Contraindications of Lime - aka Mexican Beer Dermatitis

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Lime juice, peel and oil are generally considered safe to consume in food amounts, and few reported side effects, including photosensitivity, headaches, diarrhea and dental effects, have been noted in case reports and clinical studies. Lime has GRAS (generally recognized as safe) status for use in foods in the United States.

Dr. Scott Flugman, of Huntington Hospital in New York, reports in the Archives of Dermatology that a substance in lime juice, if left on the skin in the sun, can cause the skin to become discolored, as if stung by jellyfish or poison ivy. And the marks can last for months. The substance, called psoralen, makes the skin more sensitive to the effects of a wavelength of ultraviolet light known as UV-A. Psoralen is commonly used as treatment for skin issues such as psoriasis and eczema.

Skin discoloration due to psoralen is common in drinkers of Mexican beers, particularly Corona, which are typically served with a lime slice wedged into the top of the bottle. The drinker then shoves the lime into the bottle and holds his or her thumb over the bottle's mouth while turning the bottle over to mix in the juice. If the drinker isn't careful, however, the beer's carbonation can spray lime juice and beer all over his or her skin. Add a sunny environment like a beach or swimming pool and UV-A rays from the sun can quickly cause blistering, rashes and temporary discoloration.

Applicable parts of lime in skin care products are the peel, fruit, and juice. Lime pericarp, or the lime fruit, including skin and pulp, contains an essential oil (7%), whose main components are citral, limonene, β-pinene, and fenchone (up to 15%). Lime oil has also been documented to contain oxypeucedanin, a phototoxic compound. Further aromatic compounds are terpineol, bisabolene and other terpenoids. The fresh juice of acid limes averages approximately 7.7% citric acid and 0.3% invert sugar. The peel, or rind, contains a volatile oil including the terpene limonene and citral. 

Lime is a popular ingredient in summer skin care products. Distilled lime oil may be non-irritating, non-sensitizing and non-phototoxic to human skin, but expressed lime oil and lime peel may cause phototoxic skin reactions. It is important to recognize the limitations of usage, especially in products intended for use in the sunny months of summer. Alternatives such as Distilled Lime Oil, Lime Peel Powder or Fragrance Oils designed to mimic the scent of limes are widely available and help reduce the risk of skin discoloration and photosensitivity. 

Allison B. Kontur

www.BathBodySupply.com