Isocyanate HDI allergy test will be useful to establish the diagnosis of an allergic disease and to define the allergens responsible for eliciting signs and symptoms. Isocyanates are widely used in the production of polyurethane plastics, glues and paints. Individuals at risk are polyurethane foam makers, upholsterers, spray painters, wire coating workers, plastic molders, rubber workers, fabric coaters, metal rod coaters, truck body insulators and persons applying artificial turf and others. Isocyanate HDI allergy test will be useful to identify allergens which may be responsible for allergic disease and/or anaphylactic episode, to confirm sensitization to particular allergens prior to beginning immunotherapy, and to investigate the specificity of allergic reactions to insect venom allergens, drugs, or chemical allergens.