itches, anywhere there is hair like privats and head , body too

[Rx_Modes]

what kind of pests could cause all three of my cats and then my son and me to get very itchy red bite marks and pretty even hair loss? no patches just a lot more hairs coming out than is typical for us both. during dryer times in winter its gets progressively better. i have found that when wiped off an extremely itch spot like my shins and around the lower leg areas like that.. when wearing socks and sandals that we have found specks which are a range from clear under black-light only to dark brown/black on paper towels. wet wipes. also pink ones and reddish ones.
washing in shower with the right shampoos has helped temporarily as we still have to be in the house with them, whatever they are.  have used de earth on cats and has helped keep them less itchy. used pyrethrin cats shampoos which had effects that weren't good over long time but was useful to clean them out of our hair etc. using 3 washes in laundry and high soap cleaned them out too. but they come back again during the day and night and if on us there are bigger and lesser times of activity..:(

Please help, i could list more details of what we have found works if need be and when it doesn't. we have had to throw away all fluffy stuff and go without coats in the winter. in the car, in the beds, on the toilets unless wiped down etc..no beds not just cots and hammocks so we could wash them better and stop sleeping in a metal chair.

is going to be summer time soon. its already more itchy than in winter time and its debilitating at times if we have to go to church or the shoppes to be in a car while itches are high and very stingily bad. plus id never want to give to others the problems we are having!

praying for a stop to these things from God but anything to id them would be helpful,
Please ask questions as there is more but its a long data stream so if you ask its helpful so nothings missing in details.<3
thanks