For About Three Weeks I Have Been Noticing Large Red

For about three weeks I have been Noticing large red welts that at first I thought we're mosquito bites. They appear in clumps of 1 to 4, about the circumference of a dime. They first appeared on my butt ox then my hips and waist line, especially where the bands of my underwear would rest. I had a few around my bra line. They itch for a few days and then begin to dry up and scab over.