Juvenile dermatomyositis

It is not uncommon for patients to present respiratory impairment secondary to weakness of the muscles involved in respiration, which usually recovers rapidly after initiation of immunosuppressive therapy. 

Pulmonary involvement in JDM is rare, being present in less than 5% of patients. Its presence is a poor prognostic factor, so despite its low frequency, given that it will condition immunosuppressive treatment, it is recommended that all patients with JDM undergo a baseline study by means of pulmonary function and diffusion tests. If these tests are altered, it is recommended to complete the imaging study with chest X-ray and/or high-resolution pulmonary CT.