The key clinical features are itch, dryness and redness of skin. They are often accompanied by signs of damage secondary to scratching such as crusting, oozing and scabs. Crusted eczema is often sore due to excoriation and secondary bacterial infection. Blistering may suggest herpes simplex virus infection or impetigo. Atopic eczema usually starts on the cheeks and scalp in infants then adopts a limb flexural pattern in young children and adults. However, it may affect any part of the body and may occasionally be extensive enough to become erythrodermic. Relevant allergies should be suspected from the history and confirmed by skin prick testing or IgE-ImmunoCAP® testing on blood.