Margarita Dermatitis Revisited: A Case Report and Literature Review of Lime-Associated Phytophotodermatitis.

Phytophotodermatitis is a phototoxic skin reaction that occurs after topical contact with certain plant substances followed by exposure of the affected skin area to the sun. A unique type of phytophotodermatitis is margarita dermatitis. This results from contact with either lime peel or lime juice, or both, with the skin and subsequent exposure to ultraviolet A radiation to the lime-contacted skin. Other variants of lime-associated, alcoholic beverage-related phytophotodermatitis are mojito dermatitis and Mexican beer dermatitis. Lime-induced phytophotodermatitis typically results in the acute onset of symptoms and lesions, such as painful and occasionally pruritic erythema and blisters, after the skin that has been in contact with the lime is exposed to the sun. As the initial lesions resolve, postinflammatory hyperpigmentation occurs, which often eventually improves or completely resolves. In many circumstances, the patient is unaware that not only the contact with lime and the skin but also the subsequent sun exposure were related to the development of their new cutaneous dermatosis; indeed, the clinician evaluating these individuals needs to have a high level of suspicion that the patient's new lesions may be a phytophotodermatitis. Often, the person with acute manifestations or chronic hyperpigmentation associated with lime-related phytophotodermatitis is initially diagnosed with an incorrect condition by the medical personnel who are performing the evaluation. The differential diagnosis can include primary bullous conditions, atypical bruising or purpura, other types of dermatitis, infections, drug reactions, pigmentary disorders, and trauma such as child abuse when a pediatric patient presents for assessment. Less commonly, lime-related phytophotodermatitis can present with asymptomatic delayed hyperpigmentation. A 28-year-old man is described whose margarita dermatitis presented with asymptomatic pigmentation on his hands three days after exposure to limes and sunlight. Including this patient, lime-associated asymptomatic hyperpigmentation phytophotodermatitis has been reported in 14 individuals. The pigment that was most common on the dorsal hands (11 patients) and acquired while preparing a beverage or meal for consumption that included lime was the most common exposure to the lime; the pigment occurred on the back in the remaining three patients. The pigment appeared from two days up to three to seven weeks (median, seven days) after exposure to the lime.