Since time immemorial, Tuberculosis has been ranked amongst the most feared and dreaded of the numerous diseases that affect mankind. The evangelist John Bunyan1 dubbed tuberculosis as “the captain of all of these men of Death”, and in India, it was known as the ‘King of Diseases’.

In the twentieth century, incidence of tuberculosis appeared to have dropped drastically only to reappear in the fag end of the century in a more vigorous form due to infections caused by atypical saprophytic mycobacteria which were so far considered to be non pathogenic. They turned their nature in the wake of immunosuppressive disease caused by HIV infection.

Bayle2 was the first to discover that tuberculosis was not confined to lungs alone. Inspite of Villemin’s proof that tuberculosis was infectious, cutaneous tuberculosis was mistaken for other dermatosis Lupus vulgaris was known since 17th and 18th centuries. Rokitansky and Virchow described the histopathological characteristics and Friedlander showed the similarity of histologic appearance of Lupus vulgaris with tuberculosis of other organs.2 Finally, Koch’s discovery of tubercle bacillus and its confirmation of its role in the cause of tuberculosis provided the evidence.

During the study of 51 clinically suspected cases of cutaneous tuberculosis, we encountered the HIV positivity and we tried to study the common clinical morphological variant of cutaneous tuberculosis and the common mycobacterium species existing in HIV infection.

Material and Methods
ifty- one cases of clinically suspected cutaneous tuberculosis were studied over a period of 18 months. Skin biopsies and tissue exudates from the cutaneous lesions were inoculated on Lowenstein Jensen medium after preparing smears to be stained by Ziehl Neelsen’s.

The growths on the media were subjected to a battery of biochemical tests and the Mycobacterium isolates were identified to their species level.

The isolates were then subjected to anti-tuberculosis drug susceptibility using 4 drugs namely – streptomycin, isoniazid, ethambutol and rifampicin. These drugs were incorporated into LJ medium using their critical concentrations 3,4 before inspissation. The method followed was the resistance ratio method.

The serum separated from the blood collected from the patients was tested for HIV 1 and 2 antibodies by indirect micro-titre well ELISA technique. This was followed by rapid tests.

Histopathological studies were also conducted on the biopsy specimens.

The patients were started empirically on four drugs namely Streptomycin, Ethambutol, Isoniazid and Rifampicin and the resolutions of lesions were looked for upto six months.

Results

During the study it was observed that seven out of 51 (13.73%) cases of cutaneous tuberculosis had HIV infection.

All these patients had Scrofuloderma like lesions. Five patients had Scrofuloderma in the cervical region with discharging sinuses. One patient had discharging sinus in the forehead and another had disseminated tuberculosis with ulcerative and abscess like lesions with sero-purulent discharge in the abdomen.

Five out of seven isolates from HIV infected patients were M. tuberculosis. Four of these were from cervical Scrofuloderma lesions and one was from the lesion in the forehead. There were two atypical mycobacterial isolates, one of which was M. scrofulaceum from cervical adenitis and the other was M. avium complex isolated from the abdominal lesions in the disseminated tuberculosis.

Histopathology of these lesions showed features of Scrofuloderma including the ones caused by M. scrofulaceum and M. avium complex.
All seven patients however responded to the treatment with four anti-tuberculosis drugs. The resolutions of the lesions were apparent within two months of the treatment.

The anti-tuberculosis drug susceptibility also showed that all five M. tuberculosis and one M. scrofulaceum showed susceptibility to all four drugs. M. avium complex however showed resistance to all except Rifampicin. But clinically, there was resolution of lesions.

Discussion

Mycobacterial infections have been associated with HIV infections. In most cases Tuberculosis acts as presenting feature of HIV infection or AIDS related complex. Highly pathogenic organisms like Mycobacterium tuberculosis develop early whereas low-grade pathogens as Mycobacterium avium intracellulare emerge when immune deficiency is more advanced.5 HIV infected patients develop tuberculosis from reactivation of a latent tuberculosis infection as well.6 The risk of acquiring tuberculosis in patients with AIDS depends on the prevalence of the disease in the local population.7 Tuberculosis in HIV infection is more often extra-pulmonary and disseminated than in its absence.⁸

Limited literature in this regard prompted us to look into the HIV status of cutaneous tuberculosis cases included in our study.

