Cat scratch disease
Cat scratch disease is an infection with Bartonella bacteria that is believed to be transmitted by cat scratches and bites.
Causes of Cat scratch disease
Cat scratch disease is caused by Bartonella henselae. The disease is spread through contact with an infected cat (a bite or scratch). It also can be spread through contact with cat saliva on broken skin or mucosal surfaces like those in the nose, mouth, and eyes.
Cat scratch disease Symptoms
A person who has had contact with an infected cat may show common symptoms, including:
- Bump (papule) or blister (pustule) at site of injury (usually the first sign)
- Fever (in some people)
- Lymph node swelling (lymphadenopathy) near the site of the scratch or bite
- Overall discomfort (malaise)
Less common symptoms may include:
- Loss of appetite
- Sore throat
- Weight loss
Tests and Exams
If you have swollen lymph nodes and a scratch or bite from a cat, your health care provider may suspect cat scratch disease.
A physical examination may also reveal an enlarged spleen.
Occasionally, an infected lymph node may form a tunnel (fistula) through the skin and drain (leak fluid).
This disease is often not found because it is hard to diagnose. The Bartonella henselae IFA blood test is an accurate way to detect the infection caused by these bacteria. The results of this test must be considered along with other information from your medical history, lab tests, or biopsy.
A lymph node biopsy may also be done to look for other causes of swollen glands.
Treatment of Cat scratch disease
Generally, cat scratch disease is not serious. Medical treatment may not be needed. In some cases, treatment with antibiotics such as azithromycin can be helpful. Other antibiotics may be used, including clarithromycin, rifampin, trimethoprim-sulfamethoxazole, or ciprofloxacin.
In AIDS patients and other people who have a weakened immune system, cat scratch disease is more serious. Treatment with antibiotics is recommended.
Children who have a normal immune system should recover fully without treatment. In people with a suppressed immune system, treatment with antibiotics usually leads to recovery.
Complications may include:
- Parinaud's syndrome (granulomatous conjunctivitis with adenopathy)
When to Contact a Health Professional
Call your health care provider if you have enlarged lymph nodes and you have been exposed to a cat.
Prevention of Cat scratch disease
Avoid contact with cats to prevent the disease. If this is not possible, wash your hands thoroughly after playing with a cat, avoid scratches and bites, and avoid cat saliva to reduce your risk of infection.
Slater LN, Welch DF. Bartonella, including cat-scratch disease. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 235.
Stechenberg BW. Bartonella. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 201.
|Review Date: 8/31/2014
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.