Which is correct, 'chickenpox' or 'chicken pox'?

My Merriam-Webster Collegiate Dictionary doesn't even enter chickenpox and allows only chicken pox. My OED, however, does enter it as a hypenated word. None of my style books even addresses this. I had hoped that smallpox would be treated the same, but it isn't. read more

Google uses chicken pox in its search engine and article titles, but then uses chickenpox in its captions. The on-line dictionary enters only chicken pox, while health site articles use chickenpox. I still prefer chicken pox. It seems to me that the disease family is the pox, while small and cow, and chicken are all adjectives. read more

In 2015 chickenpox resulted in 6,400 deaths globally – down from 8,900 in 1990. Death occurs in about 1 per 60,000 cases. Chickenpox was not separated from smallpox until the late 19th century. In 1888 its connection to shingles was determined. The first documented use of the term chicken pox was in 1658. read more

Chickenpox is most contagious from 1 to 2 days before the rash appears until all the blisters are dried and crusted. The best way to prevent the spread of the virus is to get the varicella vaccine. Children who’ve never had chickenpox should get two doses of the vaccine -- the first at 12 to 15 months of age, and the second at 4 to s6 years. read more