Abstract
Polyarteritis in infancy is very rare, difficult to diagnose and invariably fatal. A 6‐month‐old girl who presented with a prolonged unexplained fever and was subsequently demonstrated at post‐mortem examination to have polyarteritis is described. The combination of polyarteritis with some unusual presenting features suggests that the case described is one of the Mucocutaneous Lymph Node Syndrome (M.L.N.S.) or Kawasaki Disease. Polyarteritis and Kawasaki Disease are discussed with reference to the case described.