Atopic dermatis (AD) is a very common inflammatory skin disease in childhood. Various doctors such as paediatricians, general practitioners, allergologists and dermatologists are regularly consulted by these children and their parents, but there is no clear consensus on the diagnostic work-up that should be performed when evaluating a child with eczema. A careful history, clinical examination and adequate documentation of disease severity are essential in all children with eczema, irrespective of their disease severity. AD is a clinical diagnosis; diagnostic criteria, such as the UK diagnostic criteria, can be helpful for an accurate definition of the disease. A careful history, including alarm symptoms, respiratory symptoms and the impact of the disease on psychosocial functioning is important. Clinical scoring lists such as SCORAD and EASI are well validated for clinical studies; they are, however, not very suitable tools in clinical practice. More simple scoring systems, such as Three Item Severity Score (TIS) and Investigator Global Assessment (IGA), are more easy to use for clinical record keeping in daily practice. Allergen testing in children with AD without a history of acute non-eczematous reactions after allergen exposure is not necessary. In very young children with eczema, not yet exposed to foods, routine allergen testing is not necessary. If in individual cases, the decision is made to perform allergen tests, oral challenges should performed to confirm the diagnoses of food allergy.