http://emedicine.medscape.com/article/229312-overview

I would start by having your child tested for allergies, celiac disease, and vitamin, mineral, and amino acid deficencies. Pin worms are very very hard to get rid of. I found that keeping vicks on the anal area at night helped to break their cycle along with pyrantel. Take for a week then take a laxitive like magnesium citrate. Do a lot of saline enemas. Wash the linens every day, wear tight underwear, vacuum often and let the sunlight in the bedroom and house. The next week take the pyrantel again and the next morning a laxitive. You want to paralyze them and get them out. they die inside you the eggs move down towards the anus. when they hit air they hatch and reinfect you. They only take 6 hours to hatch. They don't have to be outside to hatch just near the entry. They live in the tiny skin folds. Clean with alcohol the toilets after ever use. Do this for a year. You can let up on the washing of the linens once you get them contained. A clove of garlic inserted in anus keeps them from driving you insane. Garlic inside, vicks outside. Sounds crazy but it works. After you think you've got ridof them treat monthly with pyrantel and laxitive. The cuts on your arm could be strongyloides.

I read that parasites attack us when our secretory IgA is low. That is the thing that keeps our mucus membranes healthy enough to ward off parasite attacks. It also affects food allergies which I have too.

I am currently taking a serum-derived immunoglobulin but would just take some colostrum if I didn't have a dairy allergy. Also make sure you are taking a good vitamin supplement with plenty of fat soluble vitamins. And fatty acids rebuild the mucus membranes too. Matter of fact, even regular doctors recommend taking fatty acids to cure dry eyes.

The following quote is from a Gastrointestiinal Bacteriology book:
"Mucous membranes. Many are heavily colonized with bacteria in whose moist secretions they survive. These normal flora are restricted from entry and usually occupy any attachment sites that might otherwise be used by pathogens. The normal flora established on mucous membranes may antagonize non-indigenous species by other means, as well. Typically, mucus contains a number of types of anti-microbial compounds, including lysozyme and secretory antibodies (IgA). Sometimes phagocytes patrol mucosal surfaces (e.g. in the lower respiratory tract). Nonetheless, most infectious agents impinge on the skin or mucous membranes of the oral cavity, respiratory tract, GI tract or urogenital tract, and from these sites most infections occur. Damage to the epithelial cells caused by toxic products of these bacteria may play a role. "

So you have to focus on boosting your immune system. Sounds easier than it is. I just started the immunglobulins so can't say they are working yet.