This is a case of a 39-year-old male, a known patient with type 2 diabetes mellitus on metformin and gliclazide for 2 years, with optimal glycemic control, presented with a history of fever for 3 days and an abrupt onset of pain and swelling involving both the dorsum of the hands and wrist joints symmetrically. He also noticed pain and swelling in his left knee for 1 week. He was free from back pain, constitutional symptoms, and ankle swelling. He had good appetite and there was no significant history of weight loss. He denied any history of recurrent fever in the past, rashes, chronic cough, diarrhea, burning micturition, features of urinary outflow obstruction, urethral discharge, or sexual promiscuity. He had no family history of rheumatological disease or malignancies. He was a non-smoker and non-alcoholic.
On examination, he was a well-built male and his vitals were stable with a blood pressure of 120/80 mmHg, a heart rate of 86 beats per minute, and a temperature of 37 degrees. He had tender pitting edema involving the dorsum of both hands symmetrically. An examination of the joints showed tenderness, warmth, and swelling, suggestive of synovitis with restricted movements in wrists, bilateral metacarpophalangeal (MCP) joint, proximal interphalangeal (PIP) joint, and the left knee. He had no ankle edema, lymphadenopathy, tenderness over the lower back and sacroiliac joints, and features of enthesitis. Rest of the clinical examinations including cardiovascular, respiratory, abdominal, and neurological examinations were unremarkable (initial presentation of the patient is shown in Figure 1).
At this point, RA, seronegative spondyloarthropathy, reactive arthritis, and arthritis related to the chronic infections such as tuberculosis, polymyalgia rheumatica (PMR), and RS3PE were considered as differential diagnosis. The initial investigations were performed to confirm the diagnosis.
His salient clinical and laboratory features are summarized in Table 1. Sonographic examination of both hands and wrists showed features of tenosynovitis with soft tissue edema and joint effusion. X-rays of the hands did not show any erosions and x-rays of the lambosacral spine and sacroiliac joints were normal.
Further investigations revealed a negative RF (<20 IU/mL), anti-nuclear antibodies (ANAs), and anti-neutrophil cytoplasmic antibodies (ANCAs). Anti-cyclic citrullinated peptide antibody (anti-CCP Ab) level was negative. Venereal disease laboratory (VDRL) test and retroviral studies were also negative. Screening for tuberculosis was performed to exclude the possibility of Poncet's disease with three sputum direct smears, chest x-ray was normal, and tuberculin skin test was negative. At this point, the diagnosis of bilateral RS3PE was made.
To evaluate the possible underlying cause and exclude the possible malignancies, other investigations including serum amylase, lactate dehydrogenase (LDH), blood cultures, antistreptolysin O titer (ASOT), thyroid-stimulating hormone (TSH), free T4, and serum uric acid were performed, which were unremarkable. Ultrasonography of the abdomen and pelvis revealed normal size and architecture of the liver, spleen and kidneys; there were no lymphadenopathy or tumors. Blood picture was obtained to exclude the possibility of hematological malignancies, which was normal.
He was treated with both etoricoxib, a selective cyclooxygenase 2 (COX-2) inhibitor, and low-dose oral prednisolone. Initially, he was given 15 mg of prednisolone, which was continued for 2 weeks and then tailed off over the next 2 weeks. He showed a marked improvement clinically and his inflammatory markers returned to normal levels in 4 weeks. He became free of symptoms at 2 months and maintained the remission for 6 months of follow-up.