These itchy bumps that appear when you scratch your arms could be hives. Hives are raised, often itchy, red welts on the surface of the skin. They are usually an allergic reaction to food or medicine.
When you have an allergic reaction to a substance, histamine and other chemicals are released into your bloodstream, causing itching, swelling, and other symptoms. Some of the trigger factors for hives are medications, foods like shellfish, fish, nuts, eggs, milk, and other foods, pollen, animal dander (especially cats), insect bites.
The welts tend to start suddenly and resolve quickly. When you press the center of a red welt, it blanches (turns white).
They can also change shape, disappear, and reappear within minutes or hours. The treatment is oral anti-histamines like Cetrizine/Loratidine. You may also apply Calamine lotion or menthol based creams on the itchy areas to soothe the irritated skin.
Hives may be uncomfortable, but they generally are harmless and disappear on their own. In most cases, the exact cause of hives cannot be identified.
First off, thanks for the advice. Will taking Zyrtec help? I used to take it for seasonal allergies.