phytophotodermatitisIf you are going down south to a Club Med, beware of “Club Med dermatitis.” One of the social events at the vacation club encourages the juxtaposition of certain body parts by requiring participants to pass a lime from one to an other in a “lap to lap, thigh to thigh” fashion.  This can result in a rash, as experienced by one young lady. The rash appeared exactly where the lime had contacted the skin on the thighs.  What happened?  The diagnosis was easy: phytophotodermatitis.  In other words, a skin reaction caused by naturally occurring plant chemicals which become toxic only when activated by ultraviolet light.  This is not an allergic reaction; in other words the immune system is not involved.  Anyone exposed to a sensitizers and ultraviolet light can have a reaction.  As was the case with our vacationer, the raction disappears within a few days.  Indeed, the young lady was quite thankful that she had only experienced a case which has since been referred to as “Club Med dermatitis.”  Some other “lap to lap” transmitted afflictions may not have been so easy to resolve.
Such phytotoxic reactions can actually be traced to furocoumarins, compounds found in limes, as well as in other citrus fruits, parsley, dill, parsnips and chrysanthemums.  Indeed, these furocoumarins are well known to be the cause of “celery handlers’ disease.”  This is a condition which sometimes afflicts produce handlers as well as cashiers and baggers in fruit and vegetable stores.  The problem is usually seen from April to August, when the workers come off their shift and are exposed to sunlight.  The worst rashes develop in people who have handled aging celery; furocoumarins are produced as the plant’s cellular tissues decompose.  But you don’t have to work with vegetables to have a skirmish with furocoumarins.  Many perfumes and colognes contain oil of bergamot which contains the sensitizer 5-methoxypsoralen.  The so-called “sun-rash” that some ladies experience may be a phototoxic reaction to their perfume.
Joe Schwarcz

One response to “Phytophotodermatitis”

  1. Christopher Wisniewski says:

    I find this very interesting. That a substance only when exposed to sunlight becomes toxic. I’ll stay out of the sun after passing through the produce section and take a bath as soon as I get home. Never really liked perfumes and didn’t know why. Now I can cite this article. What other hazards are lurking in our local stores?

Leave a Reply

Your email address will not be published. Required fields are marked *

This blog is kept spam free by WP-SpamFree.

Blog authors are solely responsible for the content of the blogs listed in the directory. Neither the content of these blogs, nor the links to other web sites, are screened, approved, reviewed or endorsed by McGill University. The text and other material on these blogs are the opinion of the specific author and are not statements of advice, opinion, or information of McGill.