My Son Has Red Circle Bite About The Size Of A Dime With A Small Blister In Center About The Size Of A Grain Of Rice. He Got It At Night While Sleeping In Bed. What Could It Be?

The insects like spiders and  mosquitoes sit on dead decaying material and carry toxin with them. These when bit to human can cause infection like your son is having. Apply topical antibiotic on the bite site not cortisone because the cortisone can not be applied on wounds/cuts and infection. Also give him anti inflammatory and anti allergy syrups. But it will be better to visit to doctor for prescription.