Contact dermatitis

Contact dermatitis is skin inflammation caused by contact with something that irritates the skin or triggers an allergic reaction. It can cause itching, dryness, cracking or blisters. Identifying the exposure matters because repeatedly treating the rash without changing the trigger may allow it to keep returning.

What is the difference between irritation and allergy?

Irritant contact dermatitis happens when an exposure damages the skin barrier. Allergic contact dermatitis involves the immune system reacting to a substance. They can look similar, and a product described as natural or gentle can still cause a reaction in some people.

Think about where the rash appears and what touches that area: gloves, cleaning products, cosmetics, jewellery, adhesives or workplace materials. Take photographs and keep the packaging of new products. If symptoms relate to work, describe the tasks and protective equipment rather than only naming your occupation.

For the Australian guidance behind this explanation, see Healthdirect Australia: Contact dermatitis - treatments, symptoms and prevention.

How is the cause worked out?

A clinician examines the pattern and asks about exposures and timing. Patch testing may be considered for suspected contact allergy; it is different from assuming every rash needs a general allergy blood test. Avoid deliberately re-exposing yourself to a product to prove it caused the reaction.

Gentle skin care and avoiding a suspected irritant may help while you seek advice. Ask before applying multiple new products, because that can make the picture harder to interpret. A doctor decides which treatment is appropriate for the site, severity and your other health needs.

When does a rash need prompt review?

Seek review if it is widespread, painful, worsening rapidly or affecting your daily activities. Fever, pus or feeling unwell may indicate infection. Facial or throat swelling and breathing difficulty require emergency help. Photographs can support telehealth, but blistering, severe pain or suspected infection may require an examination.

Where to go next

Read online doctor consultations to understand the relevant service. A doctor decides whether a consultation, examination, referral or another pathway is appropriate for your situation.