Medical Encyclopaedia › Contact dermatitis (short definition)
In brief: Contact dermatitis (contact eczema) is an inflammatory skin reaction triggered by direct contact with a substance. Typical features are redness, itching, blisters, scaling and, if it persists, thickened, cracked skin. A distinction is made between irritant (toxic) contact dermatitis caused by skin-damaging substances and allergic contact dermatitis caused by an acquired allergy. Both can be treated well if the trigger is identified and avoided.
Irritant contact dermatitis
Here the skin barrier is damaged directly, without an allergy being involved. Common causes are frequent hand washing, wet work, wearing gloves for long periods, cleaning agents and solvents, oils or friction. The hands are mainly affected. Occupations in nursing, medicine, hairdressing, catering, cleaning, construction and metalworking are particularly at risk. People with atopic eczema have more sensitive skin and develop it more easily.
Allergic contact dermatitis
In allergic contact dermatitis, the immune system has learned to react to a particular substance (delayed-type allergy, type IV). The reaction usually occurs one to three days after contact and can spread beyond the contact site. Common triggers are nickel in jewellery, belt buckles and buttons, fragrances, preservatives in cosmetics and cleaning products, dyes in hair colourants, chromate in cement and leather, rubber ingredients and some active substances in ointments. Once acquired, a contact allergy usually persists for life. In the EU, the REACH chemicals regulation limits nickel release from items in prolonged contact with the skin.
Diagnosis
A detailed history of occupation, hobbies, cosmetics, jewellery and medicines and the distribution of the skin changes are important. If an allergy is suspected, a patch test is carried out: test substances are applied to the back with patches, removed after about two days, and the skin is read on several days. Other skin diseases such as atopic eczema, psoriasis or fungal infections are ruled out.
Treatment
- Avoid the trigger: the most important step; in allergies, an allergy passport helps when checking product ingredient lists.
- Anti-inflammatory creams: during an acute flare, short-term corticosteroid preparations of appropriate strength; on the face and sensitive areas also calcineurin inhibitors.
- Skincare: emollient care, preferably fragrance-free, to restore the skin barrier.
- For severe, persistent hand eczema, specialist therapies such as phototherapy or systemic medicines.
Skin protection and work
In the workplace, skin protection, suitable protective gloves with cotton under-gloves for prolonged wear, gentle cleansing and care are part of the preventive concept. Occupational contact dermatitis can be recognised in Germany as an occupational disease (BK 5101, severe or repeatedly relapsing skin diseases). Even on suspicion, the dermatologist can send a dermatologist’s report to the statutory accident insurance, which then often covers treatment, skin protection training and other services in order to preserve the job. Normal treatment of contact dermatitis is paid for by the health insurers.
Related terms in the encyclopaedia
Eczema, Allergy, Type IV allergy, Patch test, Tacrolimus, Fragrances, Skin protection, Atopic eczema, Corticosteroids
Sources
- AWMF-S3-Leitlinie Diagnostik, Prävention und Therapie des Handekzems (Deutsche Dermatologische Gesellschaft)
- AWMF-S3-Leitlinie Durchführung des Epikutantests mit Kontaktallergenen und Arzneimitteln (Deutsche Dermatologische Gesellschaft)
- Verordnung (EG) Nr. 1907/2006 (REACH), Anhang XVII, Eintrag 27: Nickel
- Berufskrankheiten-Verordnung (BKV), Anlage 1, Nr. 5101: Schwere oder wiederholt rückfällige Hauterkrankungen
Note: This article is for general information and does not replace advice, diagnosis or treatment from a doctor, dentist or pharmacist. Last updated: October 2026.