Pathogenesis of dry eye in leprosy and tear functions.

Seventy-five leprosy patients and an equal number of age- and sex-matched controls were examined for tear functions, using Schirmer's test and tear break up time (BUT). There was no statistically significant difference in the Schirmer's test, but the tear BUT showed a statistically significant lower value of < 10 seconds in multibacillary patients compared to paucibacillary patients. Leprosy patients with lagophthalmos and decreased corneal sensation showed a lower value of tear BUT which was also statistically significant. This study shows that even though the quantity of tears is not affected, proper and prolonged wetting of the cornea is deficient in many leprosy patients.

Histological changes in the nerve, skin and nasal mucosa of patients with primary neuritic leprosy.

Primary neuritic leprosy (PNL) presents as a peripheral neuropathy with no visible skin patches and skin smears negative for acid fast bacilli. The pathogenesis of PNL is poorly understood. The aim of the study was to document the histological changes in the nerve, apparently normal skin and nasal mucosa in PNL and to study its significance to the pathogenesis of leprosy lesions. The study is based on a cohort of 208 PNL patients registered at the Schieffelin Leprosy Research and Training Centre, Karigiri. All patients had a nerve biopsy, 196 had a skin biopsy and 39 had a nasal mucosal biopsy. The findings reveal that PNL patients exhibit a spectrum of disease histologically in the nerve ranging from lepromatous to tuberculoid leprosy with a significant proportion (46%) manifesting a multibacillary leprosy histology. Findings in the apparently normal skin and nasal mucosa reveal that there are widespread changes due to leprosy in tissues such as the skin and nasal mucosa even when the disease appears clinically confined to a few nerves. PNL may be an early stage in the pathogenesis of the disease before the appearance of skin lesions. The number of nerves enlarged and lepromin status did not give any clue to the nature of underlying disease.

Hypopigmented face patches; their distribution and relevance to ocular complications in leprosy.

Eighty-two leprosy patients with hypopigmented patches over the face (cases) and an equal number of age-, sex-, and classification-matched leprosy patients without any hypopigmented patches over the face (controls) were examined for the distribution of hypopigmented facial patches, areas of anesthesia over the face, and eye complications. The hypopigmented patches did not follow any pattern and overlapped in the areas of sensation supplied by the three branches of the trigeminal nerve. Anesthesia over the face, evaluated by a Semmes-Weinstein monofilament which exerted a force of 0.05 grams, was present in 19.5% of the cases and 15.9% of the controls. Patients with hypopigmented facial patches were found to have more corneal hypoesthesia than patients who did not have hypopigmented facial patches. The risk of having impaired corneal sensation was three to four times higher in patients with hypopigmented facial patches. This feature can be used to identify decreased corneal sensation among leprosy patients under field conditions where direct estimation of corneal sensation is not advocated.

Epidemiological significance of first skin lesion in leprosy.

The epidemiological significance of monolesions in leprosy and the possible inferences on the mode of entry by Mycobacterium leprae into the body are presented based on data from the clinical records of the Leprosy Control Programme of Gudiyatham Taluk in India; 660 children with monolesions (335 males, 305 females) younger than 15 years of age and detected during the period 1990-1995 were included in the study. Detailed investigations on the location of monolesions were carried out and compared with a random sample of 669 normal rural children matched for age and sex. A large majority of the leprosy monolesions were in the uncovered parts of the body, with special predilection for the posterior aspects of the upper extremities and the anterior aspects of the lower extremities. Based on observation of normal children, these happen to be precisely the sites vulnerable for trauma since they are exposed to the environment where M. Leprae could enter through abraded skin and manifest as a patch. The need for further studies is emphasized.

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.

Histological studies in primary neuritic leprosy: changes in the apparently normal skin.

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.

Incidence of nerve damage in leprosy patients treated with MDT.

The incidence rates of sensory and motor impairments during and after multidrug therapy (MDT) are reported for a prospective cohort of patients who had no nerve damage at registration (N = 1621). Sensory and motor loss increased with age and both were high among multibacillary patients as compared with paucibacillary patients. The lateral popliteal (common peroneal) and posterior tibial nerves seem to be most affected for sensory loss; whereas the posterior tibial and ulnar nerves are mainly responsible for motor loss. No significant difference by gender was found. Implications for prevention of disability (POD) activities are discussed and suitable recommendations made.

Profile of leprosy in children: past and present.

The profile of leprosy in children currently seen in a referral hospital is compared with that of children with leprosy admitted in the 1970s. Children with leprosy under the age of 15 years in 1974 and 1979 comprised one group (Group I) while those during 1989 and 1994 constituted the second group (Group II) The variables studied included age, sex, type of leprosy, deformity and contact status. Multidrug therapy (MDT) was introduced in the treatment of leprosy in 1982. The probable change it has made in the presentation of leprosy in children is discussed.