The spleen is an organ that removes damaged red blood cells from the bloodstream. It also protects the body against bloodstream infection by removing bacteria from the blood. If the spleen is surgically removed or does not work correctly, a minor infection can potentially develop into a life-threatening infection known as sepsis. Fortunately, treatments to prevent minor infections from becoming life-threatening can be effective when taken as soon as symptoms appear.
This topic reviews how the spleen works, why it might be removed or not function correctly, and ways to prevent serious infections.
WHAT IS THE SPLEEN?
The spleen is an organ located in the upper left side of the abdomen that filters bacteria from the bloodstream and is important for fighting infection (figure 1).
Reasons the spleen may be removed or not function — The spleen may be surgically removed for a number of reasons, including:
●The spleen has been damaged by an injury, accident, or abdominal surgery
●To treat an underlying medical condition such as thrombocytopenia (low platelet levels), certain leukemias, or lymphomas
●Overactivity of the spleen
In other cases, the spleen may not work properly due to an underlying condition such as:
●Sickle cell disease or another inherited blood disease
●Disease or conditions in which there are abnormalities in the breakdown of red blood cells
●Collagen vascular diseases, such as systemic lupus erythematosus (rare)
●Absence of the spleen at birth (rare)
WHAT IS SEPSIS?
Sepsis is a severe and potentially life-threatening condition in which infection-causing bacteria spread throughout the bloodstream and/or tissues and impair normal body functions. In people whose spleen is removed or does not function properly, the most common cause of sepsis is infection with a bacterium called Streptococcus pneumoniae, also known as the pneumococcus. (See "Patient information: Pneumonia in adults (Beyond the Basics)".)
Less commonly, sepsis develops as a result of infection with other bacteria, such as Neisseria meningitidis or Haemophilus influenzae type B (Hib). N. meningitidis and Hib were previously common causes of meningitis and other serious infections in children before vaccines to prevent these infections became available. Hib can also cause upper respiratory tract infection.
Symptoms of sepsis — In people without a spleen or with abnormal spleen function, symptoms of sepsis may develop quickly following a minor infection, such as a respiratory tract infection. Early symptoms of a respiratory infection can include throat or chest pain, coughing, ear pain, or sinus pain and congestion, sometimes accompanied initially by low-grade fever.
In other cases, sepsis develops abruptly without any early symptoms. Symptoms can become severe quickly. People without a functional spleen should begin antibiotic treatment and seek medical care at the earliest sign or symptom of sepsis (see 'Antibiotics for fever' below), including the following:
●Fever greater than 100.4ºF or 38ºC
●Uncontrollable chills and/or shivering
●Drowsiness, confusion, and/or disorientation
●Nausea, vomiting, and/or diarrhea
●Severe abdominal pain
●Pinpoint purplish red spots on the skin (petechiae) or larger, bluish bruises
●Low blood pressure, lightheadedness, or fainting (syncope)
●Rapid heart rate
Risk of sepsis — If the spleen stops working normally or is surgically removed, the body’s immune system can usually compensate. However, there is a small but significant risk of sepsis.
The risk of sepsis is highest in the following groups:
●Children whose spleens are removed during infancy
●People with lymphoma who are treated with splenectomy, radiation, and chemotherapy
Sepsis can also develop in otherwise healthy adults who have had their spleen removed, particularly in the first few years following splenectomy. The lifetime risk of sepsis after splenectomy is about 1 to 2 percent.
Fortunately, taking certain precautions can reduce the risk of developing sepsis. (See 'Preventing sepsis' below.)
All people without a functional spleen are advised to take certain precautions to help reduce the risk of developing sepsis.
Inform healthcare providers
●Inform all doctors, dentists, and other members of the healthcare team that the spleen has been removed or does not function properly, especially when seeing new providers in an urgent care setting or emergency ward.
●Carry a patient identification card, a Medic Alert bracelet or necklace, or other medical identification indicating that the spleen has been removed or does not work properly.
Immunizations — Experts recommend that people without a functional spleen have certain vaccinations to reduce the risk of sepsis. Although these vaccines do not prevent all infections with pneumococcus, Haemophilus influenzae type B (Hib), and meningococcus, they can protect most people and reduce the severity of infection in others. When possible, vaccines should be given at least two weeks before planned surgical removal of the spleen. The vaccine should be given 14 or more days after emergency removal of the spleen (eg, due to trauma). The following recommendations are intended for people in the United States without a functional spleen; recommendations in other countries may differ:
●Pneumococcal vaccine – The pneumococcal vaccine is recommended for all people who do not have a functional spleen. Two types of pneumococcal vaccines are available, PPSV23 and PCV13. Young children receive PCV13 as part of their routine infant immunizations. PCV13 is also recommended for adults who do not have a functional spleen. In addition, PPSV23 is recommended for adults and children ≥2 years who do not have a functional spleen. When possible, PPSV23 is given at least eight weeks after PCV13 immunization. (See "Patient information: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)" and "Patient information: Adult vaccines (Beyond the Basics)".)
