What do small brown spots on the bottom of feet mean?

Many possibilities: There are many things that may cause a discoloration of the skin. Several types of inflammatory conditions of the skin, allergic reactions, and sometimes bacterial, viral or fungal infections and cancer can cause a discoloration of the skin. Insect bites can also be the cause of a rash or a discoloration of the skin. Have it evaluated by a professional and get the appropriate treatment.