Arizona Anon here. I have a theory the Valley Fever increase is related to Gardasil and the HPV vaccination.
Started looking when a friend's otherwise healthy son came down with it. They don't break the data out well by age group so I can't confirm an increase among adolescents, but they do break out by gender.
Used to be most common in males. Then, long about 2009, the rate in females went higher than the male rate. Few years later, males caught back up again.
Coincides with Gardasil vaccines first given to females, then given to males and females.
Not medical anon, but I did some reading on immune system problems with HPV vaccines when my kids got to the age they'd start pushing it on them.