●Hib vaccine – Most adults have been exposed to Hib and are therefore immune. However, because there is a small risk that the person is not immune, experts advise people without a functional spleen to have the Hib vaccine if it was not given previously (it became available in the United States in 1988). If a person is unsure if the vaccine was given during childhood, a blood test can be done to determine if he or she is immune. (See "Patient information: Adult vaccines (Beyond the Basics)".)
●Meningococcal vaccine – The meningococcal conjugate vaccine (MCV4, Menactra or Menveo) is recommended for people without a functional spleen who are between 2 and 55 years of age. People who are greater than 55 years of age should be given the meningococcal polysaccharide vaccine (MPSV4, Menomune).
●Influenza vaccine – Influenza (the flu), a highly contagious viral infection, is a common cause of pneumonia and other bacterial infections. Therefore, a once-yearly influenza vaccination (usually given in the fall) is recommended for people without a functional spleen. (See "Patient information: Influenza symptoms and treatment (Beyond the Basics)".)
Booster vaccines — Additional ("booster") doses of the pneumococcal and meningococcal vaccines may be recommended to help maintain immunity. The need for a booster depends upon the individual’s situation and the type of vaccine previously given. A booster dose of the Hib vaccine is not routinely needed but is occasionally given to those who do not develop a good antibody response to the vaccine.
Preventive antibiotic therapy — Antibiotics are recommended in some people without a functional spleen to reduce the risk of developing sepsis. Two approaches are common:
●Daily preventive antibiotic therapy
●Antibiotic therapy for fever when needed
Daily therapy — Taking an antibiotic on a daily basis can significantly reduce the risk of infection and death, especially in children who have undergone splenectomy. Children with sickle cell anemia who have impaired spleen function may also benefit from daily antibiotic treatment. Because the risk of sepsis is low in adults, the value of daily antibiotic treatment for adults is debated.
The ideal duration of daily therapy for children remains unclear. Many experts advise treatment of children for three to five years after splenectomy (or until adulthood).
Antibiotics for fever — People without a functional spleen are usually advised to keep a full course of antibiotics on hand in case of illness. The antibiotic should be taken at the first sign of infection, such as fever, chills, sore throat, or cough. After taking the first dose, the person should seek care IMMEDIATELY at the nearest urgent care facility to determine if further testing or treatment is needed.
Recommendations for international travel — Before traveling abroad, people without a functional spleen should consult their healthcare provider or a travel medicine center. In some cases, additional vaccinations will be recommended; one or more medications may also be prescribed to prevent or treat certain travel-related infectious diseases. (See "Patient information: General travel advice (Beyond the Basics)".)
Babesiosis is a tick-borne infection that is caused by a parasite. If infected with babesiosis, people without a functional spleen can develop a flu-like illness leading to potentially life-threatening complications. Treatment for babesiosis is available and is usually effective.
In the United States, most cases of babesiosis have occurred in the following areas:
●Coastal areas and islands off of Massachusetts, particularly Cape Cod, Nantucket, and Martha’s Vineyard
●Islands near New York City, particularly Long Island, Shelter Island, and Fire Island
●Block Island, off of Rhode Island
●Focal areas in Connecticut
There have also been reports of infection in New Jersey, Minnesota, Maryland, Virginia, California, Washington State, Georgia, Wisconsin, and Indiana.
Measures to avoid tick bites and steps to take after a tick bite are described in detail in a separate topic review. (See "Patient information: Lyme disease treatment (Beyond the Basics)" and "Patient information: What to do after a tick bite to prevent Lyme disease (Beyond the Basics)".)
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
This topic currently has no corresponding Basic content.
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Pneumonia in adults (Beyond the Basics)
Patient information: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)
Patient information: Adult vaccines (Beyond the Basics)
Patient information: Influenza symptoms and treatment (Beyond the Basics)
Patient information: General travel advice (Beyond the Basics)
Patient information: Lyme disease treatment (Beyond the Basics)
Patient information: What to do after a tick bite to prevent Lyme disease (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Approach to the adult patient with splenomegaly and other splenic disorders
Assessing the immunologic response to vaccination
Clinical features and management of sepsis in the asplenic patient
Prevention of sepsis in the asplenic patient
The following organizations also provide reliable health information.
●National Library of Medicine
(www.nlm.nih.gov/medlineplus/ency/article/002944.htm, available in Spanish)
●Children’s Hospital of Boston