Medicinus – Cours de Médecine en ligne

Skin tuberculosis
(Last Updated On: 26 February 2020)




– rare in Europe and industrial countries, this is due to:

– Improving living conditions, hygiene, and nutrition.

– Vaccination and TB chemotherapy.

– in Algeria, tb is a public health problem that is endemic.


– Koch bacillus (BK) is a mycobacteria, immobile, very sensitive to heat but resistant to cold and desiccation,

– coloured red by fuchsin, not discoloured by nitric acid or alcohol (acid-alcoholic-resistant bacillus[BAAR]).

– It is grown in strict aerobics between 35 and 37 degrees Celsius on enriched environments "Lewenstein Jensen" – One distinguishes:

– Mycobacterium tuberculosis hominis or Koch bacillus,

– Mycobacterium tuberculosis bovis, an agent of bovine tuberculosis (involved in 1 to 5% of human TB cases).


BeYT classification of skin tuberculosis: based on pathophysiological criteria

I- Inoculation tuberculosis (exogenous):

– Tubering chancre

– Wartuted tuberculosis

II- Secondary tuberculosis (endogenous):

– By contiguity: Scrofuloderm

– Self-inoculation: Orificial tuberculosis

III- Blood-borne tuberculosis:

– Vulgar Lupus

– Acute military tuberculosis

– Tuberc plastic gum

IV- Eruptive tuberculosis:

– Lichen scrofulosorum

– Papulous or papulo-necrotic tubercides

– Bazin's indated erythema

– Nodular Vascularitis

I- Inoculation tuberculosis (exogenous):

1- Tubercle Chancre; mutibacillary form

2- Wartish tuberculosis: pauci bacillary form, infrequent

– tuberuloid granuloma with casey necrosis

– papillomatosis and acanthosis

– orthokeratosic hyperkeratosis

Ii. Secondary tuberculosis (endogenous):

1- The scrofuloderm: F .multibacillary

2- Orificial tuberculosis: F paucibacillary

III– Hematogenic tuberculosis:

a)– tuber lupus:

b) Acute military tuberculosis:

c) Tuberculosis gum:

Tuberculosis gums:

IV- Eruptive tuberculosis:

Skin manifestations involving immunological phenomena

1- Lichen scrofulosum

2- Tuberculides papulo necrotic

3- Bazin's indated erythema

4- knotty rash

V- skin manifestations of BCG:

On the BCG website you can have


– it is held on a bundle of arguments.

1/ Presumption elements:


– Tb screening.

– history or coexistence of visceral TB lesions.


– FNS: hyperleucocytosis with hyper lymphocytosis.

– IDR: tubercina, uses purified tubercina

– Injection of 10 IU of tubercle intradermal, on the ant side of the forearm.

– Play after 72 hours, measuring the diameter of the induration

2/ Elements of certainty:

A– bacteriological:

– this is the highlighting of the BK.

– the sample: on a skin caseous fireplace, puncture of an adenopathy, biopsy part, serouss.

1- DIRECT EXAMEN: after coloring ZIEL NELSEN, looking for BAAR

2- CULTURE on the middle of lovenstein

– For the identification of the species and the development of the antibiotic:

– the multiplication of Koch bacillus (division time – 20 hours) requiring an average growing time of 28 days, and 42 days.

B- histology:

– The characteristic but non-specific histological element of tuberculosis is the Koester follicle

C- "PCR" genetic amplification methods:

– their interest is in paucibacillary forms such as vulgar lupus, or reactionary states (erythema, indurated BAZIN), but however it lacks specificity and sensitivity,


Anti-TB chemotherapy (Rifampicin,Isoniaside,Ethambutol,Pyrazinamide)


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