The Exchange

Commentary and Observations from
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Phytophotodermatitis: Skin Rash With a Twist

Phytophotodermatitis: Skin Rash With a Twist

Phytophotodermatitis, also known as the "margarita rash," is a commonly seen condition in the spring and summer months or any time a patient has had exposure to bright, sunny days. It always surprises the patient when you take their history and ask if they have been in the sun while drinking or eating anything with limes, lemons, or other fruits. Most of the time they will report a recent beach trip or day spent by the pool, where they were able to partake in refreshing margaritas or beer with a lime twist!

Phytophotodermatitis is a cutaneous, phototoxic, inflammatory eruption resulting from contact with light-sensitizing botanical substances, also known as furanocoumarins, and long-wave ultraviolet A (UV-A; 320-380 nm) radiation. This phototoxic eruption is entirely independent of the immune system, so it can occur in any individual, and prior sensitization is not required. The most common plants that are reported to cause this reaction are lemons, limes, oranges, parsley, parsnips, carrots, celery, figs, and a few others.

After exposure, pruritus, erythema, and/or blisters occur within 24 hours and resolve around the 72-hour mark, leaving hyperpigmented patches. Bizarre inflammatory patterns and linear streaks of hyperpigmentation are key clues to diagnosing phytophotodermatitis. Treatment consists of topical steroids twice a day for up to 2 weeks and sun protection. The pigmentation will fade; however, it is important to set expectations that its resolution may take months.


Filed under: Dermatology

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