Cervical lymphenditis. It with medicine.

There were tonsillitis on left side of neck.there are multiple enlarged lymph nodes on maximum of 2.7 Cm on left side of neck in sub mandibular region. The infection of tonsillitis has been subsided most of the extent by regular intake of antibiotics however the lymph nodes are not subsiding.These are existing since last 20 days. As per CBC report lymphocytes level is 50.Absolute lymphocytes count is 3950 Cells/cu mm. As per ESR it is 38 MM at the end of one hour. As per Mantoux report the same is negative. As per FNAC report The geimsa stain smears from left cerrvical swelling are inadequate for opinion. 4 air dried smears recived for opinion and smears are homodiluted  and reveals only occasional lyphoid cells.No other representative cellular element seen in smears.No epitholiod cells/granuloma/parasite/malignant cell see in the smears studied. What exactly cause and how to cure it with medicine.