Fifth Disease (Erythema Infectiosum)

What is Fifty Disease?
Erythema Infectiosum also known as Fifth Disease is caused by Human Parvovirus - B19 (PV-B19), which is an erythrovirus. This disease is common in children between the ages 4 to 16. The very distinctive nature of this disease shows up in the form of red rashes on the patient’s cheeks and appears as if the patient has been slapped or hit on face. This disease spreads across the other parts of the body like legs, trunk and arms etc. Infection of this disease in children is very self limiting and the patient starts recovering after some time without development of more complications.

This disease is referred as Fifth Disease as it is the fifth number disease recognized in a group of diseases which cause rashes in children.

Who develops this disease?
The ratio of males and females getting infected with this disease is almost same. This disease is prevalent in children and does not cause much harm to them as the patient recovers in a very short period without developing more complications.

This disease in adults (especially those who have damaged immune system and pregnant women) may get much more complicated than in children and the result may vary depending on the extent of complications.

(This disease causing virus Parvovirus is different than the Parvovirus found in animals and it does not convert/transform to the human form of virus and vice versa.)

Causes and symptoms of fifth disease:
As discussed earlier, Human Parvovirus-B19 causes fifth disease in humans. The patient is considered infectious during the incubation period of the disease which involves the initiation and development of the disease after which the symptoms starts showing up till the time when the disease matures in the patient. This disease is considered to be transmitted mainly through the body fluids from the infected patient. The body fluid is also considered to transmit when the patient coughs or sneezes and an un-infected person comes in vicinity enough for him/her to get infected.

The disease is also transmitted through blood transfusion or through blood products. It also spreads from an infected mother to her fetus.

The symptoms of this disease include:
1) The patient may experience headache, mild fever, pharyngitis, malaise etc. in the initial phase of the disease.
2) Some patient’s may also experience problems such as diarrhea, nausea, pain in abdominal area, arthralgias etc.
3) In the first stage of the disease patient’s skin begins to appear reddish (cheeks, arms and legs etc.) and gives an impression of being slapped. The erythematic marks appear abruptly on the skin and they start fading in about 4 to 5 days.
4) In the next stage of the disease, an erythematous eruption starts occurring on the patient’s skin targeting the exterior surfaces of the skin (this stage lasts for about 4 to 6 days). This pattern slowly converts into reticulated pattern of patches/blotches on the skin of the patient which may last from 3 to about 22 days.
5) As compared to the children if an adult is exposed to the virus Parvovirus-B19, the disease shows different characteristics and slight different symptoms. The most common symptom experienced by an adult suffering from this disease involves symmetric joint pain, which increases over the period.
6) Patient’s suffering from fifth disease may also experience reddening of eyes, swelling of glands, problems related to throat such as soar throat and joint pain (as mentioned earlier).

What are the complications associated with the fifth disease?
The disease in adults may get more complicated over the period as compared to in children.
People with weakened immune system and with a background of shortened life span of red blood cells are prone to conditions such as prolonged viremia leading to damaged bone marrow cells and other complications. PV-B19 virus may also trigger or cause diseases like papular-purpuric gloves and socks syndrome, systemic sclerosis, acute vasculitic syndromes, rheumatoid arthritis, hemocytophagia, systemic lupus erythematosus, myocarditis, hepatitis, idiopathic thrombocytopenic purpura, anemia, pulmonary diseases, erythematos exanthema (atypical), ileitis, neurological problems, nephrotic syndrome, thalassemia, sickle cell anemia, Pyruvate Kinase deficiency etc.
Infection of the PV-B19 virus in pregnant women may lead to a direct cyto-toxic effect on fetal red blood cells and other problems such as congestive heart failure, anemia, hydrops fetalis and miscarriage etc. The anemia and other complications may also be passed to the fetus.

Test and diagnosis of the disease:
The reddish rashes on patient’s body and skin can help doctors in diagnosing the disease. Other than the physical examination of the patient, doctor also may opt for few tests such as blood test, IgM assays which involve immunoassyas and radioimmunoassay, Loop-Mediated Isothermal Amplification test, Dot-Blot Hybridization and Polymerase Chain-Reaction etc.

What are the treatments available?
Treatment of the disease varies based on various parameters such as the age group, to which the patient belongs, patient’s immune system etc. Doctor may also prescribe medicines or lotion based on the stage of the disease.

How should I prevent this disease?
As the initial symptoms of the disease take some time to show up and this period falls under the period in which this disease can spread from the infected person to a healthy person (also known as the period between infection and incubation), it is very hard to baseline the preventive measures against this disease. However, children should be advised to keep hygiene and not use each other’s used tissues or handkerchiefs etc. They should also be careful while interacting with sick children.