Sometimes when the body is very toxic and you start the healing process you can have a very bad reaction as the toxins are released as the body tries to get rid of them. The most helpful thing I found for my skin die-off rashes and dry skin was the Epsom Salts in the bath and drinking lots of water to flush out the toxins.
Another problem is if your friend is not thoroughly eliminating the toxins/ parasites through bowel movements. If they are up to it a colonic would clear the toxins out of the bowel which would stop them re-circulating back into the body or a tablespoon of Epsom Salt in a glass of water would also help this.
Fresh juices such as carrot, Celery and spinach can help to provide vital nutrients and strength.