I have clusters of small red dots under the skin of one of my feet. they do not itch or hurt. i am not diabetic and have no known allergies. ?

Most likely fungal: This is what the beginning of fungal skin infection (athlete's foot) looks like. Sometimes it may look like just some dryness or scaling, and other times, small red vesicles under the skin. A dermatologist can make a definitive diagnosis by scraping the area and looking at the scrapings under the microscope.

Many possibilities: There are many things that could cause a skin rash. Several types of inflammatory conditions of the skin, allergic reactions, sun exposure, insect bites, and sometimes bacterial, viral or fungal infections can cause rashes on the skin. Have it evaluated by a professional and get the appropriate treatment.