Efficacy and safety of multidrug therapy in paucibacillary leprosy in Singapore.

A total of 49 patients with paucibacillary leprosy (PB) who completed multidrug therapy (MDT) between 1985 and 1990 were analysed retrospectively for efficacy and complications; 20 (40.8%) patients had borderline-tuberculoid (BT), 13 (26.5%) had tuberculoid (TT), 1 (2.1%) had indeterminate (I) and 15 (30.0%) had pure neural (N) leprosy; 26 patients (76.5% of 34 non-neural leprosy) were skin biopsied for histological cure before MDT was stopped. Of these 26 patients, 19 had histological clearance at 6 months while the remaining 7 cleared beyond 1 year (18-36 months). The remaining 8 non-neural patients who refused rebiopsy had MDT for 6-8 months and the MDT was stopped when there was clinical clearance. Of the 15 neural (N) leprosy patients, 11 were given MDT for 6 months while the rest had 12-18 months of treatment; 1 patient with neural leprosy, who was treated for 6 months, relapsed with BT leprosy 18 months post-treatment. There were few complications among the 49 patients-4 (8.2%) patients developed reaction to dapsone, 1 (2.0%) had the dapsone syndrome, 2 (4.1%) had haemolytic anaemia and 1 (2.0%) had dapsone hepatitis; 7 (14.3%) patients had type I reaction.

Erythema nodosum leprosum in Singapore.

Erythema Nodosum Leprosum (ENL) or Type II reaction is an immune complex syndrome seen in multibacillary leprosy. 20 patients with histological confirmation of ENL in leprosy were studied from 1982 to 1986. These patients had a range of clinical signs, from fever, tender dusky nodules, bullae, ulcers to lymphadenopathy, arthralgia and neuritis. The four major histological patterns are: a) classical pattern showing heavy infiltrations of neutrophils in three cases, b) sub-epidermal bulla pattern with marked oedema of the upper dermis, and collections of neutrophils in five cases, c) vasculitis pattern, affecting superficial and mid-dermal vessels, leading to epidermal necrosis, bulla formation and ulceration. Dilated vessels, congestion, lumenal fibrin clots and fibrinoid necrosis of vessels were seen, d) non-specific picture in nine cases with mild oedema, infiltration with neutrophils, and two cases with minimal reaction had chronic ENL with clinical vasculitis. All the five cases with vasculitis showed C1q, C3 and fibrinogen in the vessels. Comparing ENL reactions reported in Asia, our pattern is similar to that of Malaysians with the majority showing sub-epidermal oedema. Vasculitis is more common in India. Oedema with collagen necrosis as seen in acute ENL with iritis in New Guinea. The Lucio's phenomenon was not seen in any of the countries in Asia.

Leprosy in Singapore.

The incidence of leprosy in Singapore is declining over the past 20 years. More than one third of new cases are now over 50 years while no child under 5 years has been affected since 1970. Male to female ratio is 2:1. Indians are more significantly affected compared to the other races and a higher proportion has tuberculoid leprosy. Tuberculoid leprosy accounts for 50.4% of cases seen during the past decade. Case detections from household contacts is still worthwhile as it accounts for 3% to 13.5% of the yearly incidence of the disease. The first four cases of dapsone resistance was confirmed in 1969. Since then the yearly incidence of clinically diagnosed dapsone resistant cases averaged 2.9 per thousand. Hence, various regimens of multiple drug therapy have been instituted.

Leprosy.

Leprosy is still a medical problem in the tropical and subtropical countries in Africa, Asia and South and Central America. New evidence on the airborne transmission of the disease is presented. The rest of the review deals with the clinical manifestations, the use of anti-leprosy drugs, and the treatment of reactions. Prophylaxis by BCG and chemoprophylaxis are briefly discussed.