A 76-year-old woman with a recent diagnosis of dermatomyositis presented with a several-month history of asymptomatic linear erythematous plaques on her upper back area. She denied pruritus, trauma to the area, or scratching the lesions. She was being treated for dermatomyositis with prednisone (20 mg/d), hydroxychloroquine (200 mg twice a day), and topical corticosteroids, which had resulted in only partial improvement of her musculocutaneous symptoms.
The findings of the physical examination were notable for a periorbital violaceous eruption, Gottron papules on the knuckles, poikilodermatous changes of the upper chest area and proximal aspect of the extremities, and a psoriasiform eruption of the scalp. Also, linear, edematous, erythematous, nonscaling plaques were noted in a centripetal distribution in the upper back area (Figure 1). Periungual erythema with telangiectasias was present. The patient was negative for dermatographism. Mild proximal muscle weakness was noted bilaterally. A biopsy specimen from a linear upper back lesion was submitted for light microscopic (Figure 2) and direct immunofluorescence (Figure 3) studies.
Kimyai-Asadi A, Tausk FA, Nousari HC. A Patient With Dermatomyositis and Linear Streaks on the Back. Arch Dermatol. 2000;136(5):665-670. doi: