Dermatomyositis — Clinical Case (Wikimedia Commons)

Diagnosis: Dermatomyositis

Dermatomyositis, Gottron's papules. Erythematous plaques overlying the elbows in two patients with juvenile dermatomyositis. In some patients, small erythematous plaques may overly the extensor aspect. Clinical photograph sourced from Wikimedia Commons (CC BY-SA 3.0). Attribution: Elizabeth M. Dugan, Adam M. Huber, Frederick W. Miller, Lisa G. Rider.

Clinical Presentation

Heliotrope rash: violaceous erythema of upper eyelids with edema. Gottron papules: violaceous papules over MCPs, PIPs, elbows, knees. V-sign: erythema of anterior neck/chest. Shawl sign: posterior shoulders/upper back. Mechanic's hands: hyperkeratotic fissured fingertips.

Clinical History

Bimodal: childhood (5-15 years) and adult (40-60 years). Adults >40: screen for underlying malignancy (ovarian, breast, lung, GI — especially within 3 years of diagnosis). Proximal muscle weakness: difficulty climbing stairs, raising arms. Dysphagia may indicate esophageal involvement.

Treatment

Sun protection (photosensitive). Muscle disease: systemic corticosteroids + steroid-sparing agent (methotrexate, azathioprine, mycophenolate, IVIG). Skin: topical corticosteroids, antimalarials (hydroxychloroquine). Refractory: rituximab, IVIG. Malignancy screening essential.

Differential Diagnosis

Systemic lupus, Polymyositis, Contact dermatitis, Drug eruption, Psoriasis, Photosensitivity dermatitis

Key Learnings

Gottron papules are pathognomonic for dermatomyositis. Age-appropriate cancer screening is MANDATORY — CT chest/abdomen/pelvis, colonoscopy, mammography, pelvic exam. Myositis-specific antibodies guide prognosis: anti-Mi-2 (good), anti-MDA5 (ILD risk), anti-TIF1-γ (malignancy risk).

Tags: dermatomyositis, autoimmune, myopathy, connective tissue, paraneoplastic