Leukemia is a type of cancer that affects the blood cells and bone marrow, a tissue inside bones where blood cells are made. When someone has this disease, the cells normally produced in the bone marrow, such as white blood cells, which fight infection; red blood cells, which carry oxygen throughout the body; and platelets, which help form blood clots, will be crowded out by abnormal leukemia cells. In addition to symptoms like nausea, fever, fatigue, weight loss, and infections, leukemia can also produce a variety of skin conditions such as bruising, rashes, and bleeding. In other cases, some have no skin conditions, Dr. Forrestel says.
What to know about petechiae
Petechiae: Causes, treatments, and pictures
A petechia pl. Petechia refers to one of the three descriptive types of hematoma differentiated by size, the other two being ecchymosis and purpura. Ecchymosis is defined as hematomas larger than 1 centimetre  and purpura as millimetres. The term is almost always used in the plural, since a single lesion is seldom noticed or significant.
Leukemia Rashes, Infections, and Bruises
Petechiae are tiny purple, red, or brown spots on the skin. They usually appear on your arms, legs, stomach, and buttocks. You might also find them inside your mouth or on your eyelids. These pinpoint spots can be a sign of many different conditions — some minor, others serious.
You may notice red, brown, or purple spots on your skin and wonder the cause. There are many possible reasons you may have petechiae, including viral and bacterial infections, use of certain medications, and serious health conditions that affect your blood. Your doctor can examine the spots and conduct any needed tests to diagnose and treat the cause of petechiae. You should consult with your doctor if you notice petechiae appear, but some cases require more prompt treatment than others. If you have petechiae, you should contact your doctor right away or seek immediate medical care if:.