A common skin condition associated with leukemia looks like tiny red spots. The red spots, which can also appear purple or brown, are known as “petechiae,” a term derived from an Italian word for small freckle. It’s pronounced (puh-TEE-kee-ee).
In most cases, petechiae resolve on their own within a few days of onset. In severe cases, or if caused by an underlying pathological condition, petechiae may persist or spread quickly over the entire body unless the underlying cause is addressed.
Read on to learn why leukemias, including chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), and acute myeloid leukemia (AML) may cause these spots – and when you should seek medical attention.
The appearance of petechiae can vary from person to person. On fair skin, petechiae may look like tiny red, purple, or brown dots no larger than two millimeters in size and involve flat, unraised skin. On darker skin tones, these spots may be brown and more difficult to see.
“They are not raised or rough, and they are painless,” said Tara Graff, DO, MS, a medical oncologist with Mission Cancer and Blood in Des Moines, Iowa.
One way to test whether the red dots are a rash or petechiae is to press on the dots. When you press on petechiae, the dots will remain red, purple, or brown. With a rash, the dots will turn lighter.
Unlike rashes, petechiae are distinctive in that they appear in specific parts of the body where blood is most likely to accumulate. The spots are generally found in the lower extremities or trunk, Dr. Graff said. “They can be anywhere, but usually the trunk and legs are common sites.”
Despite the seemingly benign etymology of the term, petechiae are not to be dismissed without concern. These spots occur because of tiny broken capillaries under the skin or bleeding under the skin. Typically, platelets help your blood to clot. But with leukemia, your body does not have enough platelets to seal off the broken blood vessels.
“Petechiae are essentially damaged blood vessels or bruises that appear on the skin,” said Daniel Landau, MD, oncologist, hematologist, and contributor for The Mesothelioma Center at Asbestos.com. “[They] often occur when someone has low platelets.”
However, petechiae can occur for other reasons, too. Some non-leukemia-related causes include:
Endocarditis
Infections like strep throat or Rocky Mountain spotted fever
Heat rash
Cherry angiomas
Contact dermatitis
Ringworm (tinea corporis)
Atopic dermatitis (eczema)
Medications, like antibiotics
Pityriasis rosea
Blood spots (purpura)
Swimmer’s itch
Psoriasis
Lichen Planus
Injury
Pimples (acne vulgaris)
Vitamin C deficiency
Thrombocytopenia
Dismissing the tiny red dots as just eczema or razor burn can have devastating consequences. Petechiae are not a rash but rather a cluster of tiny red dots, Dr. Graff said. They can signal serious conditions and should be evaluated by a doctor. However, it’s possible to misdiagnose petechiae as a general rash or other skin condition.
Like petechiae, purpura is characterized by clusters of red or purple spots on the skin that don’t change color when pressed. However, the difference lies in size – purpura spots are larger, measuring between four and ten millimeters in diameter. Purpura may also be accompanied by bruising or discoloration of the skin. It can indicate an underlying medical condition such as a blood disorder or vitamin C deficiency.
Cherry angiomas are small red bumps on the skin caused by an overgrowth of tiny blood vessels. They are generally harmless and more common as people age. Blood spots, also known as purpura or senile purpura, are like cherry angiomas but tend to be larger in size and may appear purple or brown. These spots can occur in individuals with fragile blood vessels or thin skin.
You can tell the difference between petechiae and these conditions by pressing on the spots. If they don’t change color or disappear, it’s more likely to be petechiae caused by a blood disorder. Cherry angiomas are raised bumps that may bleed if scratched, and blood spots will typically fade within a few days.
Eczema is a common skin condition characterized by red, itchy patches that often develop into blisters or scaly areas. Unlike petechiae, eczema does not typically present as tiny dots but rather larger patches of redness, dryness, and irritation. It’s common in people with allergies or asthma and can be triggered by irritants or stress.
Psoriasis also causes red, scaly patches on the skin. These patches may be mistaken for petechiae due to their red color, but they are typically larger and thicker. Psoriasis can also cause joint pain or inflammation in some individuals.
Unlike petechiae, psoriasis lesions may temporarily lose color when you apply pressure to them, and they often appear on the scalp or joints rather than just the trunk or extremities.
Petechiae isn’t the only rash that can be caused by leukemia. Leukemia rashes can also appear as red, itchy rashes or hives on the skin. One example is leukemia cutis, which is seen in approximately 5% to 10% of leukemia patients. Unlike petechiae, which are red or purplish in color and flat, these are bumpy growths. “The leukemia cells are infiltrating skin or mimicking this,” Dr. Landau said.
Other possible leukemia rashes include:
Sweet syndrome: A rare skin condition characterized by raised, tender red or purple spots on the arms, legs, face, and neck. Some leukemia treatments can cause this condition.
Blastic plasmacytoid dendritic cell neoplasm (BPDCN): A rare type of leukemia that presents as skin lesions and can be mistaken for other skin conditions.
Mastocytosis: An overproduction of mast cells, a type of white blood cell, which can cause rashes and other skin symptoms.
Chloroma: Also known as granulocytic sarcoma, this is a rare type of leukemia that can cause green or blue skin lesions.
Abnormal bruising: Some people with leukemia experience abnormal bruising, which can also be a sign of low platelets. These bruises may appear on the skin or under the nails and can be larger than petechiae spots.
“Sometimes the first sign someone has of bone marrow failure or leukemia is the petechiae that appear on the skin,” said Dr. Landau. However, other symptoms may also be present, such as:
Fatigue
Fever or night sweats
Frequent infections
Shortness of breath
Frequent nose bleeds
Pale skin
Bruising easily
Unexplained weight loss
Bone pain
Joint pain or tenderness
Swollen lymph nodes
Pain or full feeling under your ribs on the left side
Enlarged liver and spleen
Leukemia often presents with very minor symptoms that can easily be attributed to something else, so an annual checkup with blood work can often detect its presence. However, if you are experiencing any of these symptoms and are concerned, then you may want to speak with your doctor.
The good news is that once proper treatment begins for the underlying cause – in this case, leukemia – the petechiae go away.
“They stop developing when the platelet count increases,” according to the National Cancer Institute’s SEER leukemia training module. The petechiae evolve from red to brown and eventually disappear. Treatments, such as chemotherapy, radiation, immunotherapy, or a bone marrow transplant, can help restore normal platelet function and resolve petechiae and other symptoms of leukemia.
If you have petechiae, you should take extra caution in protecting your skin. Avoid harsh chemicals or scrubbing the skin too vigorously, which can cause further irritation. You should also avoid activities that may cause bruising or cuts, such as contact sports. Petechiae should be addressed promptly to ensure any underlying causes are properly diagnosed and treated.
Most cases of petechiae are not cause for alarm, but it’s always important to monitor your skin and seek medical attention if you have any concerns.
