It was late morning, just before lunch. Grabbing the chart of my next patient I noticed that he was not on the schedule.

 

Six-year-old Tyler had been sent home from kindergarten because the teacher noticed he had a rash. Mom was apologetic for not having an appointment. She explained the school had called her saying that she had to pick Tyler up and get a doctor’s note stating when he could return to school. She thought she’d stop by the office hoping to see if we could squeeze him in.

 

When I walked in the room I had a pretty good idea what the diagnosis was.

 

Tyler had no complaints and really did not have any symptoms. He had no fever and looked quite good. On exam he had no specific findings. His cheeks were flushed and there was a subtle almost blotchy rash on the arms. I told mom that Tyler had Fifths disease. The teacher had mentioned something about that. There had been a couple of other students who also had this. She was told he could not return to school without a doctor’s note because he was contagious.  

Fifths disease, or Erythema Infectiousum (EI) is a viral illness caused by the virus Human Parvovirus B 19.

 

It got its name Fifths disease during the early 1900’s when medical experts were classifying illnesses that caused rashes. Number 1 was measles, number 2 was scarlet fever, number 3 was German measles (rubella), number 4 was Dukes disease, number 5 was Erythema Infectiosum and number 6 was roseola…hence the name “Fifths disease”. EI is very common in the spring and summer months. Despite its name “Parvovirus” it has nothing to do with dogs and only affects humans. It is typically a mild, self-resolving disease with little symptomatology. It usually affects children between the ages of 5 and 15 years, but it can also occur in adults.
 

There may possibly be a mild prodrome of symptoms such as low-grade fever, joint aches, runny nose or mild cough. However, this often goes unnoticed.

 

About 20% of patients have NO symptoms at all. A few days later the rash appears on the cheeks. It is described in the old literature as a “slapped face” rash. The cheeks are symmetrically flushed. After a few days there may be a rash on the trunk and extremities that is lacy or reticular. It is often flat and subtle, but it may be raised, occasionally causing itchiness. The rash on the trunk gradually spreads centripetally, It goes down the area and legs over a matter of a few days before it disappears. The entire duration of EI is around 1-3 weeks. The body rash of EI is superficial. When the patient is exposed to heat such as a hot bath or shower, or plays hard on a hot day, the rash may seem more florid, intense and noticeable.
 

While EI is highly contagious, the period of communicability is the time BEFORE the rash starts.

 

Once the rash is first noticed the patient is no longer shedding the virus. There are usually no symptoms once the rash starts. There may be mild joint aches in around 10% of children which can be treated with an NSAID such as Ibuprofen. If there is some itchiness use Zyrtec or Benadryl.

 

Once one gets EI the body produces antibodies against the virus which should confer lifelong immunity meaning you should only get it once.

 

Adults can get EI. While it follows the same time line as children, adults may have more noticeable symptoms of fever and joint aches, especially the larger weight bearing joints such as knees and ankles. EI is a mild, self-limiting illness in most cases. But it can be more serious for certain individuals such as patients who are immune-compromised or patients with sickle cell disease. EI can also be of concern for pregnant women particularly in the 2nd trimester as this may increase the risk for a miscarriage.
 

Getting back to Tyler, he looked fine and I told mom that EI is one of the few diseases where one can make the diagnosis as soon as they walk in the room.

 

I assured her that he was NOT contagious and could return to school that afternoon with a written note to that effect…much to the chagrin of Tyler who had planned to play Minecraft all afternoon.