Dermatomyositis - Signs and Symptoms

Signs and Symptoms

The main symptoms include skin rash and symmetric proximal muscle weakness which may be accompanied by pain. The pain may resemble the type experienced after strenuous exercise. Some dermatomyositis patients have little pain, while in others (esp. in JDM), the pain may be severe. It is important to remember that this condition varies from person to person in many ways. Also in many cases muscle may deteriorate and render the patient temporarily paralyzed unable to walk, run, get out of bed, or even swallow food and liquids.

Skin findings occur in dermatomyositis but not PM and are generally present at diagnosis. Gottron's sign is an erythematous, scaly eruption occurring in symmetric fashion over the MCP and interphalangeal joints (can mimic psoriasis). The heliotrope or "lilac" rash is a violaceous eruption on the upper eyelids and in rare cases on the lower eyelids as well, often with itching and swelling (most specific, though uncommon). Shawl (or V-) sign is a diffuse, flat, erythematous lesion over the back and shoulders or in a "V" over the posterior neck and back or neck and upper chest, which worsens with UV light. Erythroderma is not a flat, erythematous lesion similar to the shawl sign but located in other areas, such as the malar region and the forehead. Periungual telangiectasias and erythema occur.

Mechanic's hands (also in PM) refers to rough, cracked skin at the tips and lateral aspects of the fingers forming irregular dirty-appearing lines that resemble those seen in a laborer (this is also associated with the anti-synthetase syndrome). See: sclerodactyly. Psoriaform changes in the scalp can occur. Centripetal flagellate erythema comprises linear, violaceous streaks on the trunk (possibly caused by itching pruritic skin). Calcinosis cutis (deposition of calcium in the skin) is usually seen in juvenile dermatomyositis, not adult dermatomyositis. Dysphagia (difficulty swallowing) is another feature, occurring in as many as 33% of cases.