ABSTRACT
Drugs that have caused contact allergy/allergic contact dermatitis from topical application, but are not discussed in a separate monograph (chapter), are shown in table 3.228.1 Most are ‘historical’ allergens, that are currently not in use anymore. Various sulfonamides such as sulfanilamide (Chapter 3.323), sulfapyridine, sulfathiazole, and sulfadiazine were used on a large scale during and after the second world war on wounds and to treat cutaneous infections, but they caused many cases of sensitization and the topical use of most was gradually abandoned in many countries (23,24). Nevertheless, in Bari, Italy, in the period 1968-1977, 8.2% of 3758 consecutive patients still reacted to ‘sulfonamide’ 5% pet., although the frequency steeply dropped to 0.2% in the following years 1978-1983 (21). Some sulfonamides (notably sulfanilamide) also caused photosensitization; most patients recovered but some developed persistent light reactions (22). Sulfonamide is stated to have cause erythema multiforme-like allergic contact dermatitis (25).
