A couple of questions: Did the doctor offer an opinion or advice? Are you eating properly and drinking plenty of water? Have you gained any weight recently? Are you bathing daily?

If your skin is going through a dry period then it’ll itch most after a shower/bath (soap) and also after sweating because sweat stings dry, taut skin that usually has fine tears. At night could be because of air on you, either a/c, a ceiling fan in your room or whatever. Get yourself a non comdegenic skin moisturizing lotion and slather it on at night. Get one with sunscreen in it for the daytime. As dried up, peeling/sloughing skin gets moisturized by the lotion then it’ll lift and roll off easier each time you bathe.

Don’t scratch. Each time you scratch then you make more tiny tears in the already dry skin which will irritate the fresh skin below and sometimes cause an infection or rash just because of everyday stuff on your fingers like dust, food residue, detergents. If you have time then soak in a tub of just barely warm water, no soap though. Towel off and then slather up in lotion all over, take a nap and let the stuff soak in.

My skin changed fequently when I was pregnant. It was annoying, but basically harmless. @Neizvestnaya has good advice.

How old are you? Are you under any unusual stress? Among the possibilities are stress-induced eczema and shingles.
http://www.checkshinglessymptoms.com/
Eczema tends more to be in isolated spots, while shingles is more overall but particularly around the head and neck. Post more information if you want more precise suggestions.

@GeorgeGee : The OP is pregnant and 20.

Stress can cause all sorts of physical problems including rashes and skin problems. I would go back to the doctor and tell him if you’ve been under any kind of stress and ask him if you need to get a consult with a dermatologist. Tell him about any changes you have made in your diet or with the fabrics and products you use in your house.

Possible culprits: have you changed your detergent, shampoo, soap or lotions lately? Have you been wearing a new kind of fabric or put a different kind of sheets or blankets on your bed? Those things can cause problems. You may be allergic to something new in your environment. It could also be caused by some new food you may have introduced into your diet. Do you have pets? Usually the hot weather is what brings the fleas and their microscopic offspring into your house. Sometimes you can’t even see them. Another posibility is bed bugs (also very small) which have been infesting the U.S. lately. Have you stayed in a hotel recently? Also, if it’s hot, you may have something called prickly heat but that is usually something that bothers you on the rear end and other covered areas.

Another potential problem is psoriasis which can be brought on by stress.

Go back to the doctor, give him all the facts you can think of. If he just blows you off, ask for a dermatologist consult, or ask to see a different primary care physician. Good luck. Feel better.

@JilltheTooth: If the OP is pregnant then the itching and rash could easily be because she’s sharing nutrition with the podling and weight gain stretches the skin which makes it itch. She needs enough water and fats in her diet for them both.

It could be psoriasis. The skin on top of my right index finger had this problem a few years ago, but it cleared up. Sometimes exposure to sun aggravates the condition. Get it checked by your family doctor. He will refer you to a dermatologist. Here’s some info on the condition——
http://www.psoriasisconnections.ca/en/learn/what-is-psoriasis.jsp?source=google&group=symptoms&gclid=CMnmw4yU7aQCFRD75wodajh51A

With out knowing more, it is difficult to be sure what is going on with you. But here are a couple of natural cures for skin rash that can be very helpful. If you are wearing any kind of jewelry that might have the metal, nickel in it, try not wearing for a few days or a week and see if that clears it up. Blend some dry oatmeal and put it in your bath. It is great for your skin and often can help end itching. Mix apple, grape, pineapple and carrot juice and drink at room temperature. This mix is very good for your skin. Stress can sometimes be a problem that contributes to many chronic conditions including skin rash. Try meditation in the morning and again in the evening to relieve stress. With a little practice you will begin to notice improvement in a number of area’s of your health.

The reason for the red pimples which is a reply to what does heat rash look like is that the over exposure to heat might make the internal skin have a burning or an itching sensation that further grows in it size and forms pimples in the body in different parts.
http://www.biblehealth.com/heat-rash/heat-rash-overview.html