Q: I am 55 years old. I had a swelling on my left foot, with slight pain and itching. The doctor conducted a blood test and said that the swelling occurred due to the rise in eosinophil level. I was prescribed Hetrazan tablets. Am I on right treatment?

A:Eosinophils are a type of white blood cells (WBCs) produced in the bone marrow and contain proteins that contribute to the immunologic responses against infectious disease agents and to tissue damage in allergic and autoimmune diseases. Normally, the absolute eosinophil count in the blood is around 500 per microlitre but it can increase in: allergic conditions (asthma, allergic rhinitis, drug reactions), infectious diseases (especially worm infestation), some connective tissue diseases, malignancies, etc. The swelling in the foot was not due to eosinophilia but the other way round, i.e. whatever caused the swelling lead to a rise in eosinophils in the blood. The swelling of the foot may be due to elephantiasis, or lymphatic filariasis, a rare disorder of the lymphatic system caused by parasitic worms transmitted by mosquitoes, and that is why Hetrazan (diethylcarbamazine) has been prescribed.