A 28-year-old man with no significant reported medical history presented to the emergency department with a bilateral palmar rash and neck stiffness during a several-day flu-like illness. He noticed urinary frequency without dysuria or penile discharge approximately two days before the headache began. He then developed a throbbing headache, chills, marked neck stiffness, and intermittent vertigo. The neck stiffness improved before evaluation. He also developed a dry cough that worsened when he leaned back or lay down. The timing of the cough relative to the rash was unclear. Diffuse arthralgias, greatest in the right knee, and generalized myalgias began the day before presentation. He reported mild nausea without vomiting and maintained light oral intake. He denied fever, chest pain, dyspnea, abdominal pain, focal neurologic symptoms, leg swelling, and testicular pain. Medication, substance-use, exposure, and family histories were unavailable in the supplied records. At presentation, his temperature was 36.8 °C, heart rate was 112 beats/min, blood pressure was 142/85 mmHg, and oxygen saturation was 97% on ambient air. He appeared comfortable and nontoxic. Examination showed small blanching palmar macules, more prominent on the left, and mild right paracervical or upper thoracic tenderness. His neck was supple, with full active movement and no documented meningismus. He was tachycardic, with no murmur or peripheral edema. His lungs were clear, and the neurologic examination was nonfocal. High-sensitivity cardiac troponin I (hs-cTnI) decreased from 4,181.6 to 3,250.7 pg/mL over 7 hours 8 minutes, a fall of 22.3%. All three available measurements remained markedly above the reported reference interval of 0.0-19.8 pg/mL. The supplied records did not identify the assay platform or confirm whether 19.8 pg/mL was its sex-specific 99th-percentile upper reference limit. B-type natriuretic peptide (BNP) was 11 pg/mL. Other findings included thrombocytopenia, mild hyponatremia, and mild hypokalemia (Table 1). Polymerase chain reaction testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/B was negative. Rapid plasma reagin (RPR) testing was nonreactive; the test timing and any accompanying treponemal result were unavailable. Chest radiography showed no acute process.