Investigating Gout

Investigouting

Welcome back Rheumatology Fans,

I was reminded of Gout testing the other day and there are some misunderstandings so lets get into some detail!

Contents

• Synovial Fluid Analysis

• Laboratory Studies (Bloods)

• Imaging

Synovial Fluid Analysis

Simply, get a whacking great needle, jam it in the joint and take out some fluid. This is the gold standard investigation for gout.

In gout, synovial fluid is usually yellow and cloudy, it contains crystals (made of uric acid) and white blood cells (predominantly neutrophils). You need “compensated polarised light microscopy” to visualise the important components of the synovial fluid.

Synovial Fluid Analysis presents some logistical issues to most of us in the Musculoskeletal space.

• Not trained to collect the sample

• No access to microscopy and not sure what to look for anyway

• I DARE you to suggest to someone with acute gout that you are about to stick a needle in their joint…

Mostly Synovial Fluid analysis is going to be done in A&E or Orthopaedics, this will mostly be in cases where other differential diagnoses are suspected, usually Septic Arthritis or Fracture.

The logistical challenge added to tbe fact that it is seriously uncomfortable for the patient means that while this is gold standard it is not usually the first line. It is usually not necessary to analyse the synovial fluid, good clinical reasoning and the other investigations will often be sufficient.