Idiopathic inflammatory myopathies: one year in review 2021.

Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of rare and complex connective tissue diseases, mainly characterised by inflammatory involvement of skeletal muscles. Several other organs may be affected, particularly lungs, heart, skin, gastrointestinal tract and joints, often determining the morbidity and mortality associated with these autoimmune disorders. The course is generally chronic and the onset subacute. This latter aspect, together with the rarity of these conditions, can result in a clinical challenge for the physician with a considerable diagnostic delay. The scientific literature makes continuous advances in the understanding of these diseases, in particular with regards to the pathogenesis, serological findings, diagnostic strategies and therapeutic approaches. The aim of this review is to highlight the most relevant literature contributions published on this topic over the last year.