What should you know about cobalt and nickel allergy?

The immune system can become sensitised to cobalt, nickel or both. A rash may appear hours or days after contact and can include itching, redness, swelling, small blisters, dryness or cracking. Common contact points include jewellery, watch backs, belt buckles, clothing fasteners, tools, phones and some cosmetic or occupational items. The rash may extend beyond the exact contact area if the skin is inflamed. A history of repeated exposure helps, but appearance alone cannot confirm which metal is responsible.

Stop using the suspected item until it can be assessed, and keep a note of when each product touches the rash. Choose verified metal-safe alternatives, add a barrier between hardware and skin where appropriate, and avoid scratching. Wash gently and use a plain moisturiser to support the skin barrier. A clinician may recommend patch testing to identify the relevant allergen. For an active flare, treatment such as a topical corticosteroid may be prescribed for a limited course and body site; use it exactly as directed.

Arrange medical review if the rash keeps returning, spreads, becomes painful, cracks deeply or develops crusting or drainage. Seek urgent help for swelling of the lips or tongue, trouble breathing, faintness or widespread rapidly developing symptoms. These features need emergency assessment and should not be managed with avoidance alone.

Ask whether patch testing is suitable, which products may contain cobalt or nickel, how to protect the skin at work, how long prescribed cream should be used, and what to do if the rash returns after an apparently safe exposure.