Thought Id post a lil FYI since I hadn't seen any direct post lately.
Trombiculid mites go through a life cycle of egg, larva, nymph, and adult. The larval mites feed on the skin cells of animals. The six-legged parasitic larva feeds on a large variety of creatures, including humans, rabbits, toads, box turtles, quail, and even some insects. After crawling onto their hosts, they inject digestive enzymes into the skin that break down skin cells. They do not actually "bite" but instead form a hole in the skin called a stylostome and chew up tiny parts of the inner skin, thus causing severe irritation and swelling. The severe itching is accompanied by red, pimple-like bumps (papules) or hives and skin rash or lesions on a sun-exposed area. For humans, itching usually occurs after the larvae detach from the skin.
Because chigger wounds are a complex combination of enzymatic and the resulting mechanical damage, plus allergy and immune responses, plus possible secondary bacterial infection subject to local influences, no one remedy works equally well for most people.
It is the chiggers' digestive enzymes in the saliva that cause "the insanely itchy welts". The itching can be alleviated through use of over-the-counter topical corticosteroids and antihistamines. According to Mayo Clinic, the chiggers "fall off after a few days, leaving behind red, itchy welts" which normally heal on their own within one to two weeks. Hot showers or baths also will help reduce itching. In cases of severe dermatitis or secondary infection associated with chigger bites, a doctor should be consulted.
According to an Ohio State University Extension Fact Sheet:
...After returning from a chigger-infested area, launder the field clothes in soapy, hot water (125°F.) ....As soon as possible, take a good hot bath or shower and soap repeatedly. The chiggers may be dislodged, but you will still have the stylostomes, causing the severe itch. Scratching deep to remove stylostomes can cause secondary infections. For temporary relief of itching, apply ointments of benzocaine, hydrocortisone, calamine lotion, New Skin, After Bite, or others recommended by your pharmacist or medical doctor. Some use Vaseline, cold cream, baby oil, or fingernail polish. (The sooner the treatment, the better the results.)....