Occupational airborne allergic contact dermatitis from a PVA‐based coating formulation in a pharmaceutical worker—A challenging case report

Occupational allergic diseases caused by drugs are frequently reported in healthcare and pharmaceutical industry workers.1, 2 Although drug-induced allergic contact dermatitis usually presents as hand eczema, airborne dermatitis may also occur.1, 3 A non-atopic 51 year-old female patient, working in the pharmaceutical industry for 3 years, started suffering from rhino-conjunctivitis and itchy hands since 1 year, related to handling drugs during their manufacturing process. Subsequently, she developed clear erythema and eczematous lesions on the hands, neck and face, despite wearing personal protective equipment (Figure 1). Symptoms disappeared during weekends and on holidays, but re-occurred and worsened on working days. The severity of the dermatitis led to several courses of oral corticosteroid treatment. Patch tests (PT) were carried out with European baseline series and the suspected whole formulation (finished) drugs on the back, using a 2-day occlusion and IQ Ultra Chambers (Chemotechnique Diagnostics, Vellinge, Sweden). Other potential culprits, such as gloves, were also tested (semi-open). The results were negative on day (D) 2, D4 and D7. Skin prick tests with aeroallergens and latex, as well as specific IgE to latex, were equally negative. Subsequently, PT with the chemical active components and excipients of the drugs were performed (substances provided by the pharmaceutical laboratory; all diluted at 30% in petrolatum) (Table S1). The results on D2 and D4 now showed a positive PT reaction to Yellow Pigment and Opadry® II Brown (polyvinyl alcohol (PVA)-based formulation used for pharmaceutical tablet coating) (Figure 2). In order to rule out an irritant reaction, the same PT were carried out on three healthy volunteers, all workers from the same pharmaceutical laboratory, who were regularly exposed to similar substances, as well on three healthy volunteers not employed in the same factory. All results were negative on D2 and D7. Our patient is currently on medical leave and remains asymptomatic. No reports of airborne allergic contact dermatitis from PVA-based coating formulations (Opadry®) or yellow pigment in an occupational context were found in the literature. In our case, PT with excipients provided from the pharmaceutical laboratory was particularly important due to the lack of standardised commercial tests. The initial tests carried out with the entire finished formulation of the drugs were negative, probably because the concentration of excipients present in these was not high enough to trigger a PT reaction. Moreover, our case emphasizes the importance and relevance of identifying the exact culprit agent(s) in order to recommend and install appropriate avoidance measures. As excipients are rarely suspected, and usually considered hidden allergens, greater awareness concerning their sensitising potential may be needed.4 In conclusion, we report a first case of occupational airborne allergic contact dermatitis from a PVA-based coating formulation (Opadry®). The widespread utilisation of polymers in diverse applications highlights their potential as (occupational) contact sensitizers. Inês Farinha: Conceptualization; investigation; methodology; writing – original draft. Graça Loureiro: Conceptualization; investigation; methodology; writing – review and editing; supervision. Inês Nunes: Investigation; writing – review and editing. Ana Todo Bom: Writing – review and editing. Emília Faria: Conceptualization; writing – review and editing; supervision. The authors declare that there is no financial or commercial conflict of interest regarding the publication of this article. Table S1. List of substances tested (with negative result). All substances were tested using petrolatum as vehicle at a concentration of 30%. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.