I have slightly elevated redness in my arm nearest to the elbow that keeps on geeting bigger. its not that itchy but keeps on spreading ?

Dermatitis/infection: New onset of a red raised area of skin can generally be caused by an irritant, allergy or infection. An irritant (like poison ivy or chemical) can cause a contact dermatitis. An allergic reaction to something either external (environment) or internal (food/medication) can cause an allergic dermatitis. Either of these tend to itch. Infection is less likely to itch. See MD if keeps getting worse.