Unit and Laboratory of Occupational and Environmental Dermatology, Catholic University of Louvain, Brussels, Belgium.
The authors describe two cases of allergic contact dermatitis to colophony included in the formulation of flexible collodion BP, the vehicle of a wart paint. Patch and repeated open application tests confirmed absence of contact allergy to other constituents. The patients were known to be allergic to various adhesive plasters. The use of flexible collodion USP, which does not contain colophony, is highly advisable whenever possible.