Itchy bumps appear often (mostly arm/leg/back), can be goosebump-like or can get as large as bug bites. disappears in a few hours. usually not red.

Hives?: Itchy bumps that appear and disappear within hours are almost certainly hives. The cause/trigger is rarely identified, but common things to watch out for include foods, new medication or hygiene products, household/worksite chemicals. Viral infection is a frequent cause too. 25% of people have hives at some point, but usually only briefly. Can try cetirizine, but read label. If persists, get seen

Hives / urticaria : Usually, itchy bumps are urticaria, or hives. They go away in a few hours and the skin looks normal . They are white in the bump area and usually it is pink around the outside. The bumps are called wheals and the areas around them are called flares. If you don't have ANY redness anywhere, it may be eczema or something else. Antihistamines like zyrtec, Allegra or Benadryl (diphenhydramine) help the itch. See a doc!