Background

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy of childhood. Untreated, this incurable disease, which has an X‐linked recessive inheritance, is characterised by muscle wasting and loss of walking ability, leading to complete wheelchair dependence by 13 years of age. Prolongation of walking is a major aim of treatment. Evidence from randomised controlled trials (RCTs) indicates that corticosteroids significantly improve muscle strength and function in boys with DMD in the short term (six months), and strength at two years (two‐year data on function are very limited). Corticosteroids, now part of care recommendations for DMD, are largely in routine use, although questions remain over their ability to prolong walking, when to start treatment, longer‐term balance of benefits versus harms, and choice of corticosteroid or regimen.