There is an increasing incidence of contact urticaria (CU) and systemic reactions to rubber products. Thirty-one patients are presented: most were atopic (20/31) and women (26/31); 71% worked in the medical field; 32.2% (10/31) showed signs of hand dermatitis. In 28 patients (90.3%), rub and/or prick tests with liquid latex in different dilutions and with latex gloves led to an immediate type of positive reaction. The allergen(s) appear in part to be water soluble: 20 of 28 patients (71.4%) revealed positive test reactions to an aqueous glove extract. In two patients, urticarial test reactions to tetramethylthiuram disulfide (TMTD), mercapto mix, and p-phenylenediamine (PPD mix) were considered as possible contributing factors of CU. Cornstarch was negative in all patients (scratch). Sixteen of 27 sera (59.2%) showed radioallergosorbent (RAST) class 0 using latex allergen disks. Sodium dodecyl sulfate-polyacoyl-amide (SDS-PAGE) determined protein bands of less than or equal to 14 kD (not allergen specific) and approx 28 kD. The Western blot detected the 28 kD protein as allergen in the sera of three patients. Isoelectric focusing (IEF) proved no protein bands. Immunoprinting performed with sera of five patients presented allergen bands in a pH range between 3.8 and 4.55. This shows the radio staining (immunoprint) is more sensitive than is the Coomassie blue staining. Although three sera showed RAST class 0, immunoblotting detected allergen bands. In this case the immunoblot appears to be more sensitive than the RAST. A cross reactivity between latex and banana could not be established. Alternative gloves are Neolon (neoprene) or Elastyren (styrene-butadiene polymer).