FEVER OF UNKNOWN ORIGIN (FUO)

 Basic information

description

Fever of unknown origin is a diagnosis given in cases where a person has had a fever (off and on) for at least 3 weeks, and no cause has been found after a basic medical evaluation.

FREQUENT SIGNS & SYMPTOMS

• Temperature above 101°F (38.3°C) on several occasions over a 3-week period.
• Muscle aches, chills, and headaches may occur in some cases.

causes

• In infants and children:
  • Infections.
  • Collagen or autoimmune diseases.
  • Tumors and cancer, especially leukemia.
• In adults:
  • Infections.
  • Collagen or autoimmune diseases.
  • Tumors and cancer, especially kidney cancer, leukemia, and lymphoma.
  • Self-induced (in some emotionally unstable persons).
  • Drugs can cause a fever as an adverse reaction.

risk increases with

• Weak immune system due to illness or drugs.
• Chemical or environmental exposure to polluted water or air.
• Travel in areas with unsanitary conditions.
• Exposure to others with infectious diseases.
• Elderly persons.
• Drug abuse.

PREVENTIVE MEASURES

There are no specific preventive measures.

expected outcomes

Recovery without any treatment occurs in some cases. In other cases, the outcome depends on successful diagnosis and treatment of the underlying disorder.

possible complications

Depends on the underlying condition causing the fever.

 diagnosis & treatment

general measures

• Your health care provider will do a physical exam and ask about your symptoms and activities. Because a fever may be the first evidence of a serious condition (in its early stages), careful medical testing may be done. This may include blood studies and a urine culture, x-rays of the chest, CT scan, an ultrasound, echocardiogram (heart function test), thyroid studies, liver function tests, an HIV antibody test, and others.
• Hospital care may be recommended for elderly patients, patients with weak immune systems, and those with a serious chronic illness.
• When at home, keep a daily temperature chart. Rectal temperatures are most accurate.
• Treatment will depend on the underlying cause that is found.

medications

• Acetaminophen or ibuprofen may be prescribed, to lower the fever.
• Until the cause is found, other prescription drugs may be withheld to avoid masking symptoms of the underlying disorder.
• In certain patients, antibiotics, steroids, or other drugs may be prescribed prior to a specific diagnosis.

activity

Get extra rest while you have a fever.

diet

No special diet. Drink extra fluids while you have a fever.

 notify our office if

• You or a family member has an unexplained fever that lasts longer than 24 hours.
• New symptoms develop. They may provide a clue about the underlying cause of the fever.

Special Notes: