Diagnosis: Dermatomyositis
Description: Elbow rash
Morphology: Photosensitive distribution
Site: Elbow
Sex: M
Age: 67
Type: Clinical
Submitted By: Ian McColl
Differential DiagnosisHistory:
Dermatomyositis is an autoimmune disease with many characteristic skin signs often in a photoexposed distribution. There is often periocular oedema and a curious violaceous discoloration of the periocular skin. The cuticles are described as ragged. The distribution of erythema on the back of the hands is centred over the joints with sparing of the intervening skin. The latter is more commonly a feature of lupus erythematosus. Erythema over the upper chest and back is known as the shawl sign.
Dermatomyositis can be a marker of internal malignancy