Mycobacterial Skin Infections

Question 1

best indicator to determine loss of protective sensation

Answer 1

• monofilament test, size 5, 10 g pressure

Question 2

laboratory exams for leprosy

Answer 2

slit skin smear, skin punch biopsy, afb smear

Question 3

etiology of leprosy

Answer 3

mycobacterium leprae

Question 4

incubation period of leprosy

Answer 4

• tuberculoid leprosy 5 years

- lepromatous disease 20 years

Question 5

sequelae of leprosy

Answer 5

read

Question 6

classification of leprosy

Answer 6

<5 lesions, BI <1 = paucibacillary

more/= 5 lesions, BI >2 = multibacillary

Question 7

spectrum of leprosy

Answer 7

PAUCIBACILLARY
TT polar tuberculoid
BT borderline tuberculoid leprosy

MULTIBACILLARY
BB borderline leprosy
BL borderline lepromatous leprosy
LL lepromatous leprosy

Question 8

what is polar tuberculoid leprosy (TT)

Answer 8

• strong cell mediated immunity
• primary lesion: plaque, often annular configuration
• borders are sharply marginated
• saucer shaped lesions
• usually solitary, firmly indurated, elevated, erythematous, scaly, dry, hairless, or hypopigmented

Question 9

what is borderline tuberculoid leprosy (BT)

Answer 9

• strong cell mediated immunity but host response is insufficient for self cure
• primary skin lesion: multiple asymmetric plaques and papules
• satellite lesions and pseudopods
• loss of sensation and nerve enlargement

Question 10

what is borderline leprosy (BB)

Answer 10

• short-lived
• primary lesion: annular large plaques with sharply marginated interior and exterior margins with islands of normal skin
• swiss cheese appearance
• nerves enlarged

Question 11

what is borderline lepromatous leprosy

Answer 11

• low cell mediated immunity but sufficient to induce tissue destructive inflammation
• hypoesthetic or anesthetic
• nerve trunk palsies

Question 12

primary lesion in borderline lepromatous leprosy (BL)

Answer 12

classic dimorphic lesion: annular configuration with poorly marginated outer border with sharply marginated inner one (MAMA MARY HALO)

Question 13

what is lepromatous leprosy

Answer 13

• lack cell mediated immunity = unrestricted bacillary replication
• wide dissemination, multi-organ

Question 14

lesions in lepromatous leprosy

Answer 14

• poorly defined, skin colored nodules
• symmetrically distributed
• diffuse dermal infiltration
• wide nasal roots and fusiform swelling of fingers

Question 15

t/f skin smear is a requirement to categorize patient

Answer 15

false, lesion involvement is used to categorize

Question 16

what’s in a pb blister pack

Answer 16

GREEN
once a month, day 1: 2 rifampicin, 1 dapsone
once a day, day 2-28: 1 dapsone
full course: 6 packs (6 mos)

Question 17

what’s in a mb blister pack

Answer 17

PINK
once a month, day 1: 2 rifampicin, 3 clofazimine, 1 dapsone
once a day, d 2-28: 1 clofazimine, 1 dapsone
full course: 12 packs (12 mos)

Question 18

means of spread of cutaneous tb

Answer 18

direct inoculation (tb verrucosa cutis, lupus vulgaris)

direct extension (scrofuloderma, miliary tb)

Question 19

what is tb verrucosa cutis

Answer 19

direct inoculation to the skin of a person who had been previously infected with m tuberculosis

Question 20

skin findings in tb verrucosa cutis

Answer 20

• purplish, brownish red warty growth

- sites: knees, elbows, hands, feet, buttocks

Question 21

skin findings in lupus vulgaris

Answer 21

• small, sharply defines, reddish brown lesions with gelatinous consistency
• apple jelly nodules

Question 22

skin findings of scrofulderma

Answer 22

• firm and painless lesion that ulcerate with granular base

- heals without treatment but can take years

Question 23

skin findings in miliary tb

Answer 23

• small, millet sized, red spots
• become ulcers and abscesses
• poor prognosis, seen in immunocompromised