Diagnosis of gout
Early diagnosis of gout is essential to avoid the chronic case, permanent damage of joints, and kidney affection. Early diagnosis also enables the doctor to differentiate between gout and other diseases that cause similar symptoms, such as septic arthritis, which is a medical emergency.
The diagnosis of gout begins with your description of the pain. If your description corresponds to the classic acute gout pain, your doctor will suspect gout. He will ask you about the previous causes and risk factors to see if the gout is secondary and to consider this in the treatment. The history may be enough for diagnosis, and the doctor may begin the treatment depending on the diagnosis with history only. But in some cases, the doctor may need further investigation to confirm his diagnosis and to exclude other conditions, such as septic (infectious) arthritis. These investigations include:
- The uric acid level in blood: In gout, it will be >7mg/dl in males and >6mg/dl in females. The average uric acid level range is (2.5 – 7) mg%. Hyperuricemia is the hallmark of gout, but it can’t exclude or confirm gout alone.
- Arthrocentesis (Synovial fluid aspiration and examination): It is the most definitive diagnostic tool. A trained physician will remove some synovial fluid from the inflamed joint and examine it under a polarized light microscope. In gout, synovial fluid will show:
- monosodium urate crystals (needle-shaped and strongly negative birefringent crystals)
- white blood cells (20000-50000 cell/mm3)
→ Arthrocentesis differentiates gout from other similar conditions, such as pseudogout, septic arthritis, and rheumatic arthritis.
- Imaging (x-ray): It may be normal in acute and early cases, but it is useful in chronic gout. In chronic gout, X-ray will show the erosions and deformity around the affected joint.
- Blood picture: Blood examination will reveal:
- Leukocytosis (increased white blood cells)
- High inflammation markers, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)
- Kidney function tests and renal imaging: The doctor may want to see if there is monosodium urate deposition in the kidney to consider this in the treatment.
- The uric acid level in 24hour-urine: This test will be useful to detect if the problem is an overproduction or under excretion of uric acid, and this will guide the treatment. If the problem is overproduction, the uric acid will increase in 24hour-urine. But, if the problem is under excretion, uric acid will decrease in 24hour-urine. The average range of uric acid levels in 24hour urine is (250 – 750) mg.
After confirmation of gout, the doctor will start the treatment immediately to avoid progression to the chronic stage that may cause permanent joint damage and deformity, kidney affection, and tophi formation.
⇒ Now, let’s discuss the treatment of gout
