What Are Tophi? Gout Lumps

What it means

Tophi (singular: tophus) are lumps made of uric acid crystals. They form when uric acid has been high for a long time, and can appear under the skin around joints, on the fingers, elbows, toes or the edge of the ear. They are often painless but can become inflamed, affect joint movement or, rarely, break through the skin.

The word appears on gout medicine labels and clinic letters because tophi are a sign of more advanced or long-standing gout. Urate-lowering medicines are used to bring uric acid down so that tophi can slowly shrink over time.

Tophi are different from other lumps near joints, such as rheumatoid nodules or osteoarthritis bony swellings. A doctor may use an examination, imaging or a sample to tell them apart.

Where you may see it

• Gout medicine labels under 'Indications' or clinical studies
• Rheumatology clinic letters
• X-ray, ultrasound or dual-energy CT reports