Sweet syndrome, also called acute febrile neutrophilic dermatosis, is an uncommon skin condition. It causes fever and a painful skin rash that appears mostly on the arms, face and neck.
The cause of Sweet syndrome isn't known, but it's sometimes triggered by an infection, illness or medicine. It can also occur with some types of cancer.
The most common treatment for Sweet syndrome is corticosteroid pills, such as prednisone. Signs and symptoms may go away after just a few days of treatment but can come back again.
Symptoms of Sweet syndrome include:
- Painful small inflamed bumps on your arms, face, neck or back
- Bumps that grow quickly in size, spreading into painful clusters up to an inch (2.5 centimeters) in diameter
When to see a doctor
See your health care provider if you develop a painful rash that quickly grows in size.
In most cases, the cause of Sweet syndrome isn't known. The condition is sometimes related to blood cancers, such as leukemia, or solid tumors, such as breast or colon cancer. It might also occur as a reaction to medicine — most commonly a type of drug that boosts production of white blood cells.
Sweet syndrome is uncommon, but certain factors increase your risk, including:
- Sex. Women are more likely to have Sweet syndrome than are men.
- Age. The condition mainly affects people between the ages of 30 and 60.
- Cancer. Sweet syndrome is sometimes associated with cancer, most often leukemia but also breast or colon cancer.
- Other health problems. Sweet syndrome may follow an upper respiratory infection. And many people report having flu-like symptoms before the rash appears. Sweet syndrome can also be related to inflammatory bowel disease.
- Pregnancy. Some women develop Sweet syndrome while pregnant.
- Drug sensitivity. Sweet syndrome may result from a sensitivity to certain medicines, including azathioprine (Azasan, Imuran), granulocyte colony-stimulating factor, antibiotics and some nonsteroidal anti-inflammatory drugs.
This condition does not appear to have a racial predilection.
There is a risk of the skin sores becoming infected. Follow your health care provider's advice on caring for the affected skin.
In cases where Sweet syndrome is related to cancer, the sores may be the first sign of cancer either appearing or recurring.
A doctor who specializes in skin conditions (dermatologist) might be able to diagnose Sweet syndrome simply by looking at your skin. But you may need testing before your doctor can make a definite diagnosis. Tests that are useful in assessing people for Sweet syndrome include:
- Blood tests. A sample of your blood may be sent to a laboratory where it's checked for too many white blood cells and certain blood disorders.
- Skin biopsy. Your health care provider removes a small piece of affected tissue for examination under a microscope. It's analyzed to see whether it has the traits of Sweet syndrome.
Sweet syndrome might go away without treatment. But medicine can speed the process. The most common medicines used for this condition are corticosteroids:
- Pills. Oral corticosteroids, such as prednisone, work very well but will affect your entire body. Unless you only have a few lesions, you'll likely need to take oral corticosteroids. Long-term use can cause side effects, such as weight gain, insomnia and weakened bones.
- Creams or ointments. These products usually affect just the skin where they're applied. They can cause thinning skin.
- Injections. Another option is to inject a small amount of corticosteroid into each sore. This is likely not a good option for people who have many sores.
You'll need to take the drug for several weeks to prevent relapse. If long-term corticosteroid use is a problem for you, ask your health care provider about other prescription medicines that might help. Some common alternatives to corticosteroids are:
- Potassium iodide
- Colchicine (Colcrys, Mitigare)
Preparing for an appointment
Your health care provider is likely to refer you to a dermatologist for diagnosis and treatment of Sweet syndrome. Here's some information to help you get ready for your appointment.
What you can do
Before your appointment, make a list of:
- Symptoms you've been having and for how long, including those that seem unrelated to your rash
- All medicines, vitamins and supplements you take, including doses
- Questions to ask your health care provider
If you have symptoms of Sweet syndrome, questions you may want to ask include:
- What might be causing my rash?
- What tests do I need to confirm the diagnosis?
- Is this condition temporary or long-lasting?
- What treatment options are available, and which do you recommend for me?
- What side effects can I expect from treatment?
- Is there a generic alternative to the medicine you're prescribing me?
- What if I just wait to see if my symptoms go away on their own?
What to expect from your doctor
Your health care provider is likely to ask you a number of questions, such as:
- When did your skin symptoms start?
- Did they come on suddenly or gradually?
- What did the rash look like when it first appeared?
- Is the rash painful?
- Does anything make your symptoms better?
- Does anything make your symptoms worse?
- Were you sick before the rash started?
- What medical problems have you had?
- Do you have other symptoms that started about the same time?
- What medicines do you take?
- Did the skin sores start in the days or weeks after you started a new medicine?