Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thickens over time. While the condition may occur at any age, it typically starts in childhood, with changing severity over the years. In children under one year of age, much of the body may be affected. As children get older, the areas on the insides of the knees and elbows are most commonly affected. In adults, the hands and feet are most commonly affected. Scratching the affected areas worsens the symptoms, and those affected have an increased risk of skin infections. Many people with atopic dermatitis develop hay fever or asthma.The cause is unknown but believed to involve genetics, immune system dysfunction, environmental exposures, and difficulties with the permeability of the skin. If one identical twin is affected, the other has an 85% chance of having the condition. Those who live in cities and dry climates are more commonly affected. Exposure to certain chemicals or frequent hand washing makes symptoms worse. While emotional stress may make the symptoms worse, it is not a cause. The disorder is not contagious. A diagnosis is typically based on the signs and symptoms.
If topical corticosteroids and moisturisers fail, short-term treatment with topical calcineurin inhibitors such as tacrolimus or pimecrolimus may be tried, although their use is controversial, as some studies indicate that they increase the risk of developing skin cancer or lymphoma. A 2007 meta-analysis showed that topical pimecrolimus is not as effective as corticosteroids and tacrolimus. A 2015 meta-analysis, though, indicated that topical tacrolimus and pimecrolimus are more effective than low-dose topical corticosteroids, and found no evidence for increased risk of malignancy or skin atrophy. In 2016, crisaborole, an inhibitor of PDE-4, was approved as a topical treatment for mild-to-moderate eczema.Other medications used for AD include systemic immunosuppressants such as ciclosporin, methotrexate, interferon gamma-1b, mycophenolate mofetil, and azathioprine. Antidepressants and naltrexone may be used to control pruritus (itchiness). Leukotriene inhibitors such as monteleukast are of unclear benefit as of 2018.In 2017, the monoclonal antibody(mAb) dupilumab under the trade name Dupixent was approved to treat moderate-to-severe eczema. In 2021, an additional monoclonal antibody, tralokinumab, was approved in the EU & UK with the trade name Adtralza then later in the US as Adbry for similarly severe cases.