if you have been bitten by chiggers, try to not scratch the affected regions. Scratching could scrape off chigger larvae, but it may also cause increased irritation by breaking the skin and leaving it vulnerable to a more serious infection. The most effective way of removing chiggers is by taking a hot shower and washing the affected areas with mildly hot water and soap, as soon as possible after exposure or possible exposure (an Epsom salt bath may help alleviate pruritus. Once symptoms appear, it may be too late to prevent further bites. Taking a hot bath when already covered with chigger bites may in fact be very uncomfortable and increase itching symptoms. Do not rub and scratch the skin aggressively, but instead gently but firmly rub the irritated skin with warm soapy water. A covering to reduce air exposure over the itchy area, such as calamine lotion, petroleum jelly, or baby oil, may help relieve the pain, but they do not cure the bites. The application of a small drop of finger nail polish (usually clear nail polish) is one of the most popular remedies and is claimed to reduce itching and dry the itchy sores in the least number of days. It seems that pimple cream containing Benzoyl peroxide will kill the mite larva overnight, and if applied quickly enough, can prevent most of the symptoms. Rubbing alcohol is not recommended and it is very painful and no more effective than other measures.
Chiggers seem to affect warm covered areas of the body more than drier areas. Thus the sock covered ankles, shoe covered feet, behind the knees, and crotch areas should be carefully cleaned. Special attention should be given to small children, as areas higher in the body (chest, back, waist-band, and under-arms) may be affected more easily than in adults, since children are shorter and may more likely than adults come in contact with low-lying vegetation and dry grass where chiggers thrive.
Clothing, especially the pants and socks should be immediately discarded after returning from areas where exposure may have occurred, especially with children. The person should immediately shower washing carefully the ankles, feet, and behind the knees and under the arms and chest in children especially.
To avoid being afflicted by chiggers, always wear tight weave, protective clothing and long pants. Spray insect repellent on your skin for further protection. Application of repellent to the shoes and lower pants is helpful. Staying on trails, roads, or paths can help prevent you from meeting chiggers, ticks, spiders, snakes, and other nuisances and dangers.
Dusting sulfur is used commercially for mite control and can be used to control chiggers in yards. The dusting of shoes, socks and pants legs with sulfur can be highly effective in repelling chiggers.
People who pick wild blueberries in the summer have traditionally been very vulnerable to chigger bites. These people used to apply deodorant soap and let dry on the skin without rinsing of the arms and legs to help prevent bites.
Check this link