There are two distinct manifestations of this disease.
The first is seen in a man who eats undercooked beef or pork. After one or two days, he develops nausea, vomiting, abdominal pain, bloating, and watery diarrhea. Symptoms are self-limiting and resolve within 36 hours.
The second is a patient who traveled to rural Malaysia and encountered snakes. After about a week and a half to two weeks, he develops fevers to 39 C, rigors, myalgias, and headaches. This becomes a relapsing-remitting course with episodes lasting 4-5 days. You note myositis with muscle tenderness and muscle swelling, especially in the muscles of mastication, calf muscles, and superficial back muscles. Here's a T2-weighted short tau inversion recovery (STIR) MRI sequence:
In both cases, patients have eosinophilia and lymphocytosis. The other cell lines are fine. AST, ALT, and GGT are elevated moderately (less than twice the upper limit of normal) and CK is moderately elevated. A biopsy is shown below:
Challenge: What's the diagnosis?
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