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Flashcards in Leprosy Deck (12):
1

What is leprosy?

Chronic curable
Infectious disease
Caused by Mycobacterium leprae
Affecting skin, peripheral nerves
Mucosa of URT and eye
Affecting all age groups, males>females

2nd most common cause of neuropathic ulcers in Sri Lanka after diabetes mellitus

2

How is leprosy transmitted?

Nasal droplet inhalation
Prolonged contact with skin abrasions

By multibacillary form

3

How is leprosy diagnosed?

Clinical features and suspicion

Positive slit skin smears

Skin biopsy

Nerve biopsy

Lepromin test + (tuberculoid)

4

What are the important features of Mycobacterium leprae?

Acid fast alcohol fast
Human pathogen
Can’t be cultured in vitro
Very slow growth rate (14 day doubling time)

5

What is the pathophysiology of leprosy?

Infection by nasal droplets

Genetic and immune susceptibility to infection determines host immune response

Hematogenous dissemination

Immune response is T cell mediated delayed type hypersensitivity

Years long incubation period

Infects Schwann cells, skin, testes, bone





6

How is leprosy clinically classified?

According to host cell mediated immune response causing different clinical presentations

Ridley and Jopling system

Paucibacillary tuberculoid leprosy if good immunity

Multibacillary lepromatous leprosy if poor immunity

TT BT BB BL LL

7

What are the clinical features of tuberculoid leprosy?

Not contagious
Lepromin +
Single lesion (up to 3) commonly on face
Asymmetrical

Well demarcated hypopigmented hairless anhydrotic hypoanesthetic macules

Thickened nerves near lesion

8

What are the clinical features of lepromatous leprosy?

Contagious
Lepromin negative

Multiple lesions in Face, limbs, buttocks
Symmetrical

Pupules/ nodules/ plaques/ macules not hypoanesthetic

Thickened peripheral nerves with glove and stocking anesthesia, trophic ulcers, paralysis

Nasal crusting, epistaxis, keratitis, infertility


9

What are the DDx for leprosy?

Tuberculoid
-
Vitiligo
Pityriasis alba
Pityriasis versicolor
Sarcoidosis
Granuloma annulare
Cutaneous lymphoma


Lepromatous
-
Leishmaniasis
Guttate psoriasis
Discoid lupus
Neurofibromatosis

10

What is the treatment for leprosy?

Multi drug therapy (MDT)
Dapsone WHITE
clofazimine BROWN
rifampicin RED

Tuberculoid 6 months
Rifampicin + dapsone

Rifampicin 600mg/month
Dapsone 100mg/day

Lepromatous 12 months
Rifampicin + clofazimine + dapsone

Rifampicin 600mg/month
Dapsone 100mg/day
Clofazimine 300mg/month and 50mg/day

Regimens are given for 4 weeks as blister packs

11

What are lepra reactions?

Acute episodes of inflammation during the chronic course of leprosy

Due to immune reactions on Mycobacterium antigens

Occur at any time(before during after treatment)

Two types

Type 1 LR from type IV hypersensitivity

Type 2 LR from type III hypersensitivity

Do not stop MDT

Treat with steroids and NSAIDs

12

What are the clinical features of lepra reactions?

Type 1
-
Occur in tuberculoid leprosy
Existing lesions flare up
Nerve dysfunction

Type 2
-
Occur in lepromatous leprosy
New ulcerating lesions
Less nerve dysfunction
Erythema nodosum on trunk and limbs
Systemic illness