An additional suspect besides the tick family is another member of the Acari - mites.
There are a number of mite species that affect humans, the most common and well known of which is the Scabies Mite (Sarcoptes scabiei). Adult females are in the range of 0.3-0.45 mm/0.012-0.018". They are spherical and you usually can't see the legs. Like all the Acari, there is little separation of the head and body, and they do not have a thorax like the Insecta. The shell of a mite is in a single piece, which will distinguish it from all the beetles, which have split wing-cases over their back.
Mite bites typically result in a red, blistering/pimple-like rash (scabies shown) that is very itchy. Scabies in particular, burrow in the skin and you can see the burrows and bites in tracks on the skin.
There are some other common types of mites that you have probably heard of if you are from Tennessee, such as the Chiggers (several species), which you (and any animals you have) can easily pick up from areas where ticks are found too. Their bite is itchy and pimple-like. Chiggers are about 0.01"/0.4 mm in size and are an orange colour. They are more oval than round, but this depends on species and life-cycle stage as well as engorgement.