Fever with thrombocytopenia is usually due to an infection, often from mosquito or tick bites. Treating the infection typically resolves thrombocytopenia, but certain infections may have a less favorable outlook.

Platelets are tiny cell fragments that make up the blood. Also known as thrombocytes, they help form clots that stop a wound from bleeding. If you have thrombocytopenia, it means your platelet levels are very low.

Fever is a common symptom of infection. Sometimes, it occurs alongside thrombocytopenia. Keep reading to learn which infections can cause fever with thrombocytopenia and how doctors diagnose this condition.

Severe fever with thrombocytopenia syndrome (SFTS) is a specific infection that results from the SFTS virus, which scientists first identified in 2009.

Transmission of the SFTS virus occurs through tick bites, notably from tick species in several Asian countries, including China, Japan, and South Korea.

If a tick with the SFTS virus bites your skin, you could contract SFTS. It’s also possible to get it from close contact with someone who has the virus.

Some signs and symptoms of SFTS include:

Treatment for severe fever with thrombocytopenia syndrome

As SFTS progresses, it can lead to multiple organ failure and death. Although there’s currently no cure, treatments can help your immune system fight the infection and ease your symptoms.

Possible treatments for SFTS include:

Several other infections can cause both a fever and low platelets. Some of the most common ones include the following.

Malaria

Malaria is a mosquito-borne illness common in warm, wet climates around the world. It causes a high fever, chills, shaking, and gastrointestinal symptoms such as nausea, vomiting, and diarrhea.

Thrombocytopenia is common among people with malaria infections. The authors of a 2021 study reviewed 73 confirmed cases of malaria from a hospital in Ethiopia and found that 79.5% of people with malaria also had some form of thrombocytopenia.

Dengue

Dengue fever is another viral infection that mosquitoes commonly transmit. It’s mostly prevalent in tropical regions and can cause a high fever, body aches, and a skin rash, among other symptoms.

Thrombocytopenia is a common complication of severe dengue that can sometimes also lead to bleeding in the nose, gums, or intestines.

Leptospirosis

Leptospirosis is a virus common among animals such as dogs, rodents, and livestock. Humans can get it through contact with the urine of an infected animal.

Although leptospirosis often causes a mild, flu-like illness, symptoms may worsen over several weeks. Thrombocytopenia is more common with severe cases of leptospirosis.

Typhoid

Typhoid fever is a bacterial infection that spreads through contaminated water and food. It causes a high fever along with weakness, pain, fatigue, and other symptoms.

Without treatment, typhoid fever can lead to severely low platelet levels, as well as life threatening symptoms such as intestinal bleeding and sepsis.

Septicemia

Septicemia is a severe blood-related complication of a bacterial infection in another part of your body, such as pneumonia or a urinary tract infection. It occurs when bacteria enter the bloodstream and start to spread rapidly, triggering widespread inflammation and sepsis.

Septicemia doesn’t always cause low platelets. But when it does, it’s often a sign of a less favorable outlook, according to the authors of a 2022 review.

Other viral infections

Research links several other viruses to fever with thrombocytopenia, including:

A doctor will start by asking you about your symptoms and medical history and conducting a physical exam.

If they suspect you have thrombocytopenia, they’ll take a blood sample to check your platelet levels. Healthcare professionals can also use a blood test to diagnose most of the viruses that cause fever with thrombocytopenia.

After a healthcare professional determines the cause of your symptoms, they’ll begin treatment to address the underlying cause, which is usually an infection. This often resolves thrombocytopenia symptoms.

In rare cases, doctors may recommend platelet transfusions to increase your platelet count.

In a 2018 study, 95% of people ages 14 years and over with fever and thrombocytopenia recovered. Deaths from the condition were rare and mostly due to sepsis or effects on multiple organs.

The outlook for people with SFTS specifically may be less favorable, with death rates ranging from 16% to 46%, according to one 2023 study. People with SFTS were more likely to die if they experienced tremors, convulsions, or coma.

Can fever lower your platelet count?

A fever can lower your platelet count, but it depends on the infection causing the fever. Certain viral infections that cause fever also attack and destroy platelets, triggering low platelets.

Is fever a symptom of ITP?

Fever isn’t usually a symptom of idiopathic thrombocytopenic purpura (ITP), a blood disorder that causes low platelet levels. People with ITP experience chronically low platelet levels and don’t usually have other signs of infection.

Many infections cause fever, which can occur alongside a wide range of other symptoms. Sometimes, an infection can affect your platelet levels.

Thrombocytopenia, or low platelets, may indicate a more serious viral or bacterial infection that’s causing your body to struggle to replenish platelets.

Some common causes of fever with thrombocytopenia include the SFTS virus, malaria, and dengue. If you’re traveling to a part of the world where these infections are common, talk with a healthcare professional to learn what you can do to protect yourself.