No magic wand is going to work with this virus… The only thing magical about Erythema Infectiosum, is the rash appearing out of nowhere. Erythema Infectiosum is a virus, aka Fifth Disease, and also “slapped cheek” disease. If you’re a HP fan, you understand my enthusiasm with the verbiage. Here’s an interesting fact about Erythema Infectiosum for you, it’s called Fifth Disease because it was the 5th documented childhood virus many years ago when all those childhood viruses, like measles, rubella, and scarlet fever were being documented.

Today, I thought… it’s time to write a post about Erythema Infectiosum, because I saw a 12 year old with a “lacy” rash; and just days ago, my cousin sent me pictures of her 4 year old with a rash… They both had Fifth Disease. So, that tells me it’s time for a post on Parvovirus B19. Doesn’t that sound disgusting? It’s not really a big deal, as long as you are healthy and not pregnant. This is NOT the parvovirus that animals get.

In healthy kids, Erythema Infectiosum/Fifth Disease is a rather benign ailment. Some kids have it, and you don’t even know it. Many kids get a fever and upper respiratory infection/URI symptoms (cough, congestion, headache, runny nose) before the rash. Some have no symptoms at all and just break out in a rash. And then, some have such a mild case, symptoms go completely unnoticed. Regardless, the virus leaves antibodies behind that are quite important for girls (more on this below). The rash may last for a few days to weeks, but may be more noticeable when the skin is hot from physical activity, hot bath water, etc.

You may be wondering what a “lacy” rash looks like…

Here ya go…Miss Molly’s legs and arms matched her cheeks. But, as you can see in her smiley face picture, she is feeling well. The rash can look more spread out, but commonly grows together into large red, lacy patches.

The 12 year old patient I saw today, was a little less happy. His rash was really itchy. I’ve seen very few Fifth’s rashes that are itchy, but his was pretty bad. I read somewhere that the itching is more common in teens and adults. I don’t promote any particular product, but I like to use Calmoseptine ointment. We applied this to his rash, and he immediately felt better. Do not apply Benadryl (diphenhydramine) cream to large areas of skin. Benadryl cream is absorbed through the skin and there is no way to monitor the dosing, it is not safe. Zyrtec or Benadryl can be taken by mouth to help combat the itchiness. Do not take both Zyrtec and Benadryl at the same time, be sure to follow the instructions on the package insert.

So, when can Parvovirus B19 be a problem? The first thing that comes to any providers mind is pregnancy. Parvovirus B19 can be detrimental to an unborn fetus. It has to do with depletion of the red blood cells (RBCs), leading to fetal anemia and the inability to replenish the lost RBCs to maintain adequate oxygenation, but I won’t get into the sciency stuff. The CDC reports that about 50% of women are immune to Parvovirus B19. If you want to read more about the science, check out CDC or KidsHealth.

What YOU need to know about Fifth Disease:

• Contagious during the fever and URI period.
• NOT contagious with the rash. Can attend school or daycare.
• Incubation period is a few weeks after initial exposure.
• Treatment should focus on comfort measures. Motrin for fever. Creams/oatmeal bath for itching. Zyrtec or Benadryl orally for itching.
• There is no medication to prevent or cure Fifth Disease.
• Pregnancy = Red Flag (see below)

One of the most important pieces of knowledge you can take away from this post is about Fifth Disease and Pregnancy. If your child has Fifth Disease, please think of anyone that you know that may be pregnant, and was in contact with your child during the contagious period. (Think about teachers.) There usually is not a problem, but it is important for a pregnant woman’s obstetrician to be aware of and monitor the exposure appropriately. If the pregnancy is into the 2nd trimester, the blood work is probably already done. For more information about Parvovirus B19 and Pregnancy, check out the CDC’s website.

Erythema infectiosum is one of the easier illness we will encounter on this journey called parenthood. If you have any questions or comments, let me know. If you want to know more about Erythema Infectiosum check out the CDC Parvovirus B19 and Fifth Disease website.

Enjoy the journey, friends! 😉