Answer:
You may have had an allergic reaction. Keratosis Pilaris is also a skin condition that can cause red bumps on the skin, but they usually just itch, and they don't hurt. If you have been under a lot of stress, it may be a stress rash, or maybe even a heat rash, but usually they just itch, although stress rashes usually occur in the form of hives, which can burn/tingle. If you notice anything very serious, or if the problem continues for an extended period of time/doesn't go away, you may want to contact your doctor or schedule an appointment with a dermatologist to make sure it isn't anything serious.
