Cobalt sensitization and dermatitis: considerations for the clinician.

This clinical review article presents clinical and scientific data on cobalt sensitization and dermatitis. It is concluded that cobalt despite being a strong sensitizer and a prevalent contact allergen to come up on patch testing should be regarded as a very complex metal to test with. Exposure data together with clinical data from metal workers heavily exposed to cobalt suggest that patch-test reactions are sometimes false positive and that patch testers should carefully evaluate their clinical relevance.