I have a rash on my upper outer thigh. the bumps are small and dark red when not itching yet somewhat larger and inflamed when itching. sounds like?

?herpes zoster: A patch of eruption like this may be shingles (herpes zoster)'. Another possibility is an allergic reaction to something that comes in contact with your skin. A dermatologist is best qualified to evaluate and treat you for this persistent rash.

Many possibilities: It could be any number of things. This could be a contact allergy, a reaction to something you are allergic to. It could be a cluster of bug bites. Many possibilities. You will need to be examined to determine the proper diagnosis.