Health condition
Sweet syndrome
Sweet syndrome (acute febrile neutrophilic dermatosis) causes the sudden appearance of tender, juicy red plaques with fever and raised inflammatory markers - it responds rapidly to corticosteroids but always warrants a search for an underlying cause.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Sudden crops of tender, raised, red-to-violet plaques on the face, neck and arms, often with fever
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Skin biopsy shows a dense infiltrate of neutrophils without vasculitis, confirming the diagnosis
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It may follow an infection, accompany inflammatory disease or a new medicine, or - in a minority - signal an underlying blood disorder
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Corticosteroids usually settle it within days, but recurrence is common if the trigger persists
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
The rash of Sweet syndrome looks almost blistered - plaques so oedematous they appear fluid-filled - and it typically arrives abruptly alongside fever, fatigue and joint aches. Most cases are 'classical', following a respiratory or gut infection, but the syndrome can also be triggered by drugs or associated with malignancy, particularly acute myeloid leukaemia and myelodysplasia.
Diagnosis and treatment routes
A dermatologist confirms the picture with a punch biopsy and arranges blood tests - full blood count and film as a minimum - to look for an underlying haematological cause, with further investigation guided by the findings. Prednisolone produces a strikingly fast response; colchicine, dapsone or potassium iodide are alternatives for people who relapse when steroids are withdrawn. In much of the UK, a routine NHS referral to the relevant specialist clinic can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant dermatologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Sweet syndrome.
Quick, plain-English answers to what people ask us most.
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Can you explain what sweet syndrome is?
Sweet syndrome is a medical condition that can affect people differently depending on severity, underlying cause and overall health. A clinician can confirm the diagnosis and explain what it means specifically for you.
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What causes sweet syndrome?
Causes vary and can include genetic, environmental, lifestyle and other health-related factors, and in some people no single clear cause is found. Your clinician can help identify anything relevant to your own case.
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What does sweet syndrome look like or feel like?
Symptoms vary between individuals and depend on which body systems are affected and how significant the underlying problem is. Keeping track of what you notice, and when, helps your clinician assess it accurately.
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How worried should I be about sweet syndrome?
Severity varies from mild and self-limiting to more significant, depending on the underlying cause and how it's managed. A clinical assessment is the best way to understand what it means in your specific situation.
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Is sweet syndrome hereditary or genetic?
This depends on the specific condition — some cases have a genetic or familial component, while others are linked more to environmental, lifestyle or other health factors. If you have a relevant family history, it's worth mentioning to your clinician.
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Is there a cure for sweet syndrome?
Many cases can be effectively treated or managed, and prevention strategies exist for some causes, though this depends on the specific underlying reason in your case. Your clinician can explain what's realistic for you.
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How is sweet syndrome treated?
Treatment is tailored to the underlying cause and severity, and can range from simple lifestyle or self-management measures to medical or specialist intervention.
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What is the long-term outlook for sweet syndrome?
This varies depending on the underlying cause, how early it's identified, and how well it responds to treatment — your clinician can give a more specific expectation once assessed.
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When should specialist referral be considered for sweet syndrome?
Specialist referral is worth considering if symptoms persist, are getting worse, or aren't responding to initial treatment — your GP can help decide the right pathway and urgency.
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When should I see a doctor about sweet syndrome, and how quickly can I be seen privately?
See a doctor if symptoms are persistent, worsening, or affecting your daily life — earlier assessment generally leads to better management. NHS routine referrals for this kind of concern often take 20–45 weeks or longer depending on the area, while a private consultant can typically see you within about 2 weeks, with faster access to scans and specialist opinion.