Allergic contact dermatitis from formaldehyde in a liquid soap.

A case is reported of a 74-year-old white man who developed generalized allergic contact dermatitis from formaldehyde present in a liquid soap. The patient had a 2+ positive patch test reaction to formaldehyde, which was present as a preservative in the soap at 0.1% concentration. His dermatitis cleared when he switched to a nonformaldehyde-containing bar soap. The cause of the contact dermatitis was covert to both physician and patient before patch testing. Since registration with the Food and Drug Administration of formaldehyde-containing soaps is voluntary, it is likely that there are more soaps on the market than the six registered as of June 1988.