Abstract
Objectives: Musculoskeletal pains are sometimes misdiagnosed in some diseases, like rheumatoid and psoriatic arthritis, erosive OA, etc. Secondary hyperparathyroidism was not considered a differential diagnosis for RA, despite the fact that it can cause arthralgia or arthritis. Also, fibromyalgia is a psychosomatic condition marked by widespread pain and tenderness. Methods: This study included 400 patients attended outpatient clinics of Al-Azhar Faculty of medicine in Egypt, and Elaj Specialized Clinics in Saudi Arabia, who were not fulfilling criteria for RA diagnosis, and not responding to its treatment. Other diseases like psoriatic arthritis and erosive OA were excluded. Criteria for classification of fibromyalgia syndrome were applied to all patients. We did lab tests of RF, ACPA, ESR, CRP, LFT, RFT, vitamin D3, PTH, calcium, phosphorus, and SUA. Radiological imaging modalities for diagnosis or exclusion of suspected diseases were applied. Results: All patients were fulfilling both old and new criteria of fibromyalgia syndrome, and not fulfilling any RA criteria, 18% were seropositive with low RF titers and negative ACPA. All patients had vitamin D3 deficiency or insufficiency. 75% of patients had abnormally high levels of PTH, and had no parathyroid gland pathology. X-rays showed subperiosteal and subchondral resorption of mainly thumbs, subchondral osteopenia of proximal and middle phalanges, mild subperiosteal resorption along the radial aspect of the middle phalanx and mild tuft erosions, besides changes in the carpus closely resembling those of rheumatoid arthritis, of ulnar styloid resorption, radiocarpal and scapho-trapezoid joint arthritis. Of special interest, the presence of tuft spurs-like excrescences.
A Syndrome of Vitamin D3 Deficiency/Fibromyalgia/Hyperparathyroidism Mimicking Rheumatoid Arthritis, a Clinical Prospective Study