Cutaneous tuberculosis
Epidemiology

Cutaneous tuberculosis occurs worldwide;
incidence of different forms varies globally.

India: Affected 2% of all skin outpatients (1950s and
1960s) and then 0.1% by 1980s; due to the
availability of effective drugs and improvement in
the living standards.

In India, scrofuloderma is common in children; lupus
vulgaris commonest in adults.

Resurgence in tuberculosis, and consequently in
cutaneous tuberculosis; due to the HIV pandemic,
resistant strains of M. tuberculosis, use of
immunosuppressive therapy, ease of global travel
and migration, poverty, malnutrition.
Aetiology

Caused by M. tuberculosis, M. bovis and under
certain conditions, the bacillus Calmette-Guérin
(BCG), an attenuated strain of M. bovis.

M. tuberculosis and M. bovis cause identical
skin manifestations in humans.

In HIV-infected individuals, even atypical
saprophytic strains of Mycobacterium may
cause infection and bizarre forms of disease.
Cutaneous tuberculosis

Spectrum of cutaneous changes induced by
M. tuberculosis depend upon:
◦ Route of infection
◦ Immunological state of the host

Mere presence of mycobacteria in the skin does
not lead to the clinical disease.
Routes of infection
Exogenous
◦ From an external source, through breach in
the skin at the site of trauma.
 Endogenous
◦ Through contiguous involvement of skin
◦ Through lymphatic spread
◦ Through haematogenous dissemination


Autoinoculation
Classification (Modified from Beyt et al.)
 Inoculation
tuberculosis (exogenous
source)
 Secondary tuberculosis (endogenous
source)
 Haematogenous tuberculosis
 Eruptive tuberculosis (tuberculides)
Classification (Modified from Beyt et al.)
 Inoculation
tuberculosis (exogenous
source)
◦ Tuberculosis chancre
◦ Warty tuberculosis (verrucosa cutis)
◦ Lupus vulgaris (some)
Classification (Modified from Beyt et al.)
 Secondary
tuberculosis (endogenous
source)
◦ Contiguous spread: Scrofuloderma
◦ Auto-inoculation: Orificial tuberculosis
Classification (Modified from Beyt et al.)
 Haematogenous
tuberculosis
◦ Acute miliary tuberculosis
◦ Lupus vulgaris (some)
◦ Tuberculous gumma
Classification (Modified from Beyt et al.)
 Eruptive
tuberculosis (tuberculides)
◦ Micropapular
 Lichen scrofulosorum
◦ Papular
 Papular or papulonecrotic tuberculide
◦ Nodular
 Erythema induratum (Bazin)
 Nodular tuberculide
 Erythema nodosum
Tuberculous chancre
Occurs following M. tuberculosis inoculation
through breach in the skin of an individual, not
previously infected with tuberculosis.
 Initially, a small papule, scab, nodule or a
poorly healing wound; gradually forms a
painless ulcer with a shallow, granular or
haemorrhagic base and undermined edges.
 Spontaneous healing within 3 to 12 months,
with atrophic scar and often, calcified nodes.

