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Sweet's syndrome


What are the aims of this leaflet?

This leaflet has been written to help you understand more about Sweet’s syndrome. It tells you what it is, what causes it and where you can find out more about it.

What is Sweet’s Syndrome?

Sweet’s syndrome (also known as acute febrile neutrophilic dermatosis) is an uncommon skin disorder characterised by a fever and the appearance of tender red lumps on the skin. It is a reactive condition with a number of potential triggers. It is not contagious and cannot be transferred from one person to another.

What causes Sweet’s Syndrome?

In 50% of those affected it is not possible to identify a cause. Examples of causes include upper respiratory tract infections, inflammatory bowel disease, rheumatoid arthritis and pregnancy. Sweet’s syndrome can also be caused by some medications and may be a sign of an underlying blood disorder or an internal cancer, but it is important to know that having Sweet’s syndrome does not mean that you definitely have one of these diseases.Sweet’s syndrome   may improve or resolve with treatment of the underlying condition. 

Is Sweet’s syndrome hereditary?

It is very unusual for Sweet’s syndrome to affect more than one family member. In some of those cases a genetic link has been shown, but it is not normally a hereditary condition.

What does Sweet’s syndrome of the skin look like?

The most common skin changes in Sweet’s syndrome are raised red, pink or purplish tender skin lumps. These can be small (known as papules, which can be about 5-10 mm) or larger (known as nodules) and can join together to form bigger areas (known as plaques). They can be single or multiple and can appear anywhere on the skin although the arms, face and neck are affected most often. Sometimes blisters or pustules can be seen and the rash may appear at the site of an injury to the skin.

What are the symptoms of Sweet’s syndrome?

Sweet’s syndrome may cause some or all of the following symptoms arising together over a period of hours or a few days:

  • a rash (described above)

  • tiredness, lack of energy and feeling unwell

  • high fever (temperature)

  • aching joints and muscles

  • mouth ulcers

  • sore eyes

How will Sweet’s syndrome be diagnosed?

Tests that are useful in Sweet’s syndrome include:

  1. A biopsy. This is the most important test. A sample is taken from a part of the skin involved by the Sweet’s syndrome and then examined under the microscope.

  2. Blood tests such as a high white blood cell count can help make a diagnosis of Sweet’s syndrome.

  3. Your doctor may recommend other blood tests or x-rays to look for a cause of the Sweet’s syndrome.

  4. If a medication is thought to be responsible, your doctor may recommend stopping it for a while.

Can Sweet’s syndrome be treated?

Treatment is available for Sweet’s syndrome and it can improve quite quickly. Treatments can be divided into local and systemic options.

  1. Local applications to the skin (topical treatments)

    • Strong steroid creams may help, especially with smaller lumps, and may help reduce the tenderness. Occasionally, steroid injections can be used for very swollen or painful lumps.

  2. Systemic treatments

    • Steroid tablets (e.g. prednisolone) can be a very effective treatment for Sweet’s syndrome. They are usually given at a higher dose to start with and then a lower dose may be given for a number of weeks to prevent the rash coming back.

    • Anti-inflammatory agents. Oral therapy with the medications dapsone, colchicine, potassium iodide or indomethacin can also be very effective and may be preferred by your doctor if you cannot take steroid tablets because of other medical problems.

    • Immunosuppressive agents (e.g. ciclosporin) reduce the action of the body’s own defence system (the immune system) and can also be very useful for treating Sweet’s syndrome.

These medications can have certain side effects and you may be advised to have regular blood tests if you are prescribed one of these treatments.

If an underlying medical problem is found, treating this itself may lead to an improvement in the Sweet’s syndrome. Recurrences are common, and treatment may need to be reintroduced till recurrences cease. In rare cases, the condition persists indefinitely. 

Where can I get more information about Sweet’s syndrome?

Web links to detailed leaflets and further information:

For details of source materials used please contact the Clinical Standards Unit (

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists; its contents, however, may occasionally differ from the advice given to you by your doctor.

This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel





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