D2.33 - Complex occupational allergic contact dermatitis: polysensitization in a worker exposed to metals, adhesives, and plastics

Background:Occupational allergic contact dermatitis (ACD) may result from exposure to multiple workplace allergens, leading to polysensitization. Establishing occupational causality requires careful clinical, occupational, and allergology assessment. The aim of this study was to report a case of occupational ACD with multiple sensitizations and to highlight the role of combined exposure to metals, adhesives, and plastic-processing agents.

Case report: A 48-year-old male worker, employed since 2009 in a manufactory of office furniture and professional equipment and supplies. His tasks involved immersion of metal parts in adhesives, assembly and heating processes of plastic components, plastic demolding using industrial oils, and manual finishing without personal protective equipment. He presented with pruritic erythematous and vesicular lesions evolving to desquamation on the dorsolateral aspect of the right hand. Symptoms occurred during workdays and markedly improved during periods of leave. Clinical examination showed fissured, scaly lesions on the dorsal and interdigital areas of the right hand and fingers, associated with hand xerosis. Mycological examination was negative. Patch testing to European baseline series revealed sensitization to cobalt, potassium dichromate, paraphenylenediamine, fragrance     mix I and hydroxyisohexyl-3-cyclohexene carboxaldehyde. Patch testing to plastic and glues series showed a sensitization to 2-n-octyl-4-isothiazolin-3-one. The ACD was likely of occupational origin, as evidenced by the clear work-related pattern of symptoms, exposure to metal components potentially containing chromium and cobalt to which the patient was sensitized, and possible contact with fragrance agents in demolding oils and adhesives ; including compounds from fragrance mix I and biocidal agents such as 2-n-octyl-4-isothiazolin-3-one, all corresponding to positive patch test reactions. This ACD was considered as a compensable occupational disease. The patient underwent a job reassignment to eliminate exposure to the sensitizing agents identified on patch testing.

Conclusion:This case illustrates the complexity of occupational ACD in polysensitized workers exposed to multiple allergens. Recognition of relevant occupational exposures, thorough patch testing, and targeted preventive measures including job reassignment and appropriate protective equipment are essential to preserve fitness for work and prevent disease progression.