Octylisothiazolinone, an additional cause of allergic contact dermatitis caused by leather: case series and potential implications for the study of cross-reactivity with methylisothiazolinone

Abstract

Non-occupational sensitization to OIT from leather may occur. Patch test concentrations of >250 ppm pet. may be necessary for diagnosis, and to show cross-reactivity with MI. Safer use limits for OIT in the leather industry may be needed.

Severe allergic contact dermatitis caused by octylisothiazolinone in a leather sofa: two new cases

“…Mainly occupational dermatitis has been attributed to OIT. However, recently, several non‐occupational cases, resulting from its use in leather goods, including one sofa, have been reported . A similar case of sofa dermatitis, caused by MI in a leather care product, has been described .…”

“…OIT is an isothiazolinone derivative that is not as frequently used as a biocide and reported as a contact allergen as MI and MCI/MI . It may be present in water‐based paints, glues, cutting and cooling fluids, wood preservatives, household detergents, textiles, leatherwear, and fur . Although it is not authorized for use in cosmetics, illicit use in such products has been reported .…”

“…A similar case of sofa dermatitis, caused by MI in a leather care product, has been described . In chemical products, no safe use concentrations of OIT have been determined, and no concentration limits have been imposed on the (leather) industry so far, although rules of ‘self‐regulation’ seem to exist .…”

“…Partial immunological cross‐reactions between non‐chlorinated isothiazolinone derivatives, and between MI and OIT in particular, have been suggested to occur , but are detected only if these derivatives are patch‐tested in high enough concentrations . In daily clinical practice, primary sensitization is often attributable to MI, through the use of cosmetics, with sometimes non‐relevant cross‐reactivity to OIT .…”

“…Recently, 6 cases of non‐occupational allergic contact dermatitis caused by octylisothiazolinone (OIT; CAS no. 26530‐20‐1) present in leather goods, including one sofa, were reported . Here, we describe 2 new cases of severe dermatitis caused by OIT in leather sofas.…”