Yeah, a fifteen-fret uke will have two octaves. The lowest note is middle C. Then the E string (open) is the E above middle C, the A (also open) is the A above middle C, then fifteen frets down you have the second C above middle C. That's two octaves.
Yes, peanuts and peanut butter can aggravate arthritis. I was a peanut butter eater all my life, I am now 58.
If your reaction is worse, you may develop additional symptoms such as a tight throat, hoarse voice, wheezing, coughing, and/or feeling sick to your stomach. Your symptoms may start from within a few minutes to a few hours after eating peanuts or peanut products.