Rubber Contact Dermatitis

Rubber contact dermatitis is allergic contact dermatitis from chemicals added to rubber during manufacture, mainly vulcanisation accelerators and antioxidants. It is a type IV reaction and differs from latex protein allergy, which is an immediate type I reaction.

Allergens. Thiurams, dithiocarbamates, mercaptobenzothiazole and mercapto mix, thioureas, diphenylguanidine, and the antioxidant N-isopropyl-N-phenyl-p-phenylenediamine in black rubber.

Sources. Surgical and household gloves, rubber boots, tyres, hoses, elastic bands, wetsuits, shoes and masks. Thiurams are also in some pesticides and fungicides.

Occupational groups. Healthcare, laboratory, food, cleaning, mechanics, rubber and tyre workers and farmers.

Epidemiology. Thiurams and carbamates are among the commonest causes of glove allergy. Delayed reactions appear 12 to 72 hours after contact.

Pathophysiology.

Small molecular chemicals leach from rubber into sweat and penetrate damaged skin. They bind proteins as haptens, causing a type IV hypersensitivity reaction.

Cross-reactions occur within chemical families. Thiuram sensitised patients can react to disulfiram.

• Itchy eczema at the contact area, often on the dorsal hands and wrists, spreading after repeated exposure.
• Patches matching glove or boot edges, elastic or straps.
• Chronic hand eczema with fissuring.
• Persistent disease despite apparent latex avoidance.

• Detailed product and glove history, including glove brand and material.
• Patch testing with a rubber additive series (thiuram mix, carba mix, mercaptobenzothiazole, mercapto mix, black rubber mix, thiourea); read at day 2 and day 4 or later.
• Patch testing of the patient's own gloves or items when needed.
• Latex specific IgE or prick test to exclude type I allergy.

Differential diagnosis. Latex contact urticaria, irritant contact dermatitis, allergic reaction to other glove components, atopic eczema, psoriasis, tinea.

• Avoid the specific allergen: use accelerator free gloves or gloves made from a different chemistry, with a thin inner glove of polyethylene or laminate for heavy work.
• Avoid disulfiram in thiuram allergic patients and avoid thiuram pesticides.
• Emollient applied liberally at least twice daily and after each handwash, long term.
• Clobetasol propionate 0.05% ointment topically to affected skin once or twice daily for up to 2 weeks, maximum 50 g weekly. Monitor skin atrophy, striae, telangiectasia and infection. Avoid on the face, flexures and genitals and on infected skin; use the lowest potency that works in pregnancy and avoid in children.
• Severe acute flare: prednisolone 40 mg orally once daily in the morning for 5 days, then 20 mg for 5 days, then 10 mg for 5 days, then stop. Maximum 40 mg daily. Monitor glucose, blood pressure and mood. Caution in diabetes, peptic ulcer and infection; acceptable in pregnancy when needed; no renal adjustment.
• Chronic disease: specialist review for phototherapy or systemic therapy.

Monitoring. Review at 4 to 6 weeks, then every 3 months; check the new gloves and products for recurrence.

Referral and escalation. Dermatology for patch testing; occupational physician for glove and process change; notification and compensation where required.

Special groups. Pregnancy: avoid potent steroids over large areas.