The other day, while explaining to a mother that her 5-year-old son was about to receive a chickenpox vaccine, the little boy asked me:

 “Why do they call it ‘chickenpox’?”


Silence. My mind draws a blank on this particular subject.

“Uh… I’ve got nothing. Let me do some research and post the answer on The PediaBlog this week, so be sure to read it,” I told him.

Let’s start with the “pox” first. According to the Collins English Dictionary and

pox (pɒks)


1. (Pathology) any disease characterized by the formation of pustules on the skin that often leave pockmarks when healed
2. (Pathology) the pox an informal name for syphilis
3. a pox on someone (interjection) archaic an expression of intense disgust or aversion for someone


We’ll go with number one. Chickenpox (varicella), its bovine counterpart, cowpox (vaccinia), and its more severe cousin, smallpox (variola), result in ugly-looking pustules on the skin which, when they resolve, leave small, pitting indentations or scars called pockmarks. (And no, I don’t know why it’s “pox” and not “pocks”!)

Where does the “chicken” part of chickenpox come from? Ah, now things get interesting. has this to say about it:

The name chickenpox has been around for centuries, and there are a number of theories as to how it got its name. One is that it’s from the blisters that are seen with the illness. These red spots — which are about 1/5 inch to 2/5 inch (5mm to 10mm) wide — were once thought to look like chickpeas (garbanzo beans).

Another theory is that the rash of chickenpox looks like the peck marks caused by a chicken. But, in case you were wondering, chickenpox can’t be caught from a chicken!


A reader at Quora chimes in with her 2 cents:

the term reflects a corruption of the Old English word, “giccin”, which meant “itching”


Perhaps the best answer comes from The Straight Dope:

It is surprising how many physicians and others who are knowledgeable about childhood diseases don’t know the answer to this question. Here’s an answer from, which has a pretty good medical dictionary:

“Chickenpox (varicella): A highly infectious viral disease, chickenpox is known medically (and in many countries) as varicella. Chickenpox has nothing to do with chicken. The name was meant to distinguish this “weak” form of the pox from smallpox (chicken being used, as in chickenhearted, to mean weak or timid). The “pox” of chickenpox is no major matter unless infected (through scratching) or occurring in an immunodeficient person.”

Okay, but then shouldn’t smallpox be called “Big Frigging Pox” or something instead?


There you go, young man! Now we all know why it’s called “chickenpox”!


(Google Images)