Chronic Joint Pain in a Young Adult With Cystic Fibrosis.

A 25-year-old male with end-stage cystic fibrosis (CF) with genotype F508del/F508del presented to the clinic complaining of bilateral knee and ankle pain. He had severe lung disease (forced expiratory volume 1 {FEV1} 19% of predicted), chronic colonization with achromobacter, malnutrition, and CF-related diabetes. On physical examination, he was found to have bilateral knee swelling as well as pain on flexion and extension of the wrists and ankles without erythema or warmth. He was empirically started on prednisone and tramadol; however, at a three-month follow-up visit, he remained symptomatic. He was sent for a whole-body bone scan, which was consistent with hypertrophic pulmonary osteoarthropathy (HPOA). He was started on highly effective modulator therapy with elexacaftor/tezacaftor/ivacaftor and symptoms spontaneously resolved without further intervention.