Delayed contact hypersensitivity to non-steroidal anti-inflammatory drugs

Several non-steroidal anti-inflammatory drugs (NSAIDs) are available for topical treatment of acute soft tissue trauma or degenerative musculoskeletal disorders; the NSAID bufexamac is mainly used for therapy of chronic inflammatory skin diseases. In order to assess the occurrence of contact allergy to NSAIDs in 371 consecutive patients presenting for diagnosis of presumed contact allergy, patch tests were performed with a standard series and additionally with a series of NSAIDs, comprising acetylsalicylic acid, bufexamac, diclofenac, etofenamate, felbinac, flufenamic acid, ibuprofen, indomethacin, and piroxicam. 17 individuals (4.6%) exhibited delayed hypersensitivity to one of the NSAID preparations: 12 patients (3.2%) had patch test reactions to bufexamac, 2 (0.5%) to etofenamate, 2 (0.5%) to indomethacin, and 1 patient (0.3%) to flufenamic acid. These patch test results corresponded well to the individual history in 11 individuals (including 10 patients with reactions to bufexamac), and in 2 patients the clinical relevance of the reactions was probable. In view of the high frequency of allergic contact reactions to bufexamac, we propose to test this drug particularly in patients with atopic eczema or other chronic eczematous diseases.