[Anti-MDA5 dermatomyositis. Literature review]

Dermatomyositis positive anti-melanoma differentiation-associated gene 5 (anti-MDA5 DM) is a rare disease that represents less than 2%. The prevalence of anti-MDA5 DM ranges from 7 to 60%, with higher prevalence in Asian (11-60%) and women. The clinical picture may be variable and is accompanied by the typical features of dermatomyositis, such as periorbital heliotrope (blue-purple) rash with edema, erythematous rash on the face, or the anterior chest (in a V-sign), and back and shoulders (in a shawl sign), violaceous papules or plaques located on the dorsal part of the metacarpophalangeal or interphalangeal joints, which are pathognomonic by definition; yet, one of the most striking signs is the painful ulceration skin that is found in 82% of cases, which is deep and in punching holes or showing hyperkeratotic crusts. For diagnosis is necessary the typical DM rashes (Gottron's papules or Gottron's sign and heliotrope rash), along with either an "interface dermatitis" skin pathology or evidence of myositis or a MSA (myositis-specific autoantibodies). Immunoprecipitation is the gold standard method to detect MSA. Combinations of glucocorticoids and immunosuppressants are used for treatment; besides, it is necessary the detection of rapidly progressive interstitial disease (RP-ILD) with a high-resolution CT because of its high association with fatal prognosis.