A study of occupational contact dermatitis in the pharmaceutical industry

Occupational allergic contact dermatitis to Piperamido Nitrotoluene in pharmaceutical workers: a case series

BACKGROUND

Imatinib mesylate is a first generation tyrosine kinase inhibitor. Piperamido Nitrotoluene, also known as F5, is an intermediate used in the manufacturing of Imatinib. We present a case series of allergic contact dermatitis to F5 in pharmaceutical workers.

METHODS

Four male pharmaceutical workers were referred between 2007 and 2021 with new dermatitis predominantly affecting the periorbital region. All were involved in the production of Imatinib and particularly exposed to F5. Following medical history and examination, they underwent patch testing to standard series and F5 diluted in white soft paraffin (WSP) RESULTS: All patients tested positive confirming a diagnosis of contact allergy to F5. The first case tested positive to F5 diluted to 1% in WSP, the second to F5 diluted to 10% in WSP, the third and fourth to F5 diluted to 1% and 10% in WSP. In all four cases, dermatitis resolved when they were removed from exposure to F5.

CONCLUSIONS

To our knowledge, these are the first cases of allergic contact dermatitis to F5 confirmed by patch testing in the literature. In February 2016 a generic formulation of Imatinib entered the market. Globalised production of Imatinib may result in further cases presenting to dermatology departments worldwide.

In vitro methods for hazard assessment of industrial chemicals - opportunities and challenges

Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity immune reaction mediated by T-lymphocytes as a result of repeated exposure of an allergen primarily on skin. ACD accounts for up to 95% of occupational skin diseases, with epoxy resins implicated as one of the most common causes of ACD. Efficient high-throughput in vitro screening for accurate identification of compounds and materials that may pose hazardous risks in the workplace is crucial. At present, the murine local lymph node assay is the 'method of choice' for predicting the sensitizing potency of contact allergens. As the 3Rs principles of reduction, refinement, and replacement in animal testing has gained political and economic momentum, several in vitro screening methods have been developed for identifying potential contact allergens. To date, these latter methods have been utilized primarily to assess the skin sensitizing potential of the chemical components of cosmetic products with scant research attention as to the applicability of these methods to industrial chemicals, particularly epoxy resins. Herein we review the currently utilized in vitro methods and identify the knowledge gaps with regard to assessing the generalizability of in vitro screening methods for assessing the skin sensitizing potential of industrial chemicals.