Cutaneous tuberculosis

Robert Koch 1882 (Tuberculosis in general)

Skin tuberculosis, scruphuloderm, lupus vulgaris, Koch's disease

Group of skin conditions that are defined as reaction to tuberculosis-derived antigens and/or direct pathology induced by tuberculosis bacteria. 

Rare in industrialized countries, however in poorer countries, up to 30% of all persons have latent tuberculosis and of these, every fifth develops active disease. 

M. tuberculosis accounts for >99% of all cases, M. bovis and M. africanum for the rest. Atypical mycobacteriosis such as in immunosuppression are counted separately. 

Skin tuberculosis in anergy:

Anergy means the intradermal tuberculin test is negative. The lack of cellular defence against M. tuberculosis can be caused by several circumstances. A lack of contact with M. tuberculosis as well as a weakened immune defence can be decisive for the negative tuberculin test.

• Tuberculous primary complex.
• Tuberculosis cutis miliaris disseminata.
• Tuberculosis (miliaris) ulcerosa mucosae et cutis.
• Tuberculosis fungosa serpiginosa.

Skin tuberculosis in normergy:

There is a tuberculosis-specific immune reactivity. These are postprimary forms of tuberculosis (patients have already had a primary tuberous complex). Typicall few pathogens, tuberculous granulomas and a positive tuberculin test.

• Tuberculosis cutis verrucosa.
• Lupus vulgaris.
• Tuberculosis cutis colliquativa.
• Tuberculosis subcutanea et fistulosa.

Skin tuberculosis in hyperergy: 

If the tuberculin reaction is exceptionally intense, it is called hyperergy. In most cases, the tuberculin reactions do not have to be particularly high.

• Lichen scrophulosorum.
• Papulonecrotic tuberculid.
• Erythema induratum Bazin.

See the various conditions. Very broad differential diagnosis. 

• Clinical features
• Biopsy
• Detection of bacterial DNA by PCR
• IFN-gamma release assay detects an adaptive immune reactivity to tuberculosis

Can occur anywhere, head and neck region most common. 

Very good when treatment is initiated, except for irreversible residual pathology such as scarring. 

1. Sehgal, V.N., et al., CUTANEOUS TUBERCULOSIS: THE EVOLVING SCENARIO. International Journal of Dermatology, 1994. 33(2): p. 97-105.
2. Macgregor, R., Cutaneous tuberculosis. Clinics in Dermatology, 1995. 13(3): p. 245-255.
3. Stenger, S. and R.L. Modlin, T cell mediated immunity to Mycobacterium tuberculosis. Current Opinion in Microbiology, 1999. 2(1): p. 89-93.
4. Sehgal, V.N., et al., Tuberculosis verrucosa cutis (TBVC). Journal of the European Academy of Dermatology and Venereology, 2000. 14(4): p. 319-321.
5. Barbagallo, J., et al., Cutaneous Tuberculosis. American Journal of Clinical Dermatology, 2002. 3(5): p. 319-328.