A 39-year-old man presents to the emergency department with 3 days of progressive bilateral leg pain, nausea, and malaise. He denies having a fever, back pain, swelling, dyspnea, injury, overuse, or other complaints. He has no significant past medical history, but he does have prior visits related to methamphetamine abuse.
On physical exam, his vital signs are normal. He has multiple small scabs on his arms but none on his legs. None of the scabs appears to be infected. Head and neck exam is normal, as is examination of the heart, lungs, and abdomen. His legs appear normal, without redness or edema and with good pulses. Strength is intact.
Lab work shows a blood urea nitrogen (BUN) level of 40 mg/dL, a creatinine level of 4.4 mg/dL, alanine transaminase (ALT) of 124 U/L, and aspartate transaminase (AST) of 1008 U/L. The complete blood count (CBC), chemistry, and liver function tests (LFTs) are all normal.
What additional test should you order to make the correct diagnosis?
What is the treatment?
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