[Chymopapain allergy. Diagnostic value of a skin test before and after chemonucleolysis]

Chemonucleolysis with Chymopapain (Chymodiactin, Disease) bears the risk of unpredictable anaphylactic reactions. The rate of anaphylaxis is reported to be between 0.35 and 1.5%. Serological in vitro tests such as RAST (Radio Allergo Sorbent Test) or ChymoFAST (Fluorescent Allergo Sorbent Test) are used to determine increased specific IgE antibody titres against chymopapain in patients submitted to chemonucleolysis for lumbar disc disease. Alternatively skin prick tests have also been applied in clinical trials. A skin prick test including Discase, Chymodiactin and Solutrast 250 M, which is a radiopaque dye used for discography, has been performed in a total of 208 patients. One-hundred and seventy-seven patients were tested before, 31 patients were tested after chemonucleolysis with chymopapain. From the group tested before chemonucleolysis, 2.3-3.5% had positive skin testes. After chemonucleolysis, the overall allergy rate to chymopapain increased to 41.9%. Positive skin reactions seem to be time-dependent: Between the 3rd and 12th week after chemonucleolysis more than 70% of the patients had positive skin tests. There was no correlation between a history of previous allergy and the skin test result. Patients with positive skin tests should be excluded from chemonucleolysis. This procedure increases the safety for patients submitted to chemonucleolysis. No anaphylactic reaction has been observed hitherto in nearly 350 patients who were treated with the intradiscal injection of chymopapain following a negative skin prick test.