Pinworms (Enterobius vermicularis) infect only the lower colon & don't disseminate or migrate to other areas of the body. Treatment is covered in the Mebendazole (Vermox) Protocol: http://curezone.com/forums/fm.asp?i=1564827#i. This drug is no longer available in the US but can be ordered from overseas pharmas.
Based on your symptoms of itchy rectum, scalp, & nose, your infection is likely caused by other roundworm species or tapeworms that have disseminated/migrated outside the GI tract.
Suggest you do a couple of cycles of the Albendazole Protocol for systemic roundworms: http://curezone.com/forums/fm.asp?i=1566532#i. Recommend the Valbazen suspension. Its manufacturing process & formulation provide better uptake & bioavailability than the tablets.
Post treatment, if you still have symptoms, suggest the Niclosamide, Praziquantel, & Albendazole Protocol for systemic tapeworms: http://curezone.com/forums/fm.asp?i=1602094#i. If you later decide on this protocol, let me know & I'll send you info on ordering the meds.
Topical treatments for itch relief in skin, scalp, & soft tissue:
For itchy body, recommend daily hot bath soaks with Borax, epson salts, dead sea salts, hydrogen peroxide, or apple cider vinegar added, as well as bathing with salt gel scrubs, exfoliating soaps, & sulfur soaps.
Ivermectin horse paste mixed with diaper rash cream (w/40% zinc oxide) draws out encysted parasites, eggs, & larva from sores, lesions, & rashes & heals skin & soft tissue. The horse paste can be found on EBay or local/online animal supply & feed stores.
Sulfur ointments are also effective as drawing agents & healing the skin. Check EBay, drugstores, & Walmart for these brands: Sulfur8 2% Medicated Ointment & DeLaCruz 10% Sulfur Ointment.