Cross-reactivity between raw mushroom and molds in a patient with oral allergy syndrome

Oral allergy syndrome, resulting from a cross-reactivity between raw fruits and vegetables and a number of pollens, is well described. However, it has never been associated with mold spore sensitivity and mushrooms. We evaluated a patient with oral allergy symptoms to raw, but not cooked, mushrooms, who also had positive skin testing to molds.

To identify and characterize antigenic cross-reactivity between mushroom and mold spores.

The patient underwent skin prick testing to molds and mushroom. Proteins from raw and cooked mushrooms were extracted and immunoblot/inhibition assays were performed to evaluate for cross-reacting immunoglobulin E antibodies between mushroom and mold extracts to which the patient was sensitive.

The patient had a positive skin prick test result to raw mushroom and four types of molds. The immunoblot assay revealed immunoglobulin E antibodies directed against similar molecular weight proteins in the raw mushroom and 3 of the 4 molds: Alternaria tenuis, Fusarium vasinfectum, and Hormodendrum cladosporioides. These protein bands on protein electrophoresis were absent in the cooked mushrooms. Inhibition immunoblot of the raw mushroom with the three molds indicated total inhibition of the 43- and 67-kD protein bands.

We report the first case of cross-reactivity between mushroom and molds in a patient with oral allergy syndrome to raw mushroom and allergic rhinitis secondary to molds.