Dermatomyositis

Dermatomyositis

Overview

Dermatomyositis is an idiopathic inflammatory myopathy (muscle disease) with characteristic cutaneous findings. The classic skin findings include a heliotrope (lilac-colored) rash on the eyelids, Gottron's papules over the knuckles, and photodistributed erythema. Muscle weakness affects the proximal muscles (shoulders, hips, thighs). In adults, dermatomyositis is associated with an increased risk of internal malignancy, necessitating age-appropriate cancer screening.

Key Symptoms

• Heliotrope rash — violaceous (lilac/purple) discoloration and edema of the eyelids
• Gottron's papules — pink or violaceous papules over the knuckles, elbows, and knees
• Shawl sign — erythema on the upper back, shoulders, and V of the neck
• Symmetric proximal muscle weakness (difficulty rising from a chair, climbing stairs, lifting arms)
• Mechanic's hands — rough, cracked, fissured skin on the lateral fingers
• Nail fold changes: dilated capillary loops and ragged cuticles

Affected Areas

Eyelids (heliotrope), Knuckles (Gottron's papules), Upper back and shoulders (shawl sign), V of the neck and chest, Proximal muscles, Nail folds

Care Instructions

1. See a dermatologist and rheumatologist for comprehensive evaluation and management.
2. Systemic corticosteroids and steroid-sparing immunosuppressants are first-line treatments for muscle disease.
3. Sun protection is critical as the rash is photosensitive.
4. Age-appropriate malignancy screening is essential at diagnosis and during follow-up, especially in adults.
5. Physical therapy to maintain muscle strength and prevent atrophy.
6. Topical corticosteroids, calcineurin inhibitors, or antimalarials (hydroxychloroquine) for skin disease.

Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice. Always consult a qualified dermatologist for diagnosis and treatment.

Prevalence: Rare; estimated incidence of 1-10 per million per year