Isolated adrenocorticotropic hormone deficiency presenting with arthritis: A case report.

This article presents a case report of isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) manifesting as polyarticular arthritis, a rare presentation that initially evaded diagnosis due to lack of typical connective tissue disease markers. The 62-year-old patient exhibited joint pain, muscle stiffness, and systemic symptoms without autoantibody positivity or imaging findings characteristic of rheumatoid arthritis, and was ultimately diagnosed with IAD following an adrenal crisis and comprehensive endocrine testing. Corticosteroid replacement therapy resolved both the musculoskeletal and systemic symptoms, highlighting the importance of considering endocrine disorders like IAD in the differential diagnosis of unexplained arthritis accompanied by systemic features. The report also discusses potential mechanisms linking ACTH deficiency to arthritis, including loss of endogenous cortisol’s anti-inflammatory effects and direct immunomodulatory roles of ACTH.