Nasal mucosa and skin of smear-positive leprosy patients after 24 months of fixed duration MDT: histopathological and microbiological study.

The skin and nasal mucosa of 10 lepromatous leprosy patients who had completed 24 doses of fixed duration multidrug therapy (MDT) but who continued to be skin-smear positive for acid-fast bacilli (AFB) were examined histopathologically. The nasal mucosa showed granuloma fractions that exceeded those seen in the skin specimens, signifying that activity in this region subsides much more gradually than the activity in the skin. Mouse foot pad studies done using T900r mice with an inoculum from the nasal mucosa biopsy specimens of these patients did not demonstrate any growth of Mycobacterium leprae, indicating that these bacilli were not viable. A skin specimen from one patient grew significant amounts of bacteria in the T900r mouse foot pad. These results show that 2 years of treatment with MDT would prevent dissemination of M. leprae from the nasal mucosa and, therefore, should preclude further transmission of the disease. It also indicates that viable bacteria might persist in the skin of patients, especially those with an initial bacterial index of > or = 4+ who have completed 24 doses of regular MDT. Therefore, a more cautious approach to administering only 12 doses of MDT to highly positive multibacillary patients is suggested.

Histological studies in primary neuritic leprosy: changes in the nasal mucosa.

The nasal mucosae of 39 cases of primary neuritic leprosy (PNL) registered at Karigiri were studied histologically to determine nasal mucosal involvement in PNL and its relevance to the pathogenesis of the disease. Specific changes of leprosy were seen in 20 (51%) biopsies, ranging from macrophage granulomas with acid fast bacilli, to epithelioid granulomas and nerve inflammation. The remaining biopsies revealed chronic inflammatory changes of the mucosa or mild non-specific nerve changes. These findings show that there are widespread effects of the disease even in PNL patients in whom the disease is believed to be confined to the peripheral nerves. The findings also show that early leprosy involvement can be found in the nasal mucosa even before lesions become apparent in the skin or other parts of the body. The nasal mucosa could be one of the sites for the primary lesion in leprosy. Clinical and histological examination of the nasal mucosa may be useful and important in the early diagnosis of leprosy and especially in contacts.

Light and electron microscopic findings in rhinosporidiosis after dapsone therapy.

Morphological findings in serial nasal mucosal biopsies from three cases of rhinosporidiosis on dapsone therapy were compared with biopsies from 33 patients taken before dapsone or surgical treatment was initiated. All biopsies were examined by light microscopy and five by electron microscopy. Counts of histologically intact and degenerated organisms showed a decreasing proportion of intact forms with treatment.

Reactional states in the nasal mucosa: a clinical and histopathological study.

Twenty leprosy patients in the reactive phase of the disease were studied clinically and histologically for evidence of reactive lesions in the nasal mucosa. Ten of 14 patients with erythema nodosum leprosum (ENL) showed characteristic polymorphonuclear leukocytic infiltration and two patients showed vasculitis. The histological changes of reversal reactions in the nasal mucosa, one with upgrading reaction and the other with downgrading reaction, are reported.