From the Guidelines
A tophus is a hard lump that forms under your skin due to gout, a type of arthritis caused by too much uric acid in your blood, and it is a sign that your gout is not well-controlled, requiring treatment to lower uric acid levels and prevent further complications 1.
What is a Tophus?
A tophus is a deposit of monosodium urate monohydrate crystals that can form in various tissues, including joints, skin, and bones, as a result of high uric acid levels in the blood. These deposits can cause inflammation, pain, and damage to surrounding tissues.
Causes and Risk Factors
Tophi are a common feature of chronic gout, a condition characterized by recurrent episodes of joint pain and inflammation caused by the deposition of urate crystals in the joints 1. The formation of tophi is often associated with long-standing hyperuricemia, which can be caused by a variety of factors, including genetics, diet, and certain medical conditions.
Symptoms and Diagnosis
Tophi can be diagnosed through physical examination, imaging studies, and laboratory tests. They may appear as firm, chalky deposits under the skin, and can range in size from small to large. While tophi themselves are not usually painful, they can cause pain and discomfort if they become infected or press on surrounding nerves.
Treatment and Management
Treatment of tophi focuses on lowering uric acid levels through medications such as allopurinol or febuxostat, as well as lifestyle changes such as limiting alcohol and purine-rich foods 1. In some cases, surgical removal of large or problematic tophi may be necessary to prevent pain, joint damage, or skin ulceration.
Lifestyle Changes
In addition to medical treatment, lifestyle changes can help manage gout and prevent the formation of tophi. These include:
- Limiting alcohol consumption, especially beer and spirits
- Avoiding sugary drinks and foods rich in fructose
- Eating a diet low in purines, such as meat and seafood
- Increasing consumption of low-fat dairy products and cherries
- Engaging in regular physical activity to reduce excess mortality associated with chronic hyperuricaemia 1
From the FDA Drug Label
A pooled analysis of data from Trial 1 and Trial 2 was performed as pre-specified in the protocols At Month 6, the percentage of patients who achieved a complete response (defined as 100% resolution of at least one target tophus, no new tophi appear and no single tophus showing progression)
- A tophus is a deposit of uric acid crystals that can form in the body, often in people with gout.
- Tophi can appear as lumps under the skin, and can be found in various parts of the body.
- In the context of this study, tophi were assessed using standardized digital photography, image analysis, and a Central Reader blinded to treatment assignment 2.
- The study found that approximately 70% of patients had tophi at baseline.
From the Research
What is a Tophus
- A tophus is a deposit of monosodium urate (MSU) crystals that can form in people with gout, a type of inflammatory arthritis 3, 4, 5.
- Tophi are chronic foreign body granuloma-like structures containing collections of MSU crystals surrounded by inflammatory cells and connective tissue 3.
- They can develop in various parts of the body, including joints, skin, and soft tissues 3, 6.
Characteristics of Tophi
- Tophi are often associated with advanced gout and can impact health-related quality of life 3.
- They can also contribute to the development of structural joint damage and increased mortality risk in people with gout 3.
- Tophi can be a first clinical sign of gout, although this is less common 6.
Treatment and Management
- Effective treatment of tophaceous gout requires long-term urate-lowering therapy, ideally to achieve a serum urate concentration of <5 mg/dL (300 μmol/L) 3, 4, 7.
- The goal of treatment is to lower serum uric acid levels to promote the dissolution of MSU crystals and reduce the size of tophi 3, 7.
- Lifestyle modifications, such as weight loss, avoidance of alcohol and purine-rich foods, and diuretics, can also help manage gout and prevent the formation of tophi 4, 5.