Summary The visually normal skin of 196 patients diagnosed clinically to have primary neuritic leprosy was studied histologically to determine whether there were any specific changes due to the disease in this site. Histological changes due to leprosy were seen in 32· 1 % of the patients, and included, indeterminate leprosy in 19-4%, borderline tuberculoid leprosy in 6·6% and borderline lepromatous leprosy in 6' 1 %. The remaining biopsies showed mild non-specific dermal inflammation, mild nerve changes or no significant lesion. The nerve inflammation and/or granulomas were mostly in the deep dermal nerves or neurovascular complexes. This study shows that there is a cutaneous component to primary neuritic leprosy and the disease is not totally confined to nerves. The absence of visible hypopigmented patches in these patients is probably related to the deep location of the dermal inflammation.

In 37 clinically-diagnosed borderline-tuberculoid (BT) leprosy patients skin biopsies were done prior to starting multidrug therapy (MDT) and at the end of 6 months therapy. Clinical and histopathological activity, graded as active, resolving and inactive, were studied at the end of 6 months of MDT. Of the 37 clinically-diagnosed BT patients 24 could be confirmed by histopathol ogy as having BT leprosy, while the other 13 biopsies showed features of indetermi nate (I) leprosy. After 6 months of MDT, out of the 24 histopathologically-confirmed BT patients, 4 (17%) showed clinical activity and 8 (33%) showed histopathological activity. Of the 13 histopathologically-diagnosed indeterminate cases all were clinically inactive but histological activity persisted in 3 cases (23%). Out of the 37 clinically diagnosed BT patients 3 showed both clinical and histopathological activity at the end of MDT.

The nasal mucosae of 39 cases of primary neuntIc 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 (5 1 %) 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.

A study was undertaken with the aim of testing the usefulness of c10fazimine as a prophylactic agent against neuritis and nerve damage. A modified regimen, using initial high doses of c10fazimine followed by regular multi bacillary multidrug therapy (MB-MDT) WHO regimen, was given to a series of consecutive cases of high risk borderline leprosy patients, fulfilling defined selection criteria (n = 65). These patients were studied for the incidence of neuritisfType I reaction, over a period of 2 years. Results were compared with a matched series of consecutive cases treated only with regular MB-MDT WHO regimen (n l = 57). The difference in incidence rates of neuritis between the two groups was significant (p < 0•01), suggesting that c10fazimine may have a useful prophylactic role against neuritisfType I reaction and nerve damage.

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