The Four-Year-Old was diagnosed with Fifth Disease last week. Fifth Disease is one of those deliciously mild childhood illnesses that nearly all of us get at one point or another, that are most contagious before any symptoms appear, and that clear up (in most cases) on their own. (The exception is for pregnant women, who need to talk to their OB if they are exposed to Fifth Disease during their pregnancy.)

In my daughter’s case, the symptoms appeared as crankiness two weekends ago, and a rash that appeared on her cheeks last Monday and spread to her arms and legs last Wednesday. That’s it. By the time the rash clued me in to the fact that she was sick, she was no longer contagious and back to feeling great. (Loyal readers will be glad to know that the Monday Night Sproing Cat Ballet Recital was held as planned.)

But in all the shuttling to and from the doctor last week, my daughter had plenty of time to ask questions, including “Why is it called Fifth Disease?”

If Fifth Disease doesn’t win the prize for Most Literal Name in Medicine outright, it should at least be given an Honorable Mention. Turns out Fifth Disease earned its name because it was the fifth in a series of very similar-looking rashes to be identified by doctors. The rest of the series includes measles (Rubeola), scarlet fever (Scarlatina), German measles (3-day measles, rubella) and Dukes’ disease.

Thank goodness The Four-Year-Old didn’t get any of those.