A petechial rash is made up of tiny red, brown or purple spots that are a result of bleeding from capillaries, according to Mayo Clinic. The spots are not raised, nor do they lose color when pressure is applied.
Petechial rashes can occur anywhere on the body, including the inner surfaces of the mouth or the eyelids. A variety of processes can cause petechiae, which can indicate a minor or very serious condition, according to Mayo Clinic. Prolonged straining, certain medical conditions, infections, medications and injuries can all cause capillaries to leak blood into the skin, thereby causing a petechial rash.