Hypertrophic osteoarthropathy is divided into primary and secondary forms. Pachydermoperiostosis (PDP), the primary form, accounts for 5% of all cases of hypertrophic osteoarthropathy. Secondary hypertrophic osteoarthropathy, also called pulmonary hypertrophic osteoarthropathy, is associated with underlying cardiopulmonary diseases and malignancies.
Pachydermoperiostosis or primary hypertropic osteoarthropathy is a rare hereditary disorder that was first described in 1868. It is characterized by digital clubbing, pachydermia (thickening of the facial skin and/or scalp), and periostosis (swelling of periarticular tissue and subperiosteal new bone formation). Pachydermoperiostosis or primary hypertropic osteoarthropathy is associated with pain, polyarthritis, cutis verticis gyrata, seborrhea, eyelid ptosis,and hyperhidrosis. Touraine et al described 3 forms of pachydermoperiostosis or primary hypertropic osteoarthropathy: (1) a complete form with pachydermia and periostitis, (2) an incomplete form with evidence of bone abnormalities but lacking pachydermia, and (3) a forme fruste with prominent pachydermia and minimal-to-absent skeletal changes.
I am the second person in the UK on medical record to have level 1, ie the whole shebang.