Wr. Brieger et al., Development of reactive onchocercal skin lesions during a placebo-controlled trial with ivermectin among persons without lesions at baseline, TROP DOCT, 31(2), 2001, pp. 96-98
Clinical trials of the effects of ivermectin on onchocercal skin disease ha
ve documented reduction in itching, but a less than clear benefit on reacti
ve skin lesions. It has been suggested that one of the positive effects mig
ht be the prevention of new lesions. A study among a rural adult farming po
pulation in southwestern Nigeria provided ivermectin in three treatment gro
ups and a placebo to community members who were examined and treated at 3-m
onthly intervals over a 15-month period. Among the 1206 people recruited fo
r the study, 627 (52%) had no lesions at baseline examination. A total of 2
91 participants without baseline lesions attended all five follow-up examin
ations, and only their results were analysed. Members of all four groups de
veloped new lesions, but those receiving ivermectin had a consistently towe
r proportion of lesions than the placebo group. This difference reached sta
tistical significance at the 5% level in three of the five periods and was
below the 10% level at the other two periods. These findings are suggestive
of an inhibiting effect of ivermectin among those without lesions at the b
eginning of a community treatment programme, and justify community treatmen
t as a way of limiting morbidity and social stigma associated with these le
sions.