Three Cases of Contact Allergy After Chemical Burns From Methylchloroisothiazolinone/Methylisothiazolinone: One With Concomitant Allergy to Methyldibromoglutaronitrile/Phenoxyethanol

BACKGROUND: Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) is known to be a contact sensitizer. It is used extensively in cosmetic products in low concentrations. Occupational exposure usually occurs with concentrated solutions and results in a different reaction pattern. RESULTS: Three workers developed chemical burns and subsequent sensitization after exposure to concentrated solutions of MCI/MI. One patient was also occupationally sensitized to methyldibromoglutaronitrile/phenoxyethanol. CONCLUSION: Exposure to concentrated solutions of some allergens can be severely irritating in the occupational setting and can probably induce sensitization.