Review Question - QID 210418

A 23-year-old man presents to the emergency department with severe pain in his arms, legs, chest, and back. He has experienced this before and was treated 2 months ago for a similar concern. He notes these episodes when exerting himself or when he is dehydrated. His temperature is 100°F (37.8°C), blood pressure is 127/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for tenderness to palpation of the patient's legs, chest, abdomen, and arms. Laboratory values are obtained and shown below.

Hemoglobin: 10 g/dL
Hematocrit: 30%
Leukocyte count: 8,500/mm^3 with normal differential
Platelet count: 199,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.9 mEq/L
HCO3-: 25 mEq/L
BUN: 23 mg/dL
LDH: 327 U/L
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Ca2+: 10.2 mg/dL
AST: 12 U/L
ALT: 10 U/L

Which of the following is the most likely diagnosis?