The erythema infectiosum is a contagious infection of viral origin which is capable of causing fever and rashes by the body. This virus mainly affects children of school age, but can also reach the adult population.
The infectious erythema is caused by a virus called parvovirus B19, which is why it can also be called parvovirus. The infectious erythema is also known by other names, the most common, fifth disease or slapped cheek syndrome.
In this article we will explain what the infectious erythema, what are their symptoms, transmission and treatment options.
As mentioned in the introduction of the article, the fifth disease is a viral infection, the most affected population are children between 5 and 15 years. About 70% of individuals reach adulthood already having antibodies to parvovirus B19, which is why this virus is far less common in this age group. But who could spend the entire childhood and adolescence without becoming infected with the virus, could develop infectious erythema at any point in adulthood.
Parvovirus B19 is a virus that can only infect humans. It is different canine parvovirus infection, which can cause serious infection in dogs, but is completely harmless for humans. Therefore, the human parvovirus does not pass for dogs in the same way as the canine parvovirus is not infectious to humans.
The infectious erythema is the most common form of clinical presentation of parvovirus B19 infection, but it is not the only one. The parvovirus B19 infection is usually benign and asymptomatic in most cases, but can cause severe cases of anemia and bone marrow aplasia in immunocompromised, pregnant patients (severe for the fetus) and sickle cell anemia. In this article we'll stick to just the infectious erythema.
The most common form of transmission of parvovirus B19 is through contact with secretions from the airways. This fact is interesting because many of the patients with infectious erythema may not have respiratory symptoms. Even without sneezing, coughing, runny nose or any other respiratory symptom, you can find parvovirus B19 in large quantities in the saliva of sick patients. This existence of the virus in oral secretions causes the transmission can occur through kissing, droplets of saliva during a conversation (spit) of contaminated hands, contaminated glassware and cutlery, bed linen, etc. Because the virus is able to survive several hours in the environment, transmission through recently handled by infected persons inanimate objects is a very common form of infection.
The patient becomes infectious 5 to 10 days after having been infected and so remains for about 5 days. Because the incubation period may last between 4 to 14 days, in many cases, by the time that the patient is more contagious, it still is asymptomatic. The appearance of the symptoms coincides with the appearance of antibodies, which are responsible for end contagious disease. Therefore, in general, when the patient presents the classic skin eruptions no longer is more contagious.
Other form of transmission of parvovirus B19 is called vertical transmission, which is one that occurs from mother to fetus. A woman who has never had infectious erythema and becomes infected during pregnancy can transmit the virus to the fetus. If this transmission occurs in the first 20 weeks of pregnancy, there is an increased risk of miscarriage.
Pregnant women who have had contact with parvovirus during childhood, even if they have not developed symptoms, are immune to the virus and are not at risk of having problems during pregnancy.
Parvovirus B19 can also be transmitted through blood transfusion.
Most patients who have contact with the first B19 does not develop any symptoms. Others have very mild, similar frame with any common cold. The result is that while 70% of adults have already had some sort of contact with the virus, only a minority is aware of this fact.
In patients who develop symptoms of infectious erythema, the picture begins as a non-specific virus, with common symptoms, runny nose type, low fever, sore throat, sneezing, headache, cough, malaise, itching in the body and joint pain. This initial framework, called the prodrome, lasts 2-3 days and then disappears.
Two to seven days after the prodromal stage, the symptoms returned, this time in the form of skin rash, called rash or a rash. The rash of infectious erythema typically behaves in three phases.
Phase 1 - the rash starts on the face, giving the patient an appearance of "slapped face". This rash is characteristically reddish well, affecting both cheeks and discreet relief. In general, the areas around the nose, mouth and eyes are spared.
This facial rash is more common in children than in adults and usually lasts 2-4 days. It is not painful, but can cause some itching.
Phase 2 - 1 to 4 days after facial rash, rash spreads throughout the body. At this stage, the skin lesions acquire a very characteristic appearance, which is called the reticular rash or rash in the form of income, as can be seen in the next photo. The reticular rash is more common in children than in adults.
In adults the symptoms of erythema infectious may be different. In rash often do not have the typical reticular appearance, can be easily confused with rash of measles, scarlet fever or skin allergies, even some adults may not develop a rash.
While more than 75% of children have rashes, less 50% of adults do.
In some people, especially adult women, the most important symptom, and sometimes only, the parvovirus B19 infection is an intense joint pain, usually with signs of arthritis (pain, heat and swelling in the joints). Hands, wrists, knees, ankles and feet are the most affected sites.
The joint involvement usually lasts 1-2 weeks, but in some cases it may take months to go away completely.
Phase 3 - after the acute phase of the rash, which lasts 1-3 weeks, the patient can still spend weeks, or even months, experiencing rash of recurrences, especially after contact with hot water, excessive sun exposure, very hot days, stress psychological or strenuous exercise.
After curing, the patient becomes immune to the disease.
When the clinical picture is very characteristic, with facial rash type slapped and reticular rash on the body, the diagnosis can be made only clinical form, through the symptoms.
In cases in which there are doubts, the physician may request a serological test for parvovirus B19, which is a blood test that searches for antibodies against the virus. When the patient has skin lesions and / or joint pain, usually already have specific antibodies against parvovirus B19 in the circulating blood.
In the vast majority of cases, the infectious erythema is a benign and self-limiting disease, which heals by itself without the need for any treatment.
If the complains of itching patient or joint pain, symptomatic medications such as an antihistamine or analgesics may be prescribed to relieve symptoms.
