Hi Itching over anal region could be due intestinal parasites,diarrhoea, candidiasis or anal fissures etc. You must be diagnosed before taking any specific treatment. For that,you must be checked by surgeon for complete history and thoroughly clinical examination. You may require routine blood count, stool examination for R/M ova and cyst and proctoscopy etc. Treatment is mainly depend on the underlying cause but you may require full course of antibiotics (quinolones-ofloxacin with antiprotozoals like metronidazole/tinidazole/ornidazole) for minimum 7 to 10 days with antihelminthic, antihistamines and topical steroids and lignocaine in combination for symptomatic relief. Thanks.