MRCP2-0934

MRCP2-0934

A 32-year-old woman from Brazil, who has been studying abroad in the United States, presents to the Dermatology Clinic with multiple hypopigmented lesions on her arms and legs. She reports decreased sensation within these areas and tenderness upon palpation of the superficial nerves. Additionally, she has a non-painful ulcer on her foot. Laboratory results show:
– Hemoglobin (Hb): 130 g/L (normal range: 120-160 g/L)
– White blood cell count (WBC): 7.2 x 10^9/L (normal range: 4.0-11.0 x 10^9/L)
– Platelets: 220 x 10^9/L (normal range: 150-400 x 10^9/L)
– Sodium (Na+): 142 mmol/L (normal range: 135-145 mmol/L)
– Potassium (K+): 4.2 mmol/L (normal range: 3.5-5.0 mmol/L)
– Creatinine (Cr): 90 umol/L (normal range: 50-120 umol/L)

What is the most useful test to confirm the diagnosis?