What Causes Crawling Sensation On The Hand?

MY HUSBAND HAD A EAR OPERATION APPROX. 3 MONTHS AGO AND ON BEING DISCHARGED FROM HOSPITAL ON THE BACK OF HIS HAND WHERE THE CANULA WAS INSERTED HE HAS HAD A WORM LIKE PARASITE UNDER THE SKIN THAT IS TRAVELLING ACROSS HIS HAND AND ALTHOUGH VISITING HIS GP SEVERAL TIMES IS NO NEARER TO HAVING A CURE HE IS TAKING SEBREN CAPSULES BUT THEY SEEM TO BE DOING NOTHING ANY IDEAS?