I did an inter-related "Camptodactyly ... arthritis onset ... treatmen"t search and came up with medicinal paraffin baths and acupuncture as recommended treatments. The hot wax I found messy & a bore although effective--I've got arthritis in both hands. The articles didn't mention acupressure, but it might be worth investigating.
My regular acupuncture procedures have all but eliminated my arthritis, in my hands and elsewhere, over the years of treatment.