Contact dermatitis from Larrea (creosote bush).

Six men suffering from acute dermatitis had positive patch tests to Larrea (creosote bush). The lesions preferentially involved sun-exposed sites, simulating a photodermatitis, but also were on the legs and scrotum. Our findings were more consistent with contact allergy than with a primary irritant or a phototoxic response. The patch tests were also positive to Zuccagnia punctata. In two cases the exposure to the creosote bush occurred as a result of casual occupations, in two because of household remedies (moist compresses and baths), and in the other two as a result of burning the bush and resorting to household remedies. Attention should be drawn to this contact dermatitis because the creosote bush grows abundantly all over the American continent.