A member of the PRP Facebook Support Group asked about the rarity of juvenile onset PRP. My math may be flawed, but consider the following:

(1) Overal incidence rate for "active" PRP: one in 400,000

(2) That equates to 2.5 "active" PRP patients in 1 million

(3) For adult onset (55%): one in 1,375,000

(4) For juvenile onset (45%): 1 in 1,125,000

Based on a US population of 324,493.740 (World Clock), the current "active" PRP population should be: 811 of which 446 would be adult onset and 365.

Bottom line: We are rare, but much more prevalent than unicorns.