(BMJ)—In India, a 50-yo man presented w/ a 2-yr hx of hypopigmented patches on the trunk and limbs. Exam: variable-sized patches w/ central clearing; sparse hair and sensation loss over some lesions. Mild weakness but no sensory loss in distribution of ulnar, lateral popliteal, and posterior tibial nerves. What is the dx?
Leprosy
Pityriasis alba
Tuberculosis verrucosa cutis
Neurofibromatosis type 1
Tinea versicolor
You are correct. Leprosy was diagnosed via bx and slit-skin smear that was positive for acid-fast bacilli. According to WHO, a leprosy dx can be made if ≥1 of the following cardinal signs is present: definite loss of sensation in a hypopigmented or reddish skin patch; a thickened peripheral nerve w/ loss of sensation and/or weakness of muscles supplied by the peripheral nerve; and/or the presence of acid-fast bacilli in a slit-skin smear. Standard adult tx for multibacillary leprosy consists of rifampin, clofazimine, and dapsone once per month, followed by clofazimine and dapsone daily x28 days. Total tx duration is 12mo. Leprosy should be considered an important DDx, even in low-incidence countries, as new case detection is on the increase globally. Early detection and tx prevent transmission, disabilities, and deformities.

BMJ 2017;358:j4234