorbed into skin cells, these molecules become activated by UV exposure, forming bonds with DNA that halt cell replication, trigger inflammation, and cause the characteristic burn-like injury.

A Centuries-Old Phenomenon

Although unfamiliar to many home cooks, phytophotodermatitis has been recognized for centuries. In ancient Egypt, people with vitiligo applied juice from false bishop’s weed (Ammi majus) and exposed their skin to sunlight to stimulate pigmentation. The plant contains psoralen derivatives that darken skin on UV contact, yet excessive amounts can just as easily provoke severe phytophotodermatitis.

Treatment and Recovery

Management focuses on reducing inflammation. The patient received a topical steroid cream and lotion; full healing still required several months. Awareness of the risk, however, allows simple prevention: wearing gloves while handling citrus or applying sunscreen afterward can spare others the same prolonged discomfort.