Occupational asthma secondary to enzymes used in cheese production

Occupational asthma (OA) accounts for 5-10% of all asthma in adults. Although OA secondary to enzymes has been reported, it is rare in the context of food preparation, In the cheese production industry, multiple powdered enzymes are used to soften and flavor cheese. Work-related asthma secondary to enzymes used in this manner has not been previously reported. We present two cases of OA after exposure to airborne enzyme powders used in cheese production. Both patients were adult women without histories of asthma who worked in a facility that used fungal and pancreatic-based enzymes to soften and flavor cheese. Both developed asthma symptoms within 1 year of employment and experienced relief of symptoms away from work. One patient had occupational rhinitis. Each underwent allergy skin testing, chest radiograph, pulmonary function testing, and methacholine challenge. Both patients had markedly positive skin tests to multiple enzyme antigens used at work. Spirometry, lung volumes, and chest radiographs were normal for both patients when they were asymptomatic and had implemented avoidance measures. Methacholine challenge was positive in one patient (PC20 = 0.13 mg/mL). Both workers took appropriate respiratory protection measures during powder exposure and their symptoms improved. Enzyme powder used in cheese production is a trigger for OA.