Cutaneous tuberculosis (overview) A18.4

A classical infectious disease occurring worldwide, which must be reported by name and most frequently affects the lungs, intrathoracic lymph nodes, bronchi and pleura. Tuberculosis of the urogenital tract, peripheral lymph nodes, bones, joints and skin is not uncommon.

Pathogen: Mycobacterium tuberculosis complex.

The following species belong to this group:

• (M.) tuberculosis (99%; man as reservoir)
• M. bovis (bovine tuberculosis)
• M. africanum (humans as reservoir, see mycobacteria).

The disease can start highly acute, acute, subacute, chronic and also asymptomatic. Untreated relapsing course.

A distinction is made between:

• primary cutaneous tuberculosis
• post-primary tuberculosis.

Primary cutaneous tuberculosis: the primary tuberculous complex of the skin as an exogenous primary infection through direct contact of an injured skin site with tuberculous material and the formation of a nodular infiltrate with caseation and ulceration as well as regional lymphadenitis is rare.

Postprimary tuberculosis: postprimary cutaneous tuberculosis may develop by inoculation or by endogenous spread.

Depending on the immune status, the following clinical pictures develop (see table):

• Tuberculosis cutis luposa
• Tuberculosis cutis colliquativa
• Tuberculosis cutis verrucosa
• Tuberculosis fungosa serpiginosa
• Tuberculosis cutis miliaris disseminata
• Tuberculosis subcutanea et fistulosa.

Primary tuberculous complex of the skin as an exogenous primary infection due to direct contact of an injured skin site with tuberculous material and the formation of a nodular infiltrate with caseation and ulceration as well as regional lymphadenitis is rare.

An estimated 1/3 of humanity is infected with tuberculosis pathogens. About 15% of those infected develop relevant active tuberculosis. About 95% of the cases and deaths concern the developing countries. Apart from the general state of nutrition, the high HIV-infection is responsible for this.

The average incidence in Germany is 5.4/100,000 inhabitants/year. It is higher in various risk groups (HIV-infected persons). It is significantly higher among various risk groups (HIV-infected persons, immunosuppressed persons, drug addicts, malnourished persons, migrants from high-risk countries).

TB is the most frequent cause of death among AIDS patients. Multidrug-resistant tuberculosis (MDR = resistance to at least INH+RMP) is becoming an increasing problem (the number of infected people is estimated at 50 million worldwide). Countries with high burden of MDR tuberculosis are (according to WHO, as of 2013: Ethiopia, Armenia, Azerbaijan, Bangladesh, Bulgaria, China, Congo, Estonia, Georgia, India, Indonesein, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Myanmar, Nigeria, Pakistan, Philippines, Russia, South Africa, Tajikistan, Ukraine, Uzbekistan, Vietnam, Belarus).

Cutaneous tuberculosis affects approximately 1.0-1.5% of all extra-pulmonary tuberculosis infections.

Transmission most often by droplet infection, rarely by skin contact with infected material or through food.

Microscopic(Ziehl-Neelsen staining) or cultural pathogen detection (only culture and animal experiments are reliable - see below mycobacteria).

The Quantiferon-TB-Gold-Test has established itself as the serological detection method. This is a highly sensitive immunological test for tuberculosis screening, in which the tuberculosis-specific antigens ESAT-6 (early secretory antigen target-6), CFP-10 (culture filtrate protein 10) and TB 7.7(p4) are used. These only occur in M. tuberculosis and M. bovis.

Skin tuberculosis

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2. Koch R (1884) The aetiology of tuberculosis. Mittheilungen aus dem Kaiserlichen Gesundsheitsamte 2: 1-88.
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6. Senol M et al (2003) A case of lupus vulgaris with unusual location. J Dermatol 30: 566-569.
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9. current treatment regimens. Tuberculosis (Edinb) 95:629-638