The use of ivermectin for scabies.

BACKGROUND. Ivermectin, a modified avermectin, is widely known to be an ectoparasiticidal agent in animals but its effect on human ectoparasites is not known. METHODS. As a part of a chemotherapy trial with ivermectin against Wuchereria bancrofti microfilaraemia, two males with clinical scabies were studied. Three skin scrapings were taken from the lesions of each of the cases and examined with potassium hydroxide solution for the presence of eggs, larvae or adult mites. RESULTS. Following a single oral dose of ivermectin at either 100 micrograms or 20 micrograms/kg body weight both the itching and eruptions were reduced and the lesions healed after 14 days of treatment. Skin scrapings taken on days 7 and 30 after administering the drug did not reveal any mites. However, the lesions reappeared after 3 months. CONCLUSION. The beneficial results on the healing of scabetic lesions following ivermectin therapy indicates that the drug may have a scabicidal effect. Reappearance of the lesions may have been due to an inadequate dose. This emphasizes the need for future controlled trials on the efficacy of ivermectin against human scabies infection. If proven, this may be an additional advantage in mass chemotherapy campaigns, when there is co-existence of filariasis, intestinal helminthiasis and scabies.

Ivermectin in the treatment of bancroftian filarial infection in Orissa, India.

Ivermectin treatment was evaluated for its efficacy and side reactions in sixty patients of Orissa with Bancroftian filarial infection and microfilaremia. Ivermectin was administered as a single oral dose at four dosage levels (20, 50, 100 and 200 micrograms/kg), and both microfilarial clearance and associated side reactions were monitored in a double blind fashion. Blood microfilariae were cleared in all patients at all dosages within 1 to 14 days. In most patients microfilariae reappeared by third month. The microfilaria appearance by third and sixth month averaged 12.2 to 44 percent of pretreatment values in the four study groups. Side reactions were encountered in almost all patients, the commonest being fever, headache, weakness, myalgia and cough which occurred most prominently 12 to 72 hours after treatment. Side reactions were more frequent and severe in patients with high microfilaria counts. Clinical reaction scores for each group were independent of the dose administered. The 200 micrograms dose group showed significantly more rapid microfilariae clearance and its delayed reappearance as compared with the other dosage groups and without inducing significantly greater clinical reaction scores.

Tropical pulmonary eosinophilia in an Orissa village.

BACKGROUND. Tropical pulmonary eosinophilia is usually seen in areas endemic for filariasis. It affects only a small proportion of the population at risk and microfilaria are rarely demonstrated in the peripheral blood. The actual prevalence of the tropical pulmonary eosinophilia syndrome has not been previously studied in an area endemic for filariasis. METHODS. We screened the population of a village in the Puri district of Orissa, where filarial infection is endemic, to determine the prevalence of tropical pulmonary eosinophilia by clinical examination measuring the absolute eosinophil counts, performing a chest X-ray and examining the stools for the presence of the parasite. Sera from symptomatic cases who had an eosinophil count above 2000 per cmm were further tested for filarial specific IgG and total IgE and the results compared with control sera obtained from 15 age- and sex-matched normal individuals. RESULTS. We were able to screen 1754 (91%) out of 1918 villagers who were more than 5 years old and found 69 cases who had typical clinical features of tropical pulmonary eosinophilia. Only 6 (0.34%) of these had eosinophil counts above 3000 per cmm and were considered to have the disease. Only 2 of the 6 had associated filarial lesions, one had microfilaraemia and 3 had typical chest X-ray changes. The mean (+/- SD) titres for filaria specific IgG (0.355 +/- 0.315 v. 0.120 +/- 0.092) and total IgE (0.455 +/- 0.316 v. 0.114 +/- 0.075) were significantly higher in cases with tropical pulmonary eosinophilia than in control subjects. The level of eosinophilia was related neither to the patients' immune status nor to the severity of the radiological lesions. All cases recovered after therapy with diethylcarbamazine. CONCLUSION. Tropical pulmonary eosinophilia is not uncommon in this community in Orissa where filariasis is endemic. However, the syndrome is rarely associated with clinical filarial lesions.