Background: Lymphadenitis is one of the clinical signs of toxoplasmosis. Co-Trimoxazole (CTM) has a good therapeutic effect on ocular and cerebral infection of T.gondii. Since this infection is epidemic in Ahvaz and due to lack of study of therapeutic effect of CTM on Toxoplasmosis Lymphadenitis (TLA), this study was carried out to determine the therapeutic effects of CTM on TLA in Ahvaz from 2005-2007.

Methods and Methods: Forty six patients with TLA were enrolled in this controlled clinical trial study. Diagnosis was based on clinical examination, serological tests (chemiluminisent) and histo-pathological examinations. Palpable lymph node, IgM>8 IU and follicular hyperplasia were defined as positive findings. The patients were randomly divided into 2 groups of 23.The test group was treated by CTM (48 mg/kg/day divided in 2 dosages) for 1 month. The control group was only observed for 1 month. The patients were followed up by physical and serological examination in month 1, 3 and 6. No palpable lymph node and IgM<6 IU were found as clinical and serological response. The data were analyzed in SPSS software using x² test.

Results: At the end of treatment, clinical response was observed in 15 patients (65.2%) from the test group and 5 (21.7%) patients from the control group. Serological response in the test group and the control group were 52.2% and 13% respectively. There was a significant difference in therapeutic effect between two groups (p<0.05).There was no difference concerning age, sex and site of infection between the two groups (p>0.05).

Conclusion: CTM displays a good therapeutic effect on TLA and may be used in the selected patients who need treatment.