Nickel Contact Dermatitis

Nickel contact dermatitis is allergic contact dermatitis from skin contact with nickel in metal items, tools and jewellery. It is the commonest contact allergy worldwide.

Epidemiology. Roughly 10 to 20% of women and 1 to 5% of men are sensitised in adult patch test series. Prevalence fell in regions that limit nickel release from products in prolonged skin contact.

Occupational exposure. Hairdressers, metalworkers, cleaners, caterers, cashiers handling coins, electroplaters, dental and healthcare staff handling instruments, and workers in wet work with metal contact.

Sources. Jewellery, watches, buttons, zips, belt buckles, tools, keys, coins, mobile phones, stainless steel utensils and orthopaedic or dental metal.

Course. Sensitisation is lifelong. Hand eczema from nickel is often chronic.

Pathophysiology.

Sweat and moisture release nickel ions, which pass through the skin and bind proteins to form haptens. Nickel can also activate innate immune receptors directly.

Antigen specific T cells produce a type IV hypersensitivity response on re-exposure.

• Itchy erythematous eczema at contact sites: earlobes, wrists, neck, periumbilical skin, finger webs and hands.
• Vesicles, fissuring and lichenification in chronic disease; spread to distant sites (id reaction).
• Hand eczema in wet work occupations, sometimes with pompholyx like change.
• Flares after ingestion of nickel rich foods in a small number of patients (systemic contact dermatitis).

• History of metal contact, piercing, occupation and distribution.
• Patch testing with nickel sulphate 5% in petrolatum; read at day 2 and day 4 or later. Irritant reactions can mimic weak positives.
• Dimethylglyoxime spot test: a pink colour indicates nickel release from items.
• Patch testing for co-sensitisation (cobalt, chromate) in hand eczema.
• Skin scrapings when tinea is a possibility.

Differential diagnosis. Irritant contact dermatitis, atopic eczema, allergic contact dermatitis to other metals, rubber or fragrance, psoriasis, tinea, pompholyx.

• Avoid nickel contact: nickel free jewellery and tools, coating of metal items with clear nail varnish as a temporary measure, and protective gloves with cotton liners.
• 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.
• Face and flexures: hydrocortisone 1% cream topically once or twice daily for up to 7 days; do not exceed 2 weeks on the face. Monitor for atrophy.
• 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 hand eczema that persists: alitretinoin, phototherapy or other specialist treatment as set out by dermatology.
• Systemic nickel allergy: a supervised low nickel diet for 4 to 8 weeks may help a minority; evidence is weak and the diet should not be prolonged.

Monitoring. Review at 4 to 6 weeks, then every 3 months until stable; re-check avoidance measures at work and at home.

Referral and escalation. Dermatology for patch testing and chronic hand eczema; occupational physician for workplace change; notification and compensation where required.

Special groups. Pregnancy: avoid systemic retinoids. Children: advise early nickel free piercings.