Acute febrile neutrophilic dermatosis


Acute febrile neutrophilic dermatosis is a rare inflammatory skin disorder characterized by a fever and a painful rash on the face, neck, arms, legs, and trunk. It is commonly known as the Sweet syndrome.

Sweet syndrome is classified into three categories: classical, malignancy-associated, and drug-induced. A classical sweet syndrome means that the disorder may be associated with other medical conditions such as respiratory infections, gastrointestinal infections, or pregnancy. Malignancy-associated refers to the appearance of Sweet syndrome together with specific kinds of cancer such as acute myeloid leukemia. A drug-induced Sweet syndrome is a reaction to taking certain drugs including granulocyte colony-stimulating factor (G-CSF), NSAIDS, and antibiotics, such as bactrim.

Corticosteroid medications are the most common method of treatment for Sweet syndrome. Signs and symptoms may disappear following treatment. However, there is a chance of recurrence if the underlying cause of Sweet syndrome is left unresolved.


Sweet syndrome can affect anyone. The symptoms may appear suddenly. They could last for weeks, months, or longer depending on the cause. The symptoms may include:

  • Fever
  • Painful bump or pus-filled blisters on the face, neck, arms, back, or legs
  • Rapidly expanding bumps, clusters up to an inch in diameter
  • Lesions of the skin and mouth (sores or tumors)
  • Discoloration of the skin
  • Pain in the muscles and joints, headaches, and exhaustion
  • A general sense of being ill

It is recommended to consult a doctor immediately if a rash is rapidly growing in size or symptoms are progressing.


The exact cause of Sweet syndrome is unknown. It may develop as a side effect of drug, most commonly a treatment that increases the production of white blood cells. It can be also associated with blood cancers or solid tumors, such as breast cancer or colon cancer.

Risk factors

Several factors may affect one’s risk of getting Sweet syndrome, such as:

  • Sex: This condition affects more women than men.
  • Age: People between the ages of 30 and 60 are more susceptible of getting this disease.
  • Cancer: People who have cancer such leukemia, breast and colon cancer are at a higher risk of developing Sweet syndrome.
  • Other medical conditions: Sweet syndrome is sometimes associated with inflammatory bowel disease. It may also occur due to respiratory infections. In most cases, the rash occurs after experiencing flu-like symptoms.
  • Pregnancy: Pregnancy can trigger Sweet syndrome.
  • Drug sensitivity: Several drugs can induce Sweet syndrome such as antibiotics, azathioprine, NSAIDS and granulocyte colony-stimulating factor (G-CSF), which stimulates the body to make neutrophils, a type of immune system cell.

No studies have shown that ethnicity affects one’s risk of developing Sweet syndrome.