Contact dermatitis results from skin contact with an exogenous substance. It can be caused by direct contact, airborne particles, vapours or light. Individuals of any age can be affected. The two most common variants are irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). ICD is more common and has a worse prognosis. ICD is a form of eczema and is induced by direct inflammatory pathways without prior sensitisation. If eczema is recurrent/persistent, or occurs in an individual with no previous history of eczema, contact dermatitis should be considered. If ACD is suspected the patient should be referred to secondary care for patch testing.