D1.37 - Which Came First? Atopic Dermatitis or occupational Allergic Contact Dermatitis in a Surgeon with Tropomyosin-Driven IgE Cross-Reactivity

Healthcare workers with atopic dermatitis (AD) are at increased risk of occupational hand eczema due to impaired skin barrier function and repeated exposure to rubber gloves. Rubber accelerators, particularly thiurams, and latex are among the most frequent causes of allergic occupational contact dermatitis (ACD). Concomitant IgE sensitization detected by multiplex assays may complicate diagnostic interpretation in atopic individuals.

A 33-year-old male surgeon presented with chronic hand eczema of three years’ duration, clearly exacerbated by surgical glove use and improving during work interruption. He also reported recurrent pruritus of the face, neck, and hands since childhood. Symptoms were reported to intensify following seafood consumption. Epicutaneous patch testing was performed using standardized baseline and rubber series allergens, along with samples of routinely used surgical gloves. ALEX² multiplex IgE testing was used to assess IgE-mediated sensitization, including house dust mite (HDM) components, seafood extracts, pan-allergens, and latex molecular allergens. Written informed consent was obtained.

Patch testing (PT) revealed a positive delayed-type hypersensitivity reaction to thiuram mix and latex-containing materials. Several gloves labeled as “latex-free” and “thiuram-free” elicited positive patch test reactions. A single glove model with an internal barrier layer tested negative and was identified as a safe alternative. To exclude IgE-mediated latex allergy, ALEX² multiplex IgE testing was performed, revealing elevated total IgE levels (122 kU/L), a selective HDM sensitization profile dominated by Der p 10 (tropomyosin) and Der p 11, and IgE positivity to all tested seafood extracts, a pattern consistent with cross-reactivity rather than primary food allergy. All latex molecular components were negative, effectively excluding IgE-mediated latex allergy. Targeted glove avoidance resulted in marked clinical improvement.

Clinical history and selective HDM sensitization indicate pre-existing AD that predisposed to subsequent occupational thiuram- and latex-induced ACD. Tropomyosin IgE cross-reactivity explained broad seafood extract positivity without primary food allergy. Combined PT and ALEX² molecular profiling is critical to differentiate overlapping type IV and type I sensitization, prevent misdiagnosis, and guide occupational management. Recognition of the atopic diathesis supports long-term control, as biologics approved for AD may represent future options in refractory contact dermatitis, preserving quality of life and work ability in healthcare professionals.