Occupational asthma caused by peracetic acid-hydrogen peroxide mixture

Background Healthcare practice in the UK has moved away from using aldehyde disinfectants for the decontamination of endoscopes, in part due to the risk of respiratory sensitization. Peracetic acid (PAA) in combination with hydrogen peroxide (HP) is a commonly used alternative. Aim We describe a case of occupational asthma (OA) diagnosed at our specialist occupational lung disease clinic and caused by occupational exposure to PAA-HP mixture, used as a disinfectant in an endoscope washer-disinfector machine. Case report A 48-year-old man employed as a mycologist and environmental microbiologist at a Birmingham city hospital, UK, presented following an acute exposure to PAA-HP mixture causing lacrimation, burning optic pain and headache. He had also experienced symptoms suggestive of OA for the preceding 10 months, and the diagnosis was confirmed through OASYS analysis of serial peak expiratory flow measurements. He had been exposed to PAA-HP mixture whilst working in the endoscopy department for 12 months prior to the acute episode, and a subsequent specific inhalation challenge test was positive with a late asthmatic response to PAA-HP mixture. Conclusion This case provides evidence for a sensitization mechanism in OA caused by PAA-HP mixture.