A 25-year-old healthcare worker develops vesicles and erythema on the dorsum of both hands after wearing latex gloves. Patch testing at 48 and 96 hours shows a +++ reaction to thiuram mix but is negative for latex proteins. The type of hypersensitivity and the relevant component responsible are:
- A Type I IgE-mediated allergy to latex proteins (Hev b5, Hev b6)
- B Type III immune complex deposition to latex antigens
- C Type IV delayed hypersensitivity to rubber accelerant chemicals (thiurams) ✓
- D Irritant contact dermatitis from occlusion under gloves
Explanation
Allergic contact dermatitis (ACD) is a Type IV (delayed/cell-mediated) hypersensitivity reaction requiring sensitization followed by elicitation. Patch testing with the European standard series identifies the causative allergen; a positive reaction at 48-96 hours to thiuram mix indicates allergy to rubber accelerant chemicals (thiurams, carbamates, mercaptobenzothiazole) used in latex glove manufacturing — not to latex proteins themselves. This is an important distinction: latex protein allergy (IgE-mediated, Type I) causes urticaria, rhinitis, and anaphylaxis, not eczematous patches tested on patch test. For latex-accelerant ACD, treatment includes accelerant-free gloves (vinyl, nitrile without thiurams).
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
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Written and medically reviewed by the StethoPrep medical team.