Nickel is the single most common patch-test positive worldwide — including among AllerNote users, where it sits near the top of our community data. Most people associate it with jewellery and belt buckles, but cosmetics deserve a place on the checklist too.

Where nickel hides in cosmetics

You won't find "nickel" on an ingredient list — it's never added deliberately. It arrives as a trace contaminant:

  • Pigmented products. Iron oxides, ultramarines, and other mineral pigments can carry nickel traces from their source ores. Eye shadow, eyeliner, mascara, and mineral foundations are the usual suspects.
  • Dark shades more than light ones. More pigment load generally means more trace metal.
  • Tools and packaging. Metal eyelash curlers, mascara wands' metal cores, tweezers, and metal-clad compacts contact skin directly — classic sources of eyelid and fingertip dermatitis.
  • Green-tinted glass and some brushes occasionally test positive too.

The eyelid clue

Eyelid skin is the thinnest on the body, and eyelid dermatitis is the textbook presentation of cosmetic nickel exposure — often from eye makeup, curlers, or nickel transferred from fingers. If your eyelids flare but your face tolerates products fine, think nickel (and its frequent companion, cobalt).

What you can actually do

  1. Favour low-pigment, cream-based formulas over powder minerals if you're strongly reactive.
  2. Swap metal tools for plastic or coated versions — the eyelash curler is the classic fix.
  3. Look for "nickel-tested" claims. Some European brands certify nickel below 1 ppm ("nickel tested" / "0.00001%") — one of the few front-of-pack claims that's actually useful.
  4. Watch cross-reactors and companions. Cobalt allergy commonly travels with nickel; your patch-test sheet will say.
  5. Mind the non-cosmetic load too — nickel exposure is cumulative across jewellery, keys, phones, and even diet in severe cases; your dermatologist can advise whether a low-nickel diet is relevant for you.

Because nickel is a contaminant rather than a listed ingredient, label scanning can't directly detect it — this is one allergy where product type and tools matter more than the INCI list. For the rest of your allergen profile, the usual rule applies: check every label against your patch-test results.