The association between refractory plantar fasciitis and insertional Achilles tendinopathy and peripheral spondyloarthritis: a report of human leukocyte antigen B-27 investigation and treatment outcome.

Among the patients with "refractory" plantar fasciitis and insertional Achilles tendinopathy, 17.5% were diagnosed with peripheral spondyloarthritis. Patients diagnosed with peripheral spondyloarthritis had a higher proportion of men and relatively younger mean age compared to those without the diagnosis. Approximately 70% of these patients achieved symptom improvement in foot and ankle joints by taking conventional synthetic DMARDs, TNF-α inhibitors, or both appropriate for spondyloarthritis.