red itchy welts on face/chest

I started with a small red, non-itchy rash on my left cheek, that soon spread to my other cheek. Soon after, I noticed tiny red bumps that itch on my forearms. The next day, I noticed a few red bumps on my chest, which quickly became large, red, horribly itchy welts. This was all last Sunday-Monday, and now it's Friday.

I ended up going to the ER to get a shot of dexamethasone, which should have helped with the itching within 3-4 hours, but no luck. The next day, Thursday, I went to my GP, where I got another shot, a script for Prednisone, and orders to take Benedryl. Still today, Friday, I'm as itchy as ever. The parks on my face and chest are hot, red and itchy, with only ice packs helping. My GP gave me a script for amoxicillin, which I just started taking.

I really have no idea what's going on, as my GP is not that great at explaining. Any ideas as to what might be going on?

[Dr_Aparna]

Hi,
Itchy welts are usually hives. Hives are red, itchy welts or swellings on the skin that often come in clusters.

Hives can appear anywhere on the body, cropping up either in one small area or covering large patches of skin. They most often occur as part of an allergic reaction. No one lesion lasts more than 24 hours, but new ones may continue to appear until the condition resolves.

Hives usually appear suddenly and go away on their own in a matter of days, hours, or even minutes. Chronic hives, however, can last for six weeks or more.

Hives are often caused by a hypersensitivity to:
•Foods (commonly eggs, shellfish, nuts, berries, dyes, or other additives)
•Drugs (any drug can touch off an allergic reaction, although allergies to penicillin, sulfa, and aspirin are especially common)
•Pollens and plants (nettles, poison ivy, poison oak, and so on)
•Animal fur
•Insect bites or stings
•Exposure to heat, cold, or sunshine.
Other potential triggers include physical exertion or exercise, stress, illness, chemicals, cosmetics, textiles, and pressure from materials rubbing against the skin.

To soothe itchy skin, try cold compresses, calamine lotion, a cool shower, or a tepid bath with a few tablespoons of cornstarch .
The rate of recovery really depends on what has triggered off the outbreak, in your case it seems to be a violent response. So it will take time to settle down.

Do not scratch the welts as that will increase the itching. Continue to take the steroid medications and anti-histamines like Cetrizine, thogh it causes drowsiness it wil be effective in treating the rash.

ref:http://www.myonlinewellness.com/topic/hivestreatment