It is most commonly attributed to a low platelet count, which can be seen in aplastic anemia or with certain infections.
Anemia usually refers to a shortage of red blood cells in the body. Aplastic anemia, on the other hand, is characterized by a reduced number of red blood cells, white blood cells, and platelets.
This article explores some of the many possible reasons for a low platelet count and the accompanying rash.
Petechiae marks are less than 3mm in size, while purprura may be between 3mm to 10mm.
Image credit: James Heilman, MD, (2016, May 27).
Aplastic anemia occurs when there is a failure in the bone marrow. Marrow is a spongy tissue inside the bones that produces stem cells. These stem cells end up as red blood cells, white blood cells, and platelets.
Platelets are blood cell fragments that stick together and stop bleeding. When platelet counts are too low, the blood cannot clot normally, and this causes superficial bleeding under the skin.
Normally, there are between 150,000 and 450,000 platelets per microliter (µL) of blood circulating the body. These platelets die off after about 10 days.
If the bone marrow does not continually produce new platelets to replace them, the blood's ability to clot will be affected. This causes bleeding under the skin that appears as a red pinprick rash, which is known as an anemia rash.
Some types of anemia can hinder or even stop blood cell production in the bone marrow. The most common among them is aplastic anemia, which is also known as bone marrow failure. A person can develop or inherit aplastic anemia.
Acquired aplastic anemia
Aplastic anemia is a rare and potentially serious blood disorder. It mainly affects adolescents, young adults, and the elderly. Aplastic anemia is two to three times more common in people from Asia.
Bone marrow can be damaged temporarily or permanently by several factors, including:
- radiation and chemotherapy
- autoimmune disorders
- viral infection
This damage can cause aplastic anemia to develop. If the cause of the condition is unknown, it is called idiopathic aplastic anemia.
Inherited aplastic anemia
Several rare, inherited conditions may cause aplastic anemia. The most common of these is Fanconi anemia.
Approximately 90 percent of people with Fanconi anemia will eventually experience bone marrow failure, which may cause a rash. Aplastic anemia is usually just one of the problems that a person affected by Fanconi anemia will experience.
Iron deficiency anemia
Iron deficiency anemia can cause the skin to become itchy or susceptible to bruising.
Scratched and bruised skin can cause a rash-like appearance on the skin.
An anemia rash may be accompanied by other symptoms of anemia, such as dizziness, prolonged infections, and general weakness.
Image credit: DrFO.Jr.Tn, (2012, July 14.)
A doctor may suspect anemia if other symptoms of anemia occur along with the rash.
A low platelet count that occurs with aplastic anemia may also produce other symptoms, including:
- small bruises on the skin
- nosebleeds and bleeding gums
- blood in the stool
- vision problems caused by bleeding in the retina
- heavy menstrual bleeding in women
Other symptoms of aplastic anemia may include:
- shortness of breath
- rapid or irregular heart rate
- pale skin
- unexplained or easy bruising
Symptoms of anemia due to a lack of red blood cells may include:
- shortness of breath
- cold hands and feet
- chest pain
Anemia may also contribute to frequent or prolonged infections, due to a lack of white blood cells. These types of infection can be severe and even life-threatening.
A doctor will aim to identify and treat the underlying cause of the anemia rash using medical history, a physical examination, and test results.
Establishing a medical history is important to be able to assess potential causes of bone marrow damage, especially in cases of acquired aplastic anemia. These causes may include any of the following:
- exposure to toxins, radiation, or harmful environmental agents
- cancer treatments, such as radiation and chemotherapy
- a history of certain infectious diseases or autoimmune disorders
- infections or inherited conditions
A doctor will look for signs of bleeding under the skin and may feel the person's abdomen to determine whether they have an enlarged spleen. They will also ask about any previous illnesses and will want to know about any medications or supplements a person is taking.
A complete blood count will determine the number of blood cells, including platelets, in a blood sample. Fewer than 150,000 platelets µL is considered abnormally low. Blood tests can also help rule out other causes of bone marrow failure.
If a doctor suspects aplastic anemia, they will likely refer the person to a hematologist - a doctor who specializes in blood diseases and disorders.
The appearance of anemia rash can vary greatly. Petechia and purpura marks are seen in the image above.
Image credit: James Heilman, MD, (2010, October 23).
Any treatment plan needs to address the underlying cause of the anemia rash and to restore the body's blood cell production.
Aplastic anemia can be classified as non-severe, severe, or very severe. This is based on a person's blood count and will help determine the treatment plan. The lower the number of blood cells, the more severe the condition.
Treatment for aplastic anemia may include:
- blood transfusions
- blood and marrow stem cell transplants
Medication may be prescribed to achieve the following:
- stimulate bone marrow
- suppress the immune system
- prevent and treat infections
Outlook and recovery depend on the underlying cause of the anemia rash. Underlying damage to the bone marrow may be temporary or permanent.
Aplastic anemia, the most common underlying cause of anemia rash, is both rare and serious. It can appear suddenly, or it can develop gradually. If it is left untreated, aplastic anemia may get worse over time.
Most people affected by aplastic anemia can be successfully treated, even in severe cases, although this can take time. Some may even be cured.
It is important to see a doctor as soon as any unexplained pinprick red rash appears.