You are probably suffering from hives, also known as urticaria. This is basically an allergy - the red marks and itchiness that you are experiencing are essentially an allergic reaction to some substance in your surroundings or in your diet. Try to think whether there have been any recent additions in your house or to your diet around the time that these symptoms began. However, allergies can develop quite suddenly, so this might be a new reaction to something that never bothered you before. You will basically need to use a method of elimination to find out what it is that you are reacting to. In some cases, this might only be possible with the help of a doctor, preferably one who specializes in allergies.
As with most itching, you should avoid scratching yourself as this only makes the itch worse and can also damage the skin. When you have an outbreak, you can apply cold compresses to the affected area to get some relief. There are other remedies too, such as tamarind juice, oatmeal, and calamine lotion, but they do not work for everyone and may even worsen the reaction, so a cold compress is the safest, at least till you know what the cause of your allergy is.
answered by G R