Chawapon Luengtongkam¹, Naesinee Chaiear¹, Phanumas Krisorn¹

A 46-year-old male worked as a production line controller inspecting a cooling water system in a PVC pipe production line. While opening the cooling tank lid without wearing personal protective equipment, he was sprayed by a cool mist from the cooling tank. Approximately five minutes afterward, this exposure caused pruritic urticaria on the patient’s arms, back, and face. The patient rinsed his face and arms with warm water, but the pruritic urticaria persisted, eventually leading to collapse. Hypotension was observed by the authors, subsequently diagnosed as anaphylaxis. The patient was transported to a hospital for treatment, which alleviated the symptoms. Later, the authors followed up the patient and reviewed his job history. The patient’s initial symptoms, characterized by urticaria on his arms and back, began in 1996 at the age of 20 and were triggered by cold temperatures, such as bathing with cool water. These symptoms recurred twice a year. Based on this history, it was suspected that exposure to cold temperatures in the workplace might have been a contributing factor to anaphylaxis. According to information provided by the safety officer and supervisor, the patient might have been exposed to chlorodifluoromethane, a refrigerant, at a temperature of –40℃. He was later diagnosed with occupational anaphylaxis associated with cold urticaria, supported by the ACOEM Practice Guideline 2018 and the nine steps for occupational disease diagnosis outlined in the Association of Occupational and Environmental Diseases of Thailand Guideline. The present case highlighted the importance of following safety protocols in the workplace, such as avoiding exposure to cold temperature by adhering to standard operating procedures. When it is necessary to open the cooling tank lid, a face shield, goggles, or respirator must be worn as personal protective equipment.

Received 17 September 2024 | Revised 30 November 2024 | Accepted 9 December 2024

DOI: 10.35755/jmedassocthai.2025.1.88-93-01699