Contact Dermatitis: What Triggers It and How to Avoid Flare-Ups
Contact dermatitis is your skin reacting to something it touches. Here's the difference between irritant and allergic types, the usual triggers, and how to avoid them.
What it is
Contact dermatitis is inflammation of the skin caused by something it has touched. It comes in two forms. Irritant contact dermatitis is direct damage from a harsh substance (soaps, solvents, frequent handwashing) and can affect anyone. Allergic contact dermatitis is an immune reaction to a specific substance you have become sensitised to, and it recurs every time you meet that substance.
The usual triggers
A small number of culprits cause most allergic cases: fragrance, nickel, preservatives (especially methylisothiazolinone and formaldehyde-releasers), lanolin, and rubber chemicals. Irritant cases are often down to soaps, detergents and repeated wet work.
How to tell them apart
Irritation tends to sting soon after contact and settles when you stop. An allergy is itchier, often appears 12 to 72 hours later, and keeps coming back. The delay and the recurrence are the giveaways.
How to avoid flare-ups
- Switch to fragrance-free, short-ingredient products.
- Protect hands with gloves for wet or cleaning work, and moisturise often.
- Reintroduce products one at a time so you can spot a culprit.
- If you have a known allergen, learn its alternative names so it cannot slip past you.
When to see a doctor
If it is widespread, blistering, or not settling, see a GP or dermatologist. Persistent or unexplained cases are worth patch testing, which identifies the exact allergen.
Tools that help
To check a product, INCIBeauty lets you look up a product and read plain-language notes on each ingredient, with a community that rates them, and a free browser extension like Clearya flags ingredients of concern automatically as you shop online. These rate a product on general criteria rather than against your own list.
Once you know what you are screening for, a personal-list app like ClearaScan lets you save the ingredients you react to once and scan any product to flag only your triggers. It also keeps a Reaction Journal for flare-ups, a shared Care Circle so family or carers can scan for you, and a Trusted Products list for items you have cleared, and it is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)