I- DEFINITION :
- TB is the & rsquo; all dermatologic manifestations due to the presence of tubercle bacilli in the & rsquo; organization and particularly of the skin.
II- EPIDEMIOLOGY :
1- FREQUENCY :
– rare in Europe and the industrialized countries, this is due to :
– L & rsquo; improving living conditions, Hygiene, and nutrition.
– Immunization and tuberculosis chemotherapy.
– in Algeria, TB is a public health problem, Sevie that in & rsquo; endemic.
2- PATHOGEN :
– Koch's bacillus (BK) is a mycobacterium, immobile, very heat sensitive but resistant to cold and desiccation,
– colored red by the fuchsin, not decolorized by nitric acid or alcohol (acid-fast bacillus [BAAR]).
– It is cultivated in strict aerobic between 35 ° C and 37 C on enriched media " Lowenstein Jensen » – On distingue:
– Tuberculosis is on bacille de Koch,
– Mycobacterium tuberculosis bovis, agent of bovine tuberculosis (involved in 1 at 5% cases of human tuberculosis).
III- CLASSIFICATION :
Classification of cutaneous tuberculosis according beyt :based on pathophysiological criteria
I- TB inoculation (exogenously) :
– canker tuberculosis
– warty tuberculosis
II- secondary tuberculosis (endogenous) :
– Par contiguïté : Scrofuloderme
– Auto-inoculation: orificial tuberculosis
III- hematogenous tuberculosis :
– lupus vulgaris
– Acute miliary tuberculosis
– TB gum
IV- eruptive tuberculosis :
– Lichen scrofulosorum
– Tuberculides papular or papulopustular necrotic
– Erythema induratum
– nodular vasculitis
I- TB inoculation (exogenously) :
1- canker tuberculosis ; mutibacillaire form
- Secondary inoculation mucocutaneous bacillus directly in a non-immunized subject :
- Especially in infants and young children
- After infecting a direct injury: circumcision, traditional surgery, pierced ear, there is rarely a dirty wound (bites,coughing)
- predominates in the lower limbs, face and mucous orogenital.
- Incubation :1at 3 weeks
- érythématoviolacé a firm nodule, that ulcer with peeling edges and complicated, and 1à 2 month, lymphangitis lymphadenopathy with poly satellite fistulized evolution
- No general signs
- Evolution :Sometimes extension spontaneous cure TB to other organs
- IDR negative
- Ex Direct and cultures allow to find the BK
- histology found a nonspecific inflammatory infiltrate rich in neutrophils , AFB, granulomatous evolution occurs only after lymph node involvement.
2- The warty tuberculosis : pauci bacillary form,infrequent
- it results either :
- re-inoculation of Mycobacterium tuberculosis in a previously sensitized subject,
- Inoculation is often accidental professional : cattle breeders, slaughterhouse workers, paramedic medical staff.
- Horny hard nodule which gradually spread to form a warty very limited closet surrounded by an inflammatory areola where deaf pus
- Siege : hands (bord radial)++,dorsal side of the fingers / wrist ,peri region anal and the buttocks and the point of inoculation.
- signs Related :adénopathies satellites , tuberculous lymphangitis,achievement of tendons, bones and joints underlying.
- Evolution slow and torpid
- In the absence of treatment : swarming near and distance
- IDR is positive
- Exam Direct and cultures often negative
– tuberculoid granuloma with caseating
– acanthosis and papillomatosis
– hyperkératose orthokératosique
- Diagnostic differential :cutaneous leishmaniasis, pyodermites, mycoses,verrues.
II. secondary tuberculosis (endogenous) :
1- Le scrofuloderme : F .multibacillaire
- Is over 50% of all cutaneous TBC
- Secondary to the extension to the skin of adenitis or osteo arthritis to tuberculosis
- Seat : cou, trunk, members, rachis
- These are nodules dermo-hypodermic, progressing to softening, fistula to the skin and the & rsquo; ulceration, and healing
- IDR :positive
- We find the BK culture of the aspirate of the abscess because the former is generally unprofitable Direct
- The radiological and biological explorations allow to find the initial focus.
- histology feature : follicle tuberculoïde Koester with caseating retouve is at the stage of nodule and softening
2- The orificial tuberculosis : F paucibacillaire
- Secondary to self-inoculation from pulmonary homes, laryngeal, digestive and urinary.
- Touche especially the man with fireplace evolutionary visceral
- periorificial ulcerations subacute (the language , the lips, nostrils, anus, urethra)
- Ulcer typical TB language : single superficial ulceration , not hardened and not infiltrated with irregular edges ,the bottom is fibrin purulent ,painful ++.
- signs Related : polyADP inflammatory ipsilateral.
- evolution : No spontaneous tendency to healing, often with appearance small abrasions coalescing devices.
- IDR :positive
- Cultures :positives
- Histology initially nonspecific inflammatory infiltrate with presence B.A.A.R., then form a pseudo-epitheliomatous hyperplasia.
- Diagnostic differential : with sores, plates mucosa of secondary syphilis, squamous cell carcinoma.