Warty tuberculosis
(Syn: Tuberculosis verrucosa cutis
Pathogenesis
 Previously infected individual with moderate or
high immunity
 Accidental superinfection from exogenous
sources: physician, pathologists
 Autoinoculation with sputum
 Common sites
◦ Adults - fingers and hands
◦ Children - ankles and buttocks
Warty tuberculosis
Clinical features
Small, solitary, indurated, red or brown, papule or
nodule
Verrucous plaque (finger-like projections; fissured
surface)
Spontaneous involution with atrophic scarring
Regional lymph nodes may enlarge due to
secondary bacterial infection.
Warty tuberculosis
Course
 Verrucous lesions persist; but seldom ulcerate.
 Lesions run a chronic course, and if untreated,
remain inactive for months or years.
 Lesions may involute spontaneously, resulting in
sunken, atrophic scars.
Warty tuberculosis
Differential diagnosis
 Common warts
 Hypertrophic lichen planus
 Verrucous epidermal nevus
 Blastomycosis
 Chromomycosis
 Actinomycosis
Lupus vulgaris
Pathogenesis
 Most common form of cutaneous tuberculosis
 Occurs in sensitized individuals with moderate
to high immunity
 Affects all age groups
Lupus vulgaris
Pathogenesis
 Lesions arise by:
◦ Haematogenous dissemination
◦ Lymphatic spread
◦ Contiguous spread from tuberculous tissue
◦ Exogenous inoculation
Lupus vulgaris
Clinical features
Small, solitary reddish-brown nodule
Plaque
Elevated, infiltrated, deep brown in colour
Slowly expands at one end; heals with scarring at
the other end
Asymptomatic lesions, commonly affects the
buttocks and trunk
Lupus vulgaris
Clinical forms
 Plaque forms
 Ulcerative and mutilating forms
 Vegetating forms
 Tumor-like forms
 Papular and nodular forms
Lupus vulgaris
Course
 Chronic, indolent course over years, if left
untreated.
 Lesions undergo ulceration, and superficial
scarring.
 Characteristically thin, white, smooth scars; may
break down or become keloidal.
 Complications comprise scarring, contractures,
tissue destruction, development of squamous
cell carcinoma in the scars (8%).
Lupus vulgaris
Differential Diagnosis
 Borderline tuberculoid leprosy
 Psoriasis
 Sarcoidosis
 Discoid lupus erythematosus
 Syphilitic gumma
 Deep fungal infections
Scrofuloderma
Pathogenesis
 Contiguous involvement of the skin overlying a
tuberculous focus, usually a lymph node, an
infected bone or joint or epididymis.
 Common in children, adolescents and aged;
may affect all age groups.
 Usually affects the face and neck, often
bilaterally.
 Commonly involves the cervical, parotid,
submandibular and supraclavicular lymph
nodes; less commonly, axillary and inguinal.
Scrofuloderma
Clinical features
Initially, a firm, subcutaneous nodule, fixed to the
overlying skin
Cold abscess formation
Secondary ulceration, sinus tract formation
Ulcer has undermined edges and granulating floors
Scrofuloderma
Course
 Numerous sinus tracts and fistulae develop over
a period of several months.
 Spontaneous healing may occur, with puckered
and cord-like scars.
 Scar tracts characteristically bridge the areas of
ulceration or even normal skin.
Scrofuloderma
Differential Diagnosis
 Atypical mycobacterial infection
 Lymphogranuloma venereum
 Actinomycosis
 Sporotrichosis
 Syphilitic gummas
 Acne conglobata
 Hidradenitis suppurativa
 A rare form of tuberculosis of the mucous
membranes and skin adjoining the orifices.
 Presents as a nodule which ulcerates with
undermined edges
Orificial tuberculosis

A rare form of tuberculosis of the mucous
membrane and skin adjoining the orifices

Presents as a nodule which ulcerates with
undermined edges
Orificial tuberculosis
Site affected depends on the site of internal
tuberculosis:
◦ Pulmonary tuberculosis: mouth
◦ Tuberculosis of pharynx, larynx: lips
◦ Intestinal tuberculosis: external genitalia;
anus; perianal
◦ Genitourinary tuberculosis in women: vulva
 Prognosis: poor due to advanced internal
disease and compromised immunity.

Acute miliary tuberculosis of the skin
Rare manifestation of fulminating tuberculosis
due to haematogenous dissemination of
mycobacteria into the skin, from a meningeal or
pulmonary focus.
 Crops of numerous, minute, erythematous to
bluish, macules, papules, vesicles, pustules or
purpuric lesions occur on all parts of the body,
especially the trunk.
 Usually occurs in infants, young children or
immunosuppressed patients, co-existing HIV
infection, measles.

