Yes its infection
This is Dr. Davidviral infection in the abdomen can cause skin rashes and hivesthere are many different types of abdominal infections.are you having infections in your colon or stomach?omeprazole is to help decrease stomach acid levels.you should ask to see a GI doctor who can do an upper endoscopy to look down into your stomach?you should see an allergy doctor as well to check if you are allergic to any types of food. food allergies can cause chronic urticaria hives as well.
you might benefit from antihistamines to help decrease your hives. oral and cream topical skin antihistamine creams.