Hansen disease

Question 1

Etiology

Answer 1

Mycobacterium leprae

Question 2

age

Answer 2

Child hood or adulthood

Question 3

Sites of infection

Answer 3

Skin, peripheral nervous system, upper respiratory tract, eyes, and testes.

Question 4

Classification

Answer 4

■ Tuberculoid (TL): Localized skin involvement and/or peripheral nerve involvement; few organisms.
■ Lepromatous (LL): Generalized involvement including skin, upper respiratory mucous membrane, reticuloendothelial system, adrenal glands, and testes; many bacilli.
■ Borderline (or “dimorphic”) (BL): Has features of both L and LL. Usually many
bacilli present, varied skin lesions: macules,
plaques; progresses to L or regresses to LL

Question 5

M leprae reproduces optimally at what temp?

Answer 5

Obligate intracellular acid- fast bacillus; reproduces optimally at 27
to 30°C.

Question 6

Main reservoir of M leprae

Answer 6

Humans are main reservoir of M.leprae.Wild armadillos (southern United States) as well as mang-
abey monkeys and chimpanzees are naturally infected with M. leprae; armadillos can develop lepromatous lesions

Question 7

Incidence and prevalence peak.

gender

Answer 7

Incidence rate peaks at 10 to 20 years; prevalence peaks at 30to50 years

male

Question 8

Transmission

Answer 8

Person to person in respiratory droplets

Question 9

Order of decreasing resistance in tuberculoid to lepromatous

Answer 9

■

In order of decreasing resistance, the spectrum is TT, BT , BB, BL, and LL

Question 10

Lepra type 1 and 2. lesions

Answer 10

Lepra Type 1 Reactions. Acute or insidious tenderness and pain along affected nerve(s), associated with loss of function.

Lepra Type 2 Reactions. Erythema nodosum leprosum (ENL)

Question 11

Incubation period

Answer 11

Incubation period is 2to40 years(most commonly 5 to 7 years

Question 12

Tuberculous leprosy skin lesions

Answer 12

few well defined hypopogmented hypesthetic macules. w raised edges.

trunk. Erythematous or purple border and hypopigmented center.Sharply defined, raised;often annular;enlarge peripherally. Central area becomes atrophic or depressed. Advanced lesions are anesthetic,devoid of skin appendages(sweatglandsorhair follicles).Any site including the face.

TT:Lesionsmayresolve spontaneously; not associated with lepra reac- tions.

BT:Does not heals pontaneously ;type1 lepra reactions may occur.

Nerve Involvement: May be a thickened nerve on the edge of the lesion;large peripheral nerve enlargement frequent(ulnar,posteriorauricu- lar,peroneal,andposteriortibialnerves ).Skin involvement is absent in neural leprosy

Question 13

Lesions in borderline leprosy

Answer 13

BORDERLINEBB LEPROSY Lesions are intermedi- ate between tuberculoid and lepromatous and are composed of macules,papules,andplaques .Anesthesia and decreased sweat- ing are prominent in the lesions

Question 14

Lepromatous leprosy skin lesions

Answer 14

LEPROMATOUSLEPROSY(LL,BL) Skin-colored
or slightly erythematous papules or nod- ules. Lesions enlarge; new lesions occur and coalesce.Later,symmetricallydistributed nodules,raisedplaques,di usedermalin l- trate,whichonthe aceresultsinlosso hair (lateral eyebrows and eyelashes) and leonine
acies(lion’s ace;Fig.25-66).Difuseleproma- tosis, occurring in western Mexico, Caribbean, presentsasdi usedermalin ltrationand thickened dermis. Bilaterally symmetric involv- ingtheearlobes, ace,arms,andbuttocks,or less requentlythetrunkandlowerextremities.
Lepra Type 1 Reactions: Skin lesions become acutelyin amed,associatedwithedemaand pain; may ulcerate. Edema is most severe on the ace,hands,and eet.
LepraType2Reactions(ENL):Presentas painulredskinnodulesarisingsuper cially and deeply. In contrast the tru erythema nodo- sumlesions ormabscessesorulcerate;they occur most commonly on the ace and extensor limbs.
LucioReaction:Occursinpatients rom MexicoorCaribbeanwithdi useLL.Presents asirregularlyshapederythematousplaques; lesions may resolve spontaneously or undergo necrosiswithulceration.
GeneralFindings
Extremities: Sensory neuropathy, plantar ulcers, secondaryinection;ulnarandperonealpalsies (Fig.25-67),Charcotjoints.Squamouscell carcinoma can arise in chronic oot ulcers
(Fig. 11-13).
Nose: Chronic nasal congestion, epistaxis;
destruction o cartilage with saddle-nose de or- mity (Fig. 25-67).
Eyes: Cranial nerve palsies, lagophthalmos, andcornealinsensitivity.InLL,anteriorcham- bercanbeinvadedwithuveitis,glaucoma,and cataract ormation.Cornealdamagecanoccur
ongue: Nodules, plaques, or ssures.
Nerve Involvement: More extensive than in Other Involvement: Upper respiratory tract,
anterior chamber o eye, and testes.

Question 15

Reactional states

Answer 15

Lepra Type 1 Reactions: Skin lesions become acutely inflamed,associated with edema and pain; may ulcerate. Edema is most severe on the face,hands,and feet.

LepraType2 Reactions(ENL):Present as painful red skin nodules arising superficially and deeply. In contrast the tru erythema nodosum lesions or mabscessesorulcerate;they occur most commonly on the face and extensor limbs.

LucioReaction:Occurs in patients from Mexico or Caribbean with diffuse LL.Presents as irregularly shaped erythematous plaques; lesions may resolve spontaneously or undergo necrosis with ulceration

Question 16

Lab diagnostics

Answer 16

Slit skin smear
Zheil neelsen ( both ear lobes, elbows, knees, and active lesions)
PCr
culture mouse foot pad
Measure IgM antibodies to phenolic glycolipid-1 (PGL-1

Question 17

Dermatopathology

Answer 17

DERMATOPATHOLOGY shows epithelioid cell granulomas forming around dermal nerves; AFB are sparse or absent. LL shows an extensive cellular infiltrate separated from the epidermis by a narrow zone of normalcollagen. Skin appendages are destroyed. Macrophages are lled with M. leprae, having abundant foamy or vacuolated cytoplasm (lepra cells or Virchow cells).

Question 18

Treatment

Answer 18

■ Tuberculoid: Dapsone plus rifampin.

■ Lepromatous: Dapsone plus clofazimine plus rifampin