Tuberculous gumma
Haematogenous dissemination of mycobacteria
from a primary tuberculous focus, during
periods of lowered resistance.
 Commonly involves the trunk, extremities or
head.
 Lesions arise as a single or multiple, firm
subcutaneous nodule or fluctuant abscesses.
 Ulcers with undermined edges, sinuses and
fistulae may occur
 Healing occurs with cord-like and puckered
scarring.

Tuberculides
Occur as a hypersensitivity reaction to
 M. tuberculosis or its products in a patient with
moderate to high immunity, following
haematogenous spread of the mycobacteria.
 Salient features:
◦ A positive tuberculin test
◦ Evidence of obvious or past tuberculosis
◦ A positive response to anti- tuberculous therapy

Tuberculides
Types
 Micropapular: lichen scrofulosorum
 Papular: papulonecrotic tuberculide
 Nodular: Erythema induratum of Bazin
Erythema nodosum
Erythema induratum of Bazin
(Nodular tuberculide)
A chronic, recurrent, nodular and ulcerative
disorder
 Commonly affects young, or middle-aged, obese
women; men affected occasionally
 Predominantly affects calves; may also occur on
upper limbs, thighs, buttocks and trunk
 The nodules run an indolent course and form
ulcers
 Ulcers are ragged, irregular and shallow, with
bluish edge

Diagnosis
Absolute diagnosis established by:
 A positive culture of M. tuberculosis from the
lesion
 Identification of mycobacterial DNA by
Polymerase Chain Reaction (PCR) technique
Other diagnostic criteria
The diagnosis is suggested by:
 Clinical history and physical signs
 A positive reaction to tuberculin
 Demonstration of tuberculoid granuloma on
histolopathology
 Demonstration of acid-fast bacilli in the lesion
 Presence of culture-proven active tuberculous
focus elsewhere in the body
 Effect of specific therapy
Cutaneous tuberculosis treatment
General principles

Notification

Identification and treatment of the underlying
tuberculous focus

Identification and treatment of co-existent
infections such as HIV

Specific chemotherapy

Ancillary measures
Cutaneous tuberculosis
Drug regimen
The standard regimens comprise:
 Initial intensive phase (Phase I)
Rapidly destroys large populations of multiplying
mycobacteria.
Continuation phase (Phase II)
Eliminates persistent dormant organisms.

Drug therapy: 6 months regimen (for adults)
1. Rifampicin 450mg/600mg (wt </> 50kgs) - 6
months
2. Isoniazid (300mg daily) - 6months (add
pyridoxine 10mg/day)
3. Pyrazinamide - for 1st 2months
1.5gm daily for patient <50 kg
2gm daily for patient >50 kg
4. Ethambutol for the 1st 2 months
Dose: 15mg/kg body weight daily
All drugs taken on empty stomach once daily
Re-introduction of AKT following drug
reactions (WHO)
Drugs
D1
D2
D3
INH
(Least)
50mg
300mg
300mg
Rcin
75mg
300mg
Full
PZA
250mg
1mg
Full
ETB
100mg
500mg
Full
SM
(Highest)
125mg
500mg
Full
If severe reactions, start with smaller dosage (1/10th)
Revised National Tuberculosis
Control Programme (RNTCP)
Extra-pulmonary tuberculosis: Diagnosis
One culture-positive specimen from extrapulmonary
site, or
Histological evidence, or
Strong clinical evidence consistent with active
extrapulmonary TB
Revised National Tuberculosis
Control Programme (RNTCP)
Cutaneous TB:
Category III (sputum smear negative)
Regimen: 2(HRZ)3 + 4(HR)3
Category II (sputum smear positive)
2(HRZES)3 + 1(HRZE)3 + 5(HRE)3
Cutaneous tuberculosis treatment
Special considerations
 Surgical intervention coupled with AKT in
scrofuloderma; small lesions of lupus vulgaris;
tuberculosis verrucosa cutis.



Plastic Surgery in cases of disfigurement due to
lupus vulgaris
Standard regimens: effective in HIV-positive.
HIV-infected individuals: higher drug reaction and
infection rates.
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