Occupational asthma in a mycologist

Abstract

Case study: A 48 year-old man presented to occupational lung disease clinic following an acute exposure to vapourised peracetic acid through leakage from an automated endoscope processing machine. This occurred during sampling in his role as a mycologist and environmental scientist at a hospital in Birmingham, UK. He had developed work-related asthma symptoms 10 months before this incident, and had been performing environmental sampling in endoscopy at the hospital for 9 years. He suffered obstructive sleep apnoea, hyperlipidaemia and was an ex-smoker with 15 pack year history. At diagnosis clinical examination, chest radiograph, thoracic computed tomography (CT) scan, methacholine reactivity and spirometry were normal. Initially he continued his job with heightened surveillance but experienced work-related asthma symptoms, including after low-level exposure to peracetic acid when sampling in endoscopy. OASYS analysis of serial peak expiratory flow measurements revealed occupational asthma (OA; OASYS score=3.3, ABC=19). He underwent specific inhalation challenge to actichlor (normal), surfactant detergent (immediate irritant response) and then peracetic acid with a significant fall in FEV1 at 4 hours after 120 minute exposure (Figure). Conclusion: We present a case of OA with a late, specific airway response to peractic acid, used as a substitute for glutaraldehyde for endoscope disinfection. This has been described only once previously1 and therefore adds weight to the evidence for an immunological mechanism. 1Cristofari-Marquand et al. J Occup Health 2007;49:155-8. Figure: Specific inhalation challenge to peracetic acid showing late asthmatic response with maximal fall in FEV1 of 21% from a baseline of 3.35L to 2.66L.