Baker's Asthma Due to Xylanase and Cellulase Without Sensitization to Alpha-amylase and Only Weak Sensitization to Flour

Background: The baking additives xylanase and cellulase were described as baking additives causing baker's asthma. It is not known whether monosensitization to these enzymes may occur.

Methods: We present a case report of a baker with work-related asthma evaluated by skin prick test (SPT), enzyme-linked immunosorbent assay (EAST), immunoblot, EAST and immunoblot inhibition, and specific bronchial challenge. Fungal xylanase and alpha-amylase were measured by two-site enzyme immunoassays in products used by the patient at work.

Results: Allergy to xylanase and cellulase was demonstrated by SPT, EAST, immunoblot and specific bronchial challenge (for xylanase only). No sensitization to alpha-amylase could be demonstrated, but there was a weak flour allergy as documented by EAST and immunoblot and a positive occupational-type challenge with high concentrations of rye flour. Four baking additives contained measurable amounts of fungal alpha-amylase and xylanase, without a correlation between these enzymes.

Conclusions: We conclude that occupational asthma due to the baking additives xylanase and cellulase may occur without concomitant sensitization to alpha-amylase and only weak sensitization to flour.