INTRODUCTION
Dermatomyositis is an idiopathic autoimmune disease, characterized
by skin and skeletal muscle inflammation, which often presents in insidious fashion. Classic dermatologic findings include a violaceous heliotrope rash around the eyes, Gottron's papules on the knuckles, and ragged cuticles at the proximal nailfold. Herein, we present an atypical case of dermatomyositis with rapid progression and distinctive skin morphology.
CASE REPORT
A previously healthy 39 year-old man presented to our institution
with 3 weeks of fatigue, muscle weakness, and rash. At the onset of illness, he had experienced “cold-like” symptoms, including sore throat, fever, and night sweats, along with a pruritic
eruption on his malar cheeks. Over the following week, the rash spread to include his upper chest, upper back, and extensor
extremities. Short courses of azithromycin, penicillin, and prednisone did not improve his symptoms. His muscle weakness
and myalgias worsened, and at the time of presentation, he could not walk more than a few steps.
On physical examination, the patient was afebrile but ill-appearing.
His voice was hoarse and he was unable to sit up or roll to the side without assistance. Skin examination was remarkable for facial edema and bright violaceous patches involving
the full face, neck, upper chest, upper back, extensor elbows, and anterior thighs. The chest and back were marked with linear violaceous streaks (Figure 1). The patient was not dermatographic. He denied having scratched his back for the past several days due to his muscle weakness.
Laboratory studies were notable for a creatine kinase (CK) of 14,823 U/L (normal 55-380 U/L), which rose over the first five hospital days to over 30,000 U/L (Figure 2). Aldolase was elevated
at 80.4 U/L (normal < 8.1 U/L). Anti-nuclear antibodies were negative at a titer < 1:40. Epstein-Barr virus, cytomegalovirus,
and parvovirus B19 could not be detected in the serum by polymerase chain reaction. Hepatitis B and coxsackie virus serologies
were also negative. CT scans of the chest, abdomen, and pelvis did not show evidence of interstitial lung disease or occult malignancy.
A skin biopsy from the upper back revealed vacuolar change at the dermo-epidermal junction, a sparse perivascular lymphocytic
infiltrate, and a marked increase in dermal mucin, consistent with a diagnosis of dermatomyositis (Figure 3).
Treatment with pulse methylprednisolone was initiated on hospital day 4 after the diagnosis had been confirmed histopathologically.
The rash and muscle weakness began improving within three days of starting treatment. One week after starting treatment, the patient was fully ambulatory and was discharged from the hospital on a course of prednisone and mycophenolate mofetil.
DISCUSSION
The diagnosis of dermatomyositis can often be made clinically
by the observation of classic dermatologic changes in the setting of slowly progressive proximal muscle weakness.
1 Confirmation with skin and/or muscle biopsy is recommended, especially when the clinical presentation is atypical. Mortality from dermatomyositis is most commonly due to interstitial lung disease or underlying internal malignancy;
therefore, screening with high-resolution chest CT or pulmonary function tests and a thorough search for occult malignancy are important aspects of the initial workup.2,3 Treatment typically consists of high-dose corticosteroids followed by a slow steroid taper with or without an additional
immunosuppressive agent, including mycophenolate mofetil, methotrexate, azathioprine, or cyclophosphamide, or an antimalarial agent, such as hydroxychloroquine. In one series of 14 adults with dermatomyositis, the average duration of therapy to achieve remission was 42 months, with muscle symptoms responding an average of 23 months prior to cutaneous clearance.3
Fulminant dermatomyositis, defined as the rapid progression of debilitating or life-threatening disease with a CK of greater than 10,000 U/L, is very uncommon. A report of two previously
healthy young men who developed respiratory failure and ultimately died from fulminant dermatomyositis found evidence of endothelial cell infection with herpes simplex virus-
2 or parvovirus B19 in target tissues.4 While viral studies were negative in our patient (and in situ viral studies from
