Dermatomyositis

Diagnosis: Dermatomyositis

.024, 04/16/2001, 6:05 AM, 8C, 9281371 (306+288), 25%, Default Settin, 1/120 s, R24.0, G45.0, B81.0

Clinical Presentation

.024, 04/16/2001, 6:05 AM, 8C, 9281371 (306+288), 25%, Default Settin, 1/120 s, R24.0, G45.0, B81.0

Clinical History

Proximal muscle weakness with characteristic cutaneous findings. Malaise, dysphagia, arthralgia may be present. Screen for malignancy especially in adult-onset. Evaluate for ILD with anti-MDA5 antibodies.

Treatment

Skin: sun protection, topical corticosteroids, antimalarials (hydroxychloroquine). Muscle: systemic corticosteroids, steroid-sparing agents (methotrexate, azathioprine, mycophenolate, IVIG). Cancer screening. Pulmonary function tests for ILD.

Differential Diagnosis

• Systemic lupus erythematosus • Polymyositis • Contact dermatitis • Seborrheic dermatitis • Psoriasis • Drug eruption • Photosensitive eruption • Trichinosis

Key Learnings

• Classic cutaneous findings: heliotrope rash (violaceous periorbital erythema), Gottron papules (over MCPs/IPs/knees/elbows), V-sign, shawl sign • Gottron papules are pathognomonic for dermatomyositis • Adult dermatomyositis has significant malignancy association (~15-30%) — cancer screening essential • Myositis-specific antibodies: anti-Mi-2, anti-MDA5 (amyopathic DM with ILD risk), anti-TIF1-gamma (cancer association) • Amyopathic DM: skin disease without muscle involvement for ≥6 months • Anti-MDA5 DM associated with rapidly progressive interstitial lung disease • Nailfold capillaroscopy shows dilated, tortuous capillary loops with dropout

Tags: dermatomyositis, kodachrome