[Sensitization to chymopapain in patients treated with chemonucleolysis]

Chemonucleolysis (intradisk administration of chymopapain) is a procedure to treat intervertebral disk hernia. Recently, its use has been questioned due to the development of anaphylactic reactions in patients sensitized to chymopapain. The prevalence of sensitization to chymopapain has been evaluated before and after chemonucleolysis, and the possibility to establish risk groups through the allergy history has been assessed.

104 consecutive patients who were candidates to chemonucleolysis were evaluated with an allergy questionnaire, cutaneous tests to aeroallergens and to chymopapain, and chymopapain-specific IgE. The two latter tests were repeated one month after chemonucleolysis.

Only 2 patients (1.9%) showed evidence of chymopapain sensitization before the procedure. Sixteen patients (16%) were sensitized after chemonucleolysis. None of the possible risk factors evaluated in the allergy questionnaire (atopy, drug allergy, papaya occupational exposure or use of additives, cosmetics or drugs containing papaine) were significantly related with the risk of sensitization to chymopapain.

The prevalence of chymopapain sensitization in the study group was low. The allergy questionnaire (atopy, drug allergy, use of papaya, occupational history did not identify sensitized patients. Cutaneous tests and specific IgE are the best method to detect chymopapain sensitization. The remarkable rate of sensitization after chemonucleolysis may partially limit the usefulness of the procedure.