Itchy rash on stomach and chest for 3-4 days now... 2% hydrocortisone isn't working and rash is slightly raised and red?

Rash: Hard to say without a photo. It can be a reaction to something external, that is an allergy or a manifestation of an internal process. Some rashes may be associated with viruses and other infections. It would be best to have your doctor take a look.

Rash: Your rash may be pityriasis rosea which is a red itcht rash. It does not respond to hydrocortisone because the rash is caused by a fungus that lasts for 6-8 weeks. Using blue selsun hair shampoo may be helpful. Of course, a visit to a dermatologist would also help to confirm the diagnosis