III- TB bloodborne :
a)- lupus tubercular :
- Pauci bacillary form common
- Liée to a reactivation of a quiescent or tuberculose viscérale rare évolutive
- seat : 80% face,cou,ears,rare on members
- Built reddish or yellowish, soft embossed squamous which slowly spreads with rugged , formed by the confluence of lupomes- micronodules dermal- having a yellowish aspect vitropression the so-called "apple jelly"
- The evolution is slow with ulcerations,atrophic scarring and fibrous with scalable purplish edges
- A long-term extension can give mutilation or squamous cell degeneration
- IDR positive
- histology agglomeration of tuberculoid granulomas
- examination direct and the culture are often negative
- Diagnostic differential :with sarcoidosis, cutaneous leishmaniasis, tertiary syphilis
b)- The tuberculosis miliary acute :
- it results either:
- a spread through blood from a visceral focus mostly pulmonary or
- Occurs during a primary infection in immunocompromised patients severe
- children malnourished, elderly people
- papules bluish ,hemorrhagic vesicles scattered necrotic
- Impaired general condition
- Frequently associated with pulmonary miliary, meningeal
- Fundus :retinal tubers Bouchut
- IDR negative
- Ex Direct found BK
- The evolution is often fatal
c)- The tires tubercular :
gums tubercular :
- terrain : immunodéprimé, malnourished.
- seat : especially the lower limbs.
- aspect : cold abscess or nodules dermohypodermiques farms which soften, then ulcerate.
- Evolution is slow(several months) to a fibrous scar
- bacteriological tests(Ziehl-Neelsen et culture) BK may objectify.
- histology : tuberculoïde the follicle Koëster is found before the stage of ulceration.
IV- eruptive tuberculosis :
Cutaneous manifestations involving immunological phenomena
1- Lichen scrofulosum
- Rare, child
- Micro pink papules, farms, shiny granites fall into closets
- Trunk, members, upper lips
- IDR +++
2- Tuberculides papulo nécrotique
- Dark red papules, dures, sometimes pustules or necrotic places.
- Faces extension members, dorsal hands, feet, buttocks, the lumbar region.
- always positive IDRT.
- histology : tuberculoid granuloma with caseating.
- always negative bacteriology.
- Differential diagnosis : with necrotic acne, syphilides necrotic, prurigo, furoncles.
3- Erythema induratum
- Pushed asymmetric predominant hypodermitis the lower limbs
- Predominates in obese women with venous insufficiency
- Inflammatory nodules or cupboards purplish and painful with a chronic course
- IDR ++++
4- erythema nodosum
- Manifestation of primary TB infection
- Hypodermitis acute nodular, performing hot red painful inflammatory nodules
- Faces of leg extensions
- Fever, arthralgia and impaired general condition
V- cutaneous manifestations of BCG :
On the BCG website can be
- Ulceration not healing after several months of evolution
- pustular reaction
- Nodule subcutaneous abscess progressing to
- Rarely diffuse protests :tuberculides papulonecrotiques,IN,vascularite nodulaires
IV- POSITIVE ELEMENTS OF DIAGNOSIS :
– it is held on a d & rsquo beam; arguments.
1/ elements presumption :
– Concept with tuberculosis.
– history or coexistence visceral tubercular lesions.
* biology :
– FNS : leukocytosis with hyper lymphocytosis.
– IDR : tuberculin, uses of the purified tuberculin
– injection 10 IU intradermal tuberculin, on the face of the ant & rsquo; forearm.
– after reading 72 h, by measuring the diameter of the & rsquo; induration
2/ items certainties :
A- bacteriological :
– c & rsquo; is the highlight BK.
– sampling : on skin cheesy home, puncture d & rsquo; lymphadenopathy, biopsy specimen , serosities.
1- DIRECT EXAMINATION : after staining ZIEL NELSEN, the AFB
2- CULTURE on the middle of Lovenstein
– For the identification of the species and the development of antibiotic susceptibility :
– the multiplication of tubercle bacilli (time division = 20 hours) imposing a culture of delay means 28 days, and 42 days.
B- histology :
– The characteristic histological element but not specific for tuberculosis is the follicle Koester
C- genetic amplification methods ” PCR” :
– their interest is in paucibacillary forms as lupus vulgaris, or the reaction conditions (erythema, endure pools), but however it lacks specificity and sensitivity,
WE- THE TREATMENT :
Chemotherapy anti tuberculous (Rifampicine,Isoniaside,Ethambutol,Pyrazinamide)
- Triple for 2 month
- Double for 4 month
- Depends on the clinical form
- Oral TB must be given as a single morning dose on an empty stomach 1 / 2heure before breakfast.
- Patients who have a major side effect of one of the products may use separate molecules.
- The Rimifon only one dose 5 mg / kg / day for 6 months may be sufficient in the treatment of complications of BCG
VII- PROPHYLAXIE :
- It is based on the BCG vaccination, vaccine consisting of live attenuated bacilli,
- the early detection and treatment forms Multibacillary to prevent contagion,
- raising the socioeconomic globally for better conditions of hygiene and nutrition.