Sorry to hear about your friend......I had a similar problem when my neighbors chickens
infested my home with mites.....I also live on the edge of a canal.....with scrub mangroves......a place where chiggers and other types of mites are usually found
Chiggers rat mites or bird mites (ground feeding birds) have a higher rate.....can carry scrub typhus Ricketts....liquid band aid or clear nail polish will heal the bites by means of suffication....mineral oil vasoline will sufficate them and hand
sanitizer (mostly alchol) will make them release....then give a good soapy scrub
I have long blonde hair....I had to use hair dye to get them out of my hair,,,,UG
Chiggers and Cheynella mites do not live under skin ....they feed on the Kertin (top layer) and can leave itchy or blister like leasions.....adult chiggers do not bite only the larval stage feed then fall off usually at a sockline waistline or collor of sleaves of clothing....mites like seams of clothesl....if the seams of your clothes itch.....thats a good indication your clothing are affected ....ironing or steaming is the old fashioned remody.....socks microwave well and shoes can be treated with pyrethrium......so can clothes and bedding see camping hiking or an outfitters store they have spray for ticks and mites.....I just buy Safer brand cysamthium flower pyrethrium at the hardware store and mix it then I spray and let the treated clothes I am going to work in the house in sundry.......I also clean and spray my laundry area thouroly before and after doing questionable laundry......
Home Products didnt work for me bombing every three days is Overwhealming and time consuming.....I treat my truck seats and carpet with the same and let it dry and air overnight works like a charm......I called Do It Yourself Pest Control they have online chat also......Conquer 16oz makes 240 gallons.....was recommended....Nylar
added to the mix stops reproduction....I did call to have the house tented but mites are like ticks tenting they said only kills the adults not the eggs ....they also make bombs with nylar that they say will work for 7 months.....when I figure out a sure fire way to get rid of these Ill let you know right now its like trial and error