Fifth Disease?!Ā What happened to Fourth Disease?!
Today Dr. B is going to teach you some old, outdated medicine that will only help you at some sort of medical trivia event.Ā Good times!Ā As you can probably guess, if its called Fifth disease there must be first through fourth diseases, right?!Ā Well there used to be.Ā The list was based on the most common causes of infectious rashes in kids.Ā Iām not sure when the list was in wide use but it was essentially obsolete by the 90s.
FIRST DISEASEĀ - Measles.Ā Thatās easy.
SECOND DISEASE - Scarlet Fever.Ā Another easy one.
THIRD DISEASE - Rubella.Ā Seems pretty easy.
FOURTH DISEASE - This is where it goes off the rails.Ā Weāll finish the list and circle back.
FIFTH DISEASE - Parvovirus B19, a.k.a. Erythema Infectiosum
SIXTH DISEASE - Roseola Infantum or Erythema Subitum.Ā Caused by human herpes virus 6B and 7.
So letās go back.Ā What the hell is Fourth Disease?Ā When the list was in widespread use, Fourth Disease referred to Filatow-Dukesā Disease.Ā Originally described by Clement Dukes in 1900, there is a debate in modern medicine as to what exactly he was talking about.Ā Some folks think that it refers to Staph Scalded Skin Syndrome, also known as Ritterās Disease.Ā Other folks, however, believe that Filatow-Dukesā Disease is actually people misdiagnosing scarlet fever and therefore doesnāt really exist as its own entity.Ā By the late 60s-early 70s folks were already questioning Fourth Disease with a 1979 article in The American Journal of Disease in Children publishing an article linking it to epidermolytic toxin-producing Staphylococcus.
Despite all this, occasional outbreaks of mysterious rashes in children often raise the question,Ā āIs this Filatow-Dukesā?ā and occasionally papers show up in journals positing another etiology which would reestablish it as a credible diagnosis.
TL;DR, Fourth disease was a crock of shit so the whole numbered rashes thing fell apart like a house of cards.Ā Fifth Disease just had a nice ring to it so the name stuck.
Welp, got my learninā for the day, I get to go home now.

















