Library: Limes and contact dermatitis
Limes are a delightful citrus food that have become increasingly popular. Lime juice and lime peel are found in drinks, jams, jellies and marmalades, sauces and marinades, and cakes and deserts. Elements of lime are used in processed foods as flavourings and the oil is sometimes used in herbal preparations and cosmetics. Chunks or slices of lime are frequently served with drinks.
Like all foods, lime can cause problems for some individuals. Contact reactions to lime generally result in dermatitis or urticaria – some examples are given below.
A six year old boys hands became red, swollen and painful. The cause was found to be lime juice. The boy’s hands had been immersed in lime juice whilst he had been helping to make limeade. 
In one case, a bartender developed hand dermatitis that was identified as being an allergic contact sensitivity to lime peel. 
A substance called psoralen in lime juice, if left on the skin in the sun, can cause the skin to become discoloured, as if by poison ivy or a jellyfish sting -- and the marks can last for months. Some Mexican beers are typically served with a lime slice wedged in the top of the bottle. The drinker pushes the lime into the bottle and holds his thumb over the bottle's mouth while turning the bottle over to mix in the juice. If the drinker is not careful, the beer's carbonation can spray lime juice onto his skin. 
A day camp in Maryland had a large number of children experience skin eruptions consistent with phototoxic dermatitis on their hands, wrists, and forearms. It was found that 97 (16%) of 622 children, seven (7%) of 104 counsellors were affected. Initially no common link could be found but an examination of the type of activities the individuals affected had been involved with identified the making of pomander balls as the likely candidate. In making pomander balls, children punctured the skin of limes (the principal component) with scissors, releasing oils known to contain photoreactive furocoumarin (psoralen) compounds -these compounds evidently coated the children's skin and, upon exposure to the sun, caused a phototoxic dermatitis. 
“Gin and tonic dermatitis" can occur after someone squeezes limes in gin and tonics and then gets sun exposure. Dr DeLeo states that there are reports of children being brought into paediatric emergency rooms with handprints on their bodies leading to the parents being suspected of child abuse. Yet, the hand marks were produced by parents squeezing limes during a beach trip, then picking up the child and unwittingly applying lime juice to the child's skin. The photoirritant reaction is a delayed response that peaks several days later. "You could do this on a weekend and not see this response until Tuesday or Wednesday. Most people wouldn't connect the response" to squeezing limes a few days earlier, he said. 
Thomson et al present the case of a fifty-two year old woman who had an eczematous rash at the side of her mouth and lips. She had been sucking the Lime from her gin and tonic for up to 1 minute after finishing her drink. 
1. Wagner AM, Wu JJ, Hansen RC, Nigg HN, Beiere RC. Bullous phytophotodermatitis associated with high natural concentrations of furanocoumarins in limes. Am J Contact Dermat. 2002 Mar;13(1):10-4.
2. Swerdlin A, Rainey D, Storrs FJ. Fragrance mix reactions and lime allergic contact dermatitis. Dermatitis. 2010 Aug;21(4):214-6.
3. Flugman SL. Mexican beer dermatitis: a unique variant of lime phytophotodermatitis attributable to contemporary beer-drinking practices. Arch Dermatol. 2010 Oct;146(10):1194-5.
4. Gross TP, Ratner L, de Rodriguez O, Farrell KP, Israel E. An outbreak of phototoxic dermatitis due to limes. Am J Epidemiol. 1987 Mar;125(3):509-14.
5. Sherry Boschert 'Gin and tonic dermatitis' traced to limes plus sun exposure http://findarticles.com/p/articles/mi_hb4365/is_19_39/ai_n29392491/
6. Thomson MA, Preston PW, Prais L, Foulds IS. Lime dermatitis from gin and tonic with a twist of lime. Contact Dermatitis. 2007 Feb;56(2):114-5.