Treatment of eosinophilia with albendazole.

Twenty-five patients with eosinophil counts > 1,000/mm3 of unknown etiology were treated with albendazole 400 mg twice daily for 7 days were compared with 25 eosinophilic control patients who were not treated. The average eosinophil count in the treated group was 2,079/mm3 (range 1,002-7,629/mm3) and in the control group was 2,047/mm3 (range 1,002-6,468/mm3). One month later the eosinophil counts of both groups were re-evaluated. Effective treatment was defined as an eosinophil count < 1,000/mm3. In the treatment group, 80% had a reduction in the eosinophil count to < 1,000/mm3 while only 12% of the control had a reduction to this level. No side effects were observed in either group. In conclusion, albendazole was found to be highly-effective in the management of patients with eosinophilia without obvious causes.