Suggest Treatment For Itchy Raised Bumps On The Back And Feet

mostly at night, i develop small raised lumps that ich intensly, on my back, shins and top of feet, my top arms, back of hands. when i scratch them the area might redden or flush , or just raise a bit more. i do have allergies to grass and the like, dust and mold. we can not relate this flies, flees or other bugs in most cases. back of arms gets red/maroon spots that cluster together and form larger redish areas and brouse looking area that takes a few days to lessen and go away. i ve been on antibiotics the past 3 weeks for sinus, chest and - suspected- jaw/gum infection. i have sensative skin and awareness characteristics all my life. any ideas? ted