The incidence of HIV positivity in our study was 13.73%. All Seven cases of HIV positive cutaneous tuberculosis yielded Mycobacterium isolates. The most common isolate was M. tuberculosis (five out of seven)

This conforms to the findings of Quiros et al9 in skin lesions and Dalal10 et al in extra-pulmonary cases. M. scrofulaceum and M. avium complex were the other two isolates.

M. avium complex has been reported as the most common opportunistic infection in AIDS by Collins et al11 and Lerner et al.12 Lombardo et al13 and Villas et al14 have implicated M. avium complex in AIDS in skin lesions.

The presence of HIV infection and the resultant decrease in cell-mediated immunity could lead to increased susceptibility to infections.15 It could also increase the chances of reactivation of a pre-existing tuberculous focus. The lesions would therefore become more florid with increased chances of isolating the causative organism. This could explain the high yield of organisms in our study.

All seven patients responded to aforementioned anti-tuberculosis treatment including M. scrofulaceum and M. Avium complex infection. Murray et al16 have shown clinical response to Isoniazid and Rifampicin in M. scrofulaceum infection.

Satyasri¹⁷ has mentioned in- vitro resistance with clinical response to combination anti-tuberculosis treatment especially in M. avium complex infection.
Thus in our study all seven cases of HIV infected patients yielded Mycobacterium isolates. Mycobaterium tuberculosis was the most common isolate through M. scrofulaceum and M. avium complex were also isolated.

All of them showed good clinical response conforming to invitro susceptibility. Thus in our study, cutaneous mycobacteriosis is still treatable with conventional treatment in-spite of immuno-suppression.

References

1. Grange JM. Introduction. In: Mycobacteria and Human Disease. Arnold Publishers: London, 1998 : 1–8.
2. Tappeiner G, Wolff K. Mycobacterial diseases: Tuberculosis and atypical Mycobacteria. In: Fitzpatrik TB, Eisen AZ, Wullik et al eds. Dermatology in General Medicine, McGraw Hill: New York, 1993; 2 : 2370-95.
3. Lee C, Heifets LB. Determination of Minimum Inhibitory Concentrations of anti-tuberculosis drugs by Radiometric and conventional methods. Am Rev Respir Dis 1987; 136 : 349-52.
4. Cannetti G, Fox W, Khomenko A, et al. Advances of testing Mycobacterial drug sensitivity and use of sensitivity tests in tuberculosis programme. Bull WHO 1969; 41 : 21-43.
5. Meeran K. Prevalence of HIV infection among patients with leprosy and tuberculosis in rural Zambia. BMJ 1989; 298 : 364-5.
6. Watson, Gill. HIV and TB. BMJ 1990; 300 : 63-5.
7. Goldman. AIDS and TB. BMJ 1987; 295 : 511.
8. Sunderam G, McDonald RJ, et al. Tuberculosis as a manifestation of AIDS. JAMA 1986; 256 : 362-6.
9. Quiros E, Maroto MC, Bettinardi A, et al. Diagnosis of cutaneous tuberculosis in biopsy specimen by PCR and southern blotting. J Clin Pathol 1996; 49(II): 889-91.
10. Dalal P. Tuberculosis and HIV in Mumbai. International CME on Tuberculosis. Mahatma Gandhi Institute of Medical Sciences, Wardha 1996: 30-7.
11. Collins FM. Mycobacterial disease, immunosuppression and acquired immunodeficiency syndrome. Clin Microbial Rev 1989; 2 : 360-77.
12. Lerner CW, Tapper MC. Opportunistic infection complicating immune deficiency syndrome. Medicine 1984; 63 : 155-64.
13. Lombardo PC, Weitzman I. Isolation of M. tuberculosis and M. Avium complex from the same skin lesion in AIDS. N Engl J Med 1990; 323 : 916-7.
14. Villas F, Fernandez-Capitan MC, Gomez MI, et al. Mycobacterium avium-intracellulare infection of the skin in a patient with AIDS. Ann Med Interna 1990; 7 (2) : 105-6.
15. Varghese LR. Tuberculosis and AIDS. Ind J Tuber 1991; 38 : 167-71.
16. Murray-Leisure KA, Egan N, Wietekamp MR. Skin lesions caused by M. scrofulaceum. Arch Dermatol 1987; 123 : 369-70.
17. Satyasri S. Drug resistance in tuberculosis. In: Textbook of Pulmonary and extra-pulmonary tuberculosis, 2nd Edition Interprint: New Delhi. 1995: 148.