A red rash can appear "on its own", but if it comes together with a fever, one will think about whether it is an infection. If there is a red rash that itches, it is often eczema or hives. If it is red and flakes a lot, psoriasis or fungus is a possibility. If it is red and at the same time pimples, acne or rosacea are possible causes.
Red skin color is most often an expression of increased inflammation in the skin. Inflammation is a way the body tries to repair itself. The blood vessels expand and more red blood flows to the skin, since the skin in inflammation needs more oxygen and nutrients.
A number of skin diseases can cause the skin to turn red; various types of eczema, psoriasis, hives, acne, rosacea, tick bites, infections with viruses, bacteria or fungi.
First of all, you have to find out the reason why the skin is red. The skin disease must then be treated, usually with creams or tablets.