Phototoxicity from rue when used as a mosquito repellent

Ruta graveolens (rue, witchbane) is used as a mosquito repellant. Pick the flowering plant, crush it, and rub the oils over your skin.

But when the psoralens from rue come in contact with human skin and are exposed to ultraviolet A light, a photoirritant reaction can occur.

This case report published in the journal Dermatitis and on Medscape, describes a group of people on an outing that used rue in this way. Within a day, some developed purple-red patches on various areas of their bodies where the rue was rubbed.

The description of the reaction and the relation between sun exposure time and extent of the reaction makes this a very interesting article to read.

More background on rue is here.

8/7/07 21:15 JR