Cat scratch fever is a bacterial infection you can get from being scratched or bitten by a cat or kitten, or sometimes a dog. This usually goes away without treatment, but can become a potentially serious condition that requires care from your doctor.


  • The bacteria that causes cat scratch fever is found in fleas and is passed to cats through flea bites, then to humans through a cat scratch or bite.
  • Children under age ten are most often affected because they are most often the victims of a cat scratch or bite.

Risk Factors

The following factors increase your chances of getting cat scratch fever:

  • A recent bite or scratch from a cat or kitten.
  • A weakened immune system, which increases your chances of getting serious complications of the disease. People with weakened immune systems include babies and elderly people, and those with HIV/AIDS , organ transplants, or cancer .


Swollen Lymph Nodes

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  • A crusting sore or blister that develops over the site of a cat scratch or bite
  • Swollen, painful lymph nodes
  • Low-grade fever
  • Flu-like symptoms such as weakness, nausea, chills, loss of appetite, and headache.
  • If you do not start to get well within in a few days, you may develop complications such as a very high fever or pneumonia. Severe cases have caused infections of the brain ( encephalitis ), hepatitis, and even death.


Your doctor will ask about your symptoms and medical history, and perform a physical exam. If you remember that you were bitten or scratched by a cat, your doctor will probably be able to diagnose the disease based on the fact that you were bitten or scratched, then got painful, swollen lymph nodes. Tests may include:

  • A blood test, especially if the diagnosis is not clear from the exam and medical history alone.


Talk with your doctor about the best treatment plan for you. Treatment options include:

  • Rest and non-prescription pain relievers, such as acetaminophen.
  • Lymph node drainage—If a lymph node is very swollen or very painful, your doctor may drain it to help it heal and to relieve pain. To do this, your doctor will put a hypodermic needle into the swollen node. Fluid inside the node will then drain out through the needle.
  • Antibiotics—Cat-scratch fever usually clears up without treatment. If lymph nodes stay painful and swollen for more than two or three weeks, or if you get very ill, you may need antibiotic treatment. Antibiotics may also be prescribed for those with HIV infection or other immunocompromising diseases.


To prevent cat scratch fever, take the following steps:

  • The best prevention against cat scratch disease is to keep from getting scratched or bitten by a cat or a dog.
  • If you do get bitten or scratched, wash immediately with antiseptic soap and hot water.
  • Keep your pets free of fleas.