Thread by @Sthanu5

What is the diagnosis?

A 30-year-old woman

👉 4-month history of a rash on her back

👉 examination revealed multiple large, annular, hypopigmented, atrophic macules

👉with well-defined, erythematous, raised borders

👉 lesions were hairless, hypohidrotic, and anesthetic

👉 had developed at a slow and progressive pace

👉 no peripheral-nerve enlargement.

👉skin-biopsy specimen revealed

👉well-developed epithelioid granulomas, lymphocytes,

👉 Langerhans' cells surrounding neurovascular structures within the papillary dermis

Dermal nerves were swollen and destroyed.
♦️
No acid-fast bacilli were detected on modified Ziehl–Neelsen staining
♦️
On the basis of clinical and histologic findings, the condition

👉 diagnosed as tuberculoid leprosy.

The CF of leprosy depend on the nature of the host's immune response to infection with M. leprae

👉 range from lepromatous leprosy (uncontrolled replication with nerve damage from high-titer infection)

👉to tuberculoid leprosy (nerve and organ damage predominantly from the host granulomatous immune response).

👉had no known contact with anyone with leprosy,
♦️
She was treated with a 6-month course of rifampin and dapsone

👉with nearly complete clearing of the skin lesions.

Tuberculoid Leprosy

nejm.org/doi/full/10.10…

Classic clinical features of tuberculoid and lepromatous leprosy

researchgate.net/figure/Classic…