Contact sensitivity to aluminium in a patient hyposensitized with aluminium precipitated grass pollen.

Standard patch testing of a patient with eczema revealed positive reactions to the aluminium discs used for testing. Patch tests with various aluminium allergens were positive in the patient and negative in 53 controls. The patient was having hyposensitization for hay-fever with an aluminium precipitated allergen. Intradermal testing with aluminium was positive in the patient and negative in nine controls. The eczema disappeared when hyposensitization was discontinued. The possibility of primary sensitization by the hyposensitization procedure is discussed.