Incidence of cutaneous tuberculosis in patients with organ tuberculosis

Tuberculosis continues to be a health problem in some countries. The development of resistance to antituberculitic drugs and the increase in diseases and conditions associated with immunodeficiency such as AIDS and chemotherapy have caused tuberculosis to increase recently. As a result, the incidence of cutaneous tuberculosis has been increasing as well.

To detect cutaneous tuberculosis in patients with organ tuberculosis and to establish some characteristics of the relation between organ and cutaneous TB.

A total of 370 patients (145 females and 225 males), aged 2-76 years (mean age 27.5), enrolled for this screening study. These patients were hospitalized patients who already had pulmonary or extrapulmonary tuberculosis diagnosed before admission. All patients underwent a general skin examination, and, if needed, cutaneous biopsies were taken from involved skin areas.

Three hundred and forty-seven (93.78%) out of 370 patients had pulmonary tuberculosis only or in association with one of other organ tuberculoses. Twenty-three patients had extrapulmonary TB: nine were TB adenitis, six were TB peritonitis, three were bone tuberculosis, and five were TB meningitides. Of 370 patients, only 13 (3.51%) had cutaneous TB: seven scrofuloderma (SCD; 2.16%), four lupus vulgaris (LV; 1.35%), one LV and SCD, and one Bacille Calmette-Guerin (BCG) adenitis (0.027%). Cutaneous tuberculosis was observed in seven out of 260 patients with parenchymal tuberculosis (2.96%). Four out of nine patients with TB adenitis (44.4%), one out of 12 pulmopleuretic (8.3%), and one out of 67 pleuresic patients (1.40%) had cutaneous TB as well. Mean age of the 13 patients was 32.46 years: mean age of SCD and LV was 24.8 and 48 years, respectively. The one patient with BCG adenitis was 7 months old. Five (62.5%) out of eight patients with SCD, and only one (20%) out of five patients with LV were new cases. Four patients with SCD had a positive family history, while LV patients did not.

Organ tuberculosis is rarely associated with cutaneous tuberculosis. Scrofuloderma and LV are the most frequent forms of skin TB associated with organ TB in this population. Tuberculosis adenitis is the organ TB that causes cutaneous TB most often among other organ tuberculoses. More than one form of cutaneous TB affected only one patient with pulmonary TB; therefore, it is very rare. Tuberculids were not observed in any of the patients.