Dear Abdullah, Hi & Welcome. Your son seems to be suffering from recurrent pin worm infection. For such cases I usually prescribe Albendazole for the eradication of the infection. It should be taken as a single oral dose of 200 mg at once and then another single dose of the same drug two weeks later. Since this medication does not reliably kill pin worm eggs. Therefore, the second dose is to prevent re-infection by adult worms that hatch from any eggs not killed by the first treatment. There are certain preventive measures to be followed like: 1. You must see that he washes his hands with soap and warm water after using the toilet, changing diapers, and before eating. 2. He should be given bath everyday preferably by showering, because showering avoids potentially contaminating the bath water with pin worm eggs. He should not co-bathe with others during the time of infection. 3. His fingernails should be trimmed regularly, and should avoid biting the nails and scratching around the anus. 4. Frequent changing of his underclothes and bed linens should be done every morning and these items should not be shaken and carefully placed into a washer and laundered in hot water followed by a hot dryer to kill any eggs that may be there. 5. It is also recommended that all the family members receive treatment, especially when multiple or repeated symptomatic infections occur, since such contacts commonly also are infected; re-treatment after 2 weeks may also be needed for them. Hope the advice given above would be useful in getting rid of this recurrent problem.