Leprosy

 

Definition

 

Chronic granulomatous infection of skin & peripheral nerves by Mycobacterium Leprae

 

Epidemiology

 

Endemic in some tropical regions

Commonest cause of peripheral neuropathy worldwide

 

Microbiology

 

Acid-Fast bacilli

- Carbol Fuchsin stain

- unable to be grown on artificial media

 

Pathology

 

Virchow Cells

Vacuolated macrophages

Granuloma

 

Transmission

 

Definitive route of transmission has not been proven

- is likely to be respiratory similar to TB

- broken skin transmission reported

 

Clinical Findings

 

Insidious onset

 

Involves

- skin

- superficial nerves

- nose, pharynx & larynx 

- eyes

- testicles

 

Skin lesions

- pale anaesthetic macule 1-10 cm

- diffuse erythematous nodules 1-5 cm

- diffuse skin infiltration

 

Neurological disturbances

- nerve infiltration & thickening

- anaesthesia & paresthesia

- trophic ulcers & bone absorption

- short digits

- leonine Facies

- charcot joints

 

Types

 

1. Lepromatous Type

 

Progressive malignant course

- characterised by severely impaired cell-mediated immunity

- late symmetrical polyneuropathy

 

2. Tuberculoid Type

 

Non Progressive benign course

- characterised by vigorous cell-mediated response

- anaesthetic skin patches

- thickened nerves

 

Diagnosis

 

Bacilli seen in scrapings from skin or nasal mucosa

Culture Negative

 

Management

 

Sulphone & Rifampicin for ~ 2yrs