Skin Prick Tests with Solutions of Acid Anhydrides in Acetone

Abstract

Various low molecular acid anhydrides can act as haptens and induce type I allergies. Immunoglobulin E can be detected by radioallergosorbent test (RAST) with the protein conjugates of the respective anhydrides, which are commercially available for some substances. Being almost nonsoluble in water, these species cannot be applied in a skin prick test as a water solution. We will introduce a practicable skin prick test using acetonic solutions of the haptens. 136 persons were tested with acetone for negative control and histamine for positive control. Tests were carried out with 1 and 5% acetonic solutions of phthalic anhydride (PA). The RASTs with conjugates of the PA were performed with 111 subjects who had been exposed to acid anhydrides and with 5 people who possibly had been exposed. In 14 cases, when immediate-type allergy was suspected clinically, a test was performed in addition to the respective anhydride used at the workplace. In order to avoid unspecific histamine liberation, we tested 20 volunteer control persons who had not been occupationally exposed to acid anhydrides. In the prick test performed with acetonic PA solutions, 10 of the occupationally exposed subjects, who had also had a positive result in the RAST with protein conjugates of the PA, showed positive skin reactions, and in 2 further cases, in which the skin reaction was positive, the results of the RAST were just below the limit of a positive evaluation. The skin reaction was positive in 4 cases, in spite of a negative RAST result, while the prick test was reported to be negative in 3 cases although the RAST results were considered to be positive.(ABSTRACT TRUNCATED AT 250 WORDS)