D2.73 - Secondary Domestic Exposure to Colophony as a Cause of Allergic Contact Dermatitis: A Case Report

Background

Allergic contact dermatitis (ACD) due to sensitization to colophony (colophonium), derived from rosin flux used in soldering processes, is a well-recognized occupational condition, particularly among metalworkers and welders exposed to resin fumes. Patch test registries and cohort studies report a prevalence of colophony sensitization ranging from 4% to 11% among workers evaluated for suspected occupational dermatitis. While direct occupational exposure is the main recognized risk factor, cases resulting from secondary domestic exposure are rarely reported.

Methods

We report a case of allergic contact dermatitis caused by indirect household exposure to colophony. Clinical evaluation included detailed history and epicutaneous patch testing with readings at 48 and 96 hours using the standard series (TRUE Test® with GEIDAC extension), cosmetic series, and the patient’s own cosmetic product.

Results

A 63-year-old woman with no relevant medical history was referred for evaluation of bilateral eyelid eczema. Symptoms developed after initiating a cosmetic cream containing vitamins B and C and resolved within 15 days after discontinuation and treatment with topical corticosteroids. Patch testing was negative for the cosmetic series and the implicated cream, but showed positive results to colophony at both 48 and 96 hours (Image 1). Further history revealed that her husband worked as a welder using rosin-based soldering resins and routinely returned home wearing contaminated work clothes, which the patient handled during laundering. The findings supported a diagnosis of allergic contact dermatitis due to sensitization to colophony from indirect domestic exposure.

Conclusion

This case highlights an uncommon but clinically relevant presentation of colophony-induced allergic contact dermatitis resulting from secondary household exposure via contaminated work clothing. It underscores the importance of thorough exposure history, including domestic contacts of occupationally exposed workers, and has implications for prevention strategies extending beyond the workplace.