Cross‐reactivity between methylisothiazolinone, octylisothiazolinone and benzisothiazolinone using a modified local lymph node assay

BACKGROUND: In the light of the exceptionally high rates of contact allergy to the preservative methylisothiazolinone (MI), information about cross-reactivity between MI, octylisothiazolinone (OIT) and benzisothiazolinone (BIT) is needed. OBJECTIVES: To study cross-reactivity between MI and OIT, and between MI and BIT. METHODS: B cells in the auricular draining lymph nodes. RESULTS: T cells was observed between mice challenged with MI compared with mice challenged with BIT and OIT. CONCLUSIONS: The data indicate cross-reactivity between MI, OIT and BIT, when the potency of the chemical was taken into account in choice of challenge concentration. This means that MI-sensitized individuals may react to OIT and BIT if exposed to sufficient concentrations.