What is Erythema Infectiosum (Fifths Disease)?
Erythema infectiosum, also known as “fifth disease”, is a common virus-driven illness that usually affects children, particularly those between 5 and 15 years old. It’s called “fifth disease” because it is one of the six most commonly found viral rash illnesses in children. While adults can also get this disease, it’s less common.
The fifth disease is caused by a virus named “human parvovirus-B19”. This virus is also linked to other health problems like aplastic anemia (a condition that occurs when your body stops producing enough new blood cells), polyarthropathy (multiple joint pains), and hydrops fetalis (a serious condition in which a fetus becomes extremely swollen).
People usually catch the fifth disease through droplets when someone with the virus coughs or sneezes. It can also spread through blood contact. It most often occurs in the spring and early summer months. Most of the time, the only treatment needed is to ease symptoms and provide supportive care. But in some situations, like if a pregnant woman becomes infected and it could affect the unborn child (hydrops fetalis) or lead to body’s inability to produce red blood cells (aplastic crisis), special consideration is required.
What Causes Erythema Infectiosum (Fifths Disease)?
Parvovirus B19 is the virus that causes a disease known as erythema infectiosum. This type of virus is unique because it doesn’t have an outer layer, or “envelope,” and it carries its genetic information in a single strand of DNA. It’s part of the Parvoviridae family of viruses.
This virus has a particular attraction to the cells that make red blood cells. Most commonly, people catch the virus by breathing in droplets from an infected person. But, it can also be passed from a pregnant woman to her baby, or through a blood transfusion or blood products.
Risk Factors and Frequency for Erythema Infectiosum (Fifths Disease)
Erythema infectiosum is a disease that affects people all over the world, but it’s more common in school-age children between the ages of 5 and 15. It also affects adults, but less so. This infection is usually seen in the spring months.
When pregnant women get infected with Parvovirus B19, it can lead to serious problems for the baby. These problems include miscarriage, the baby dying before birth, and a condition called hydrops fetalis, which causes excess fluid buildup in the baby’s tissues and organs. The chance of losing the baby after an acute infection is around 5%. Mothers in the second trimester are most at risk, but such cases have been reported throughout pregnancy.
People with diseases that cause long-term hemolytic anemia, like sickle cell disease, can be affected more seriously by Parvovirus B19. The virus destroys young red blood cells, causing a decrease in red blood cell production. Such individuals can develop a condition called aplastic crisis, leading to severe anemia. These patients often appear much sicker, with symptoms like fever, weakness, and tiredness. If they develop an aplastic crisis, they may also have symptoms of severe anemia like paleness, fast heart rate, and rapid breathing.
Signs and Symptoms of Erythema Infectiosum (Fifths Disease)
Erythema infectiosum, also known as the fifth disease, typically starts with mild flu-like symptoms like fever, fatigue, muscle pain, diarrhea, vomiting, and headache. As the illness progresses, a distinctive red rash that looks like a “slapped cheek” appears on the face. The rash can last up to 5 days, and although it’s not usually present in the beginning stages of the disease, it can be the only clue that leads doctors to a diagnosis. Once the cheek rash appears, the person often feels healthy once more, and the initial symptoms disappear. The racing rash appears because of an immune response.
Days after the cheek rash arrives, another rash tends to develop on the body and limbs. It can last about a week and may create a lacy or net-like pattern as it fades. Although it can show up anywhere on the body, it usually avoids the palms and soles. Exposure to sunlight or heat may intensify the rash.
Some people, particularly adults, may experience joint pain alongside or following the rash. This symptom is also believed to result from immune responses and typically affects women more than men. The pain usually appears in both sides of the body and frequently targets the hands, wrists, knees, and feet. People often complain of joint stiffness, but there is no physical joint damage. After around three weeks from the start of symptoms, the joint issue usually resolves. It’s important to note that when these joint symptoms are present, the person is not considered infectious or contagious.
People with weakened immune systems may not develop the rash or joint symptoms because these signs depend on immune responses, and their immunity might not be strong enough to trigger them. These individuals could potentially develop a chronic infection with the virus that causes erythema infectiosum, leading to decreased white blood cells, platelets, or complete bone marrow suppression.
- The rash might feel itchy in adults
- The rash is usually seen in most children, but less than half of adults
- The person is not contagious when the rash is present
Testing for Erythema Infectiosum (Fifths Disease)
Most people with a parvovirus B19 infection don’t need specific tests, as the illness typically resolves on its own and symptoms are mild. However, if there’s a need to establish a diagnosis, a blood test can check for specific antibodies produced in response to the virus.
Testing for specific antibodies called “IgM” can confirm a recent or ongoing infection. Usually, these antibodies are detectable in the blood within 7 to 10 days after coming into contact with the virus. They may stay in your system for 2 to 3 months after the exposure.
Another type of antibody, called “IgG,” starts to increase about 2 weeks after the viral exposure and can be detected throughout life, indicating that the patient is immune to future infections of parvovirus B19. This is important because these antibodies protect against the virus.
This particular test can help doctors confirm a diagnosis in patients who may have a severe form of the disease known as ‘aplastic crisis,’ where the body temporarily stops making red blood cells. The test for IgG antibodies is also often used in prenatal care. Doctors can evaluate a pregnant woman’s immunity to parvovirus B19 to assess the risk of potential birth defects in the baby.
Treatment Options for Erythema Infectiosum (Fifths Disease)
Erythema infectiosum, commonly known as Fifth disease, usually resolves on its own. The main goal of treatment is to ease symptoms and provide essential support to the body’s healing process. Pain relievers, like acetaminophen and Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) can be used to manage fever, joint pain, and headaches, if they occur.
If it turns out that the disease has caused aplastic crisis, a condition where the body temporarily stops producing new blood cells, regular monitoring of hemoglobin and hematocrit levels will be needed. Hemoglobin and hematocrit are measures of red blood cells in the blood; they may require replenishment through red blood cell transfusions during the course of the viral infection.
If a pregnant mother is diagnosed with parvovirus B19, the virus causing Fifth disease, early in her pregnancy, she’ll need to have regular check-ups with her obstetrician. This is to closely monitor for any potential complications to her fetus and to watch for a condition known as hydrops fetalis, where severe swelling occurs in the fetus. Regular ultrasounds will also be done to monitor the baby’s development.
What else can Erythema Infectiosum (Fifths Disease) be?
When a medical professional is trying to diagnose erythema infectiosum, which is also known as fifth disease, they have to consider a number of other conditions that might cause similar symptoms. These include:
- Measles
- Rubella (German measles)
- Roseola
- Scarlet fever
In adults, where joint pain is more common, the diagnosis might need to rule out other conditions like the flu and mononucleosis.
They also need to think about non-infectious causes. These could include things like a reaction to a drug, rheumatoid arthritis, and juvenile idiopathic arthritis.
If joint pain or stiffness goes away after about 3 weeks from when the symptoms first appeared, it can help rule out arthritis-based conditions.
What to expect with Erythema Infectiosum (Fifths Disease)
Erythema infectiosum, also known as fifth disease, usually causes mild symptoms that go away on their own in people with strong immune systems. Some people might not even know they’re sick. However, for those with weakened immune systems or blood disorders, this illness can be more serious. They might have persistent symptoms or develop a long-term infection or anemia, a condition where your body doesn’t have enough red blood cells.
The disease can also pose a risk to unborn babies. If a pregnant woman gets infected, especially during the first 20 weeks of pregnancy, the baby may not survive. It’s important to seek prompt medical attention if you suspect you have this condition, especially if you’re pregnant or have a weakened immune system.
