[Allergic contact dermatitis to diethylthiourea in a neoprene wader]. / Dermatitis alérgica de contacto a dietiltiourea por un traje de pesca de neopreno.

Diethylthiourea, like other thioureas, is often used by the rubber industry and in the manufacture of neoprene. We present a patient who suffered allergic contact dermatitis to diethylthiourea in a neoprene wader and who required admission to hospital and systemic treatment. We review the literature on allergy to diethylthiourea. Thioureas are not included in the standard GEIDAC (Spanish Contact Dermatitis Research Group) battery of patch tests. In these cases, it is necessary to use a special battery of rubber allergens, which includes thiourea compounds, for diagnosis of the disease and to ensure that cases of contact allergic dermatitis to thioureas do not go undiagnosed.

Fixed drug eruption from piroxicam.

The pathogenetic mechanism of fixed drug eruption (FDE) is still unknown. One of the most common causes of FDE is the use of nonsteroidal antiinflammatory drugs (NSAIDs). Oxicams are in the NSAID group and piroxicam is one of the most used of these drugs. FDE caused by piroxicam is rare but a few cases have been reported. Patch tests are useful for diagnosing some cases of FDE; they give variable results on previously affected skin while no reaction appears on unaffected skin. Some cases of cross-sensitivity among piroxicam and other substances have been reported. We report two new cases of FDE due to piroxicam with negative patch test on normal skin and positive results on affected skin.