Comparison of patch test results in two adjacent areas of England. II. Medicaments.

A 3-year study of patch test reactions to the Standard European Battery (S. E. B.) has been carried out in two adjacent areas of South-east England with the same climatic and cultural background. The source of materials and method of testing were identical; all observers have worked together in the same Contact Dermatitis Clinic and the interpretation of reactions can therefore be considered to be consistent. The main differences between the two areas lay in the pattern of employment and in local prescribing habits. Only the second aspect is considered here. Seven allergens--lanolin, neomycin, parabens, iodochlorhydroxyquinoline, ethylene diamine, caine 'mix' and chlorocresol--accounted for approximately 30% of all positive patch test reactions. 'Medicament sensitivity' correlated well with the known prescribing habits of both regions. Certain sites were shown to be especially important in the pathogenesis of medicament contact sensitivity.