Mycobacterial Skin Infections Flashcards
best indicator to determine loss of protective sensation
- monofilament test, size 5, 10 g pressure
laboratory exams for leprosy
slit skin smear, skin punch biopsy, afb smear
etiology of leprosy
mycobacterium leprae
incubation period of leprosy
- tuberculoid leprosy 5 years
- lepromatous disease 20 years
sequelae of leprosy
read
classification of leprosy
<5 lesions, BI <1 = paucibacillary
more/= 5 lesions, BI >2 = multibacillary
spectrum of leprosy
PAUCIBACILLARY
TT polar tuberculoid
BT borderline tuberculoid leprosy
MULTIBACILLARY
BB borderline leprosy
BL borderline lepromatous leprosy
LL lepromatous leprosy
what is polar tuberculoid leprosy (TT)
- 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
what is borderline tuberculoid leprosy (BT)
- 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
what is borderline leprosy (BB)
- short-lived
- primary lesion: annular large plaques with sharply marginated interior and exterior margins with islands of normal skin
- swiss cheese appearance
- nerves enlarged
what is borderline lepromatous leprosy
- low cell mediated immunity but sufficient to induce tissue destructive inflammation
- hypoesthetic or anesthetic
- nerve trunk palsies
primary lesion in borderline lepromatous leprosy (BL)
classic dimorphic lesion: annular configuration with poorly marginated outer border with sharply marginated inner one (MAMA MARY HALO)
what is lepromatous leprosy
- lack cell mediated immunity = unrestricted bacillary replication
- wide dissemination, multi-organ
lesions in lepromatous leprosy
- poorly defined, skin colored nodules
- symmetrically distributed
- diffuse dermal infiltration
- wide nasal roots and fusiform swelling of fingers
t/f skin smear is a requirement to categorize patient
false, lesion involvement is used to categorize
what’s in a pb blister pack
GREEN
once a month, day 1: 2 rifampicin, 1 dapsone
once a day, day 2-28: 1 dapsone
full course: 6 packs (6 mos)
what’s in a mb blister pack
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)
means of spread of cutaneous tb
direct inoculation (tb verrucosa cutis, lupus vulgaris)
direct extension (scrofuloderma, miliary tb)
what is tb verrucosa cutis
direct inoculation to the skin of a person who had been previously infected with m tuberculosis
skin findings in tb verrucosa cutis
- purplish, brownish red warty growth
- sites: knees, elbows, hands, feet, buttocks
skin findings in lupus vulgaris
- small, sharply defines, reddish brown lesions with gelatinous consistency
- apple jelly nodules
skin findings of scrofulderma
- firm and painless lesion that ulcerate with granular base
- heals without treatment but can take years
skin findings in miliary tb
- small, millet sized, red spots
- become ulcers and abscesses
- poor prognosis, seen in immunocompromised
