(BMJ) - A 15-yo girl with bilateral periorbital reddish-purple rash and swelling x 3 months developed a V-neck rash, periungual vascular dilatation, fever, leukocytopenia, polyarthralgia and symmetrical proximal muscle weakness. What is the diagnosis?
Basilar skull fracture
Allergic contact dermatitis
Lambert–Eaton myasthenic syndrome
Juvenile dermatomyositis
Neuroblastoma
You are correct. Periorbital heliotrope dermatitis, V-neck rash, and proximal muscle weakness are useful diagnostic findings in this systemic autoimmune myopathy. Symptoms resolved after prednisone and cyclophosphamide treatment.