Acute hip synovitis in children, also known as acute transient synovitis of the hip, temporary synovitis, toxic synovitis and allergic hip, is a common acute hip disorder in childhood, mostly with unilateral hip onset.
It is thought that infection, trauma or overexertion may be associated with the development of this disease. Children usually have a history of upper respiratory tract infection 1 to 4 weeks prior to the onset of the disease.