Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Dermatology PPT 4 Cutaneous Tuberculosis Lecture Notes
CUTANEOUS
TUBERCULOSIS
ETIOLOGY- Mycobacterium Tuberculosis
PATHOGENESIS- manifestations of lesions depend
on
1.Immunity of the host
Specific immunity to M. Tuberculosis ? depending
on whether exposure to the bacteria is primary or
secondary
General immunity of the host
2. Route of entry
3. Bacterial load
CLASSIFICATION
1.Exogeneous source
Tuberculous chancre
Warty tuberculosis/ TVC
Lupus vulgaris
2.Endogenous source
a. contiguous source ? Scrofuloderma
b. auto-inoculation ? Oroficial T.B.
c. hematogenous - Lupus vulgaris,
Tuberculous gumma
3.Tuberculides ?
a. Micropapular ? Lichen scrofulosorum
b. Papular, Papulo-necrotic
c. Nodular? Erythema nodosum
Erythema induratum(Bazin)
Tuberculous Chancre
No prior immunity to M. tuberculosis
( Primary complex in the skin)
Entry?cuts, abrasion, insect bites, wounds
Site- exposed areas of limbs, face
Age - children
Clinical feature
Nodule ulcerates
producing tuberculous
chancre
Crusts form and edges
become indurated
Regional
lymphadenopathy in
few weeks
Dev. Of immunity
lesion heal to produce
a scar
Warty Tuberculosis/ Tuberculosis Verrucosa
Cutis
Exogenous source
Moderate to high immunity to M.
tuberculosis
Occupational- who handle tuberculous
tissue eg. butcher, pathologist,
veterinarians (anatomist wart)
Site ? hands, feet
Single indolent
verrucous nodule or
plaque with a
serpenginous border,
indurated base, centre
may show scarring.
Heals in several
months leaving thin
atrophic scar
Lymphadenopathy rare
Scrofuloderma/ Tuberculosis Cutis
Colliquativa
Develops as an extension of an underlying
focus ? lymph node or bone
Site ? cervical region common with
infected cervical lymph nodes breaking
down into the skin
Infected lymph nodes
become inflamed,
swollen, get fixed to
overlying bluish skin
Breakdown of lymph
nodes formation of
ulcers with undermined
edge
AFB can be
demonstrated
Orificial Tuberculosis/ Tuberculosis Cutis
Orificialis
Develops from auto inoculation around the
muco cutaneous junctions in patients with
internal tuberculosis
Site- lips, mouth in pulmonary T.B.
anal region in intestinal T.B
external genitalia in genitourinary T.B
Host immunity poor with active internal
disease.
Small erythematous
nodules break
down, form round,
shallow, granulating
ulcers covered by
thin crust.
Painful
No tendency to heal
without effective
treatment
Tuberculin test may
be -ve
Lupus Vulgaris
most common form of cut. TB
Usually acquired from an external source;
rarely from haematogenous dissemination
Site ? around nose (nasal mucosa and
lips) and face in western countries
buttocks, thighs, legs in India
Initial lesion is a soft erythematous nodule
Slowly several such nodules coaslesce to
form a soft plaque which slowly extends
Presence of APPLE JELLY nodules at edge
of plaques- in diascopy( uncommon in
Indian skin)
MATCH STICK sign ? soft nodules can be
probed or pierced with a match skick
Diseases relentlessly progresses with
irregular extension of the plaque
Healing occurs with SCARRING
Occasional ulceration, crusting and
scarring with destruction of underlying
tissues and cartilage- ULCERATIVE and
MUTILATING form
Tuberculous Gumma
Results hematogenous dissemination from
a tubercular focus
Usual in malnourished children
The lesion is initially a subcutaneous
nodule which breaks into the skin to form
an ulcer with an undermined edges.
TUBERCULIDES
Symmetrical eruptions
Result of internal focus of tuberculosis,
though internal disease may not be active.
Patient health is good.
Prob. Cause hematogenous dissemination of
bacilli in a person with high degree of
immunity
Tuberculin test always +ve
Cured by ATT
Lichen Scrofulosorum
Tiny<5mm,
perifollicular,
lichenoid papules
Asymptomatic
Site ? trunk
Involute after many
months without scars
Tuberculin test ?
strongly +ve
Papulonecrotic Tuberculides
Crops of deep seated papules and nodules
Lesions are capped by pustules; ulcerate
forming crusts
Heal in a few months with scar
New crops keep developing
Asymptomatic
Tuberculin test strongly +ve
Erythema Nodosum
Crops of indurated very tender,
erythematous deep seated nodules,
which evolve from red to violaceous to
yellow
Inspection ? bruise, palpation nodule
Never ulcerates; heal without scarring
Site ? bilateral shins
Constitutional- fever, malaise
Tuberculin test +ve
Course-
spontaneous
resolution in 6
weeks
Histology ? septal
pannicullitis no
vasculitis
Erythema Induratum
Site- calves in young adult females
Bilaterally symmetrical
Initial develop in cold weather
Subcutaneous nodules and plaques
with gradually involve the overlying
skin with ulceration
Tuberculin test
+ve
Ulcers heal
leaving atrophic
scars
Chronic ,
recurrrent
Histological ?
nodular vasculitis
Investigations
To confirm tuberculosis
A. Biopsy ? caseating granuloma
B. Isolation of M.tuberculosis ?
1.culture of AFB from pus, skin
biopsy specimen
2. PCR
C. Mantoux test
To rule out concomittant tuberculosis
in other organs
1. CXR
2. X-ray joint, bones
3. FNAC ? of enlarged lymph nodes
Differential diagnosis
lupus vulgaris- leishmaniasis, sarcoidosis,
systemic fungal infection, SCC
tuberculosis verrucosa cutis - warts
TREATMENT
Standard ATT
Intensive phase ? isoniazid 5mg/kg
For 2 months rifampicin 10mg/ kg
ethambutol 15mg/ kg
pyrazinamide 20mg/kg
Continuous phase - isoniazid 5mg/kg
For 4 months rifampicin 10mg/ kg
Extension ? max. 8 months
THANK YOU
This post was last modified on 07 April 2022