Other dermatomyositis

M33.10 classifies adult dermatomyositis — a systemic inflammatory disease affecting skin and skeletal muscle — when the provider has confirmed the diagnosis but has not documented involvement of any specific organ system beyond the index disease.

M33.11 identifies adult-onset or non-juvenile dermatomyositis (classified as 'other' dermatomyositis within category M33.1) that is explicitly complicated by respiratory system involvement, such as interstitial lung disease or inflammatory pulmonary manifestations.

Dermatomyositis (adult-onset, non-juvenile) confirmed with objective myopathy — proximal muscle weakness, elevated creatine kinase, and/or EMG or biopsy findings consistent with inflammatory muscle disease.

M33.13 identifies adult-onset dermatomyositis — a systemic inflammatory disorder classified under 'Other dermatomyositis' — in which the characteristic cutaneous manifestations (heliotrope rash, Gottron's papules, mechanic's hands) are present but documented muscle inflammation or clinical myopathy is absent at the time of coding.

Other dermatomyositis (non-juvenile, adult-onset) with documented involvement of an organ system other than the respiratory tract or musculature — such as cardiac, gastrointestinal, or cutaneous visceral complications.