Further Work on Pyrethrum in the Treatment of Pediculosis

pyrethrum (Roy, Ghosh and Chopra, 1941). The important point which came to light may be recapitulated. Pyrethrum prepared in the form of an extract by heating the powder in water or mixed with white vaseline proves fatal to lice, but fails to act on nits. This necessitates the continuation of the treatment during the whole period extending over the incubation period of eggs. Observations made in Calcutta by the wrislet method indicate that the duration of the egg stage varies from 5 to 8 days in summer and from 7 to 10 days in winter. It will thus be seen that though pyrethrum used in the forms stated above efficiently acts on adults yet suffers from the disadvantage that it does not act on nits on account of the fact that it cannot penetrate either the egg-shell or passthrough the operculum. We now present a report on the remarkable efficacy of a mixture of kerosene and pyrethrum, or deobase oil and pyrethrum in the treatment of infestation with louse. It has certain definite advantages over other forms of treatment in that only one application is necessary and according to our experience eggs and adults arc always destroyed. As a rule louse infestation among hospital patients is not so common in this country, possibly owing to the free use of oil and practice of taking daily baths. However, a large number of the female patients, all evacuees from Burma, who were admitted into the hospital for treatment of other diseases, had lice in their hair and the infestation was as a rule heavy. This opportunity was made use of to test the usefulness of pyrethrum in louse infestation of the hair. Before the actual tests were undertaken