Cat scratch disease

Marian Grosser studied human medicine in Munich. In addition, the doctor, who was interested in many things, dared to make some exciting detours: studying philosophy and art history, working on the radio and, finally, also for a Netdoctor.

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Cat scratch disease is caused by bacteria. The pathogen enters the human body mainly through scratches in cats. Cats themselves do not get sick or only slightly. The disease is usually harmless and heals on its own after a few weeks. In certain cases, however, the use of antibiotics can be useful. Read everything about cat scratch disease, who it affects and how it is treated here.

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. A28

Cat scratch disease: description

Cat scratch fever is an infectious disease caused by bacteria of the genus Bartonella. The house cat is the carrier of the pathogen. She does not get sick herself or shows only minor symptoms.

The name of the disease goes back to the French doctor Robert Debré, who found scratching injuries caused by domestic cats in the sick. Cat scratch disease is rare, but it is widespread worldwide and occurs more frequently in autumn and winter.

Cat scratch disease: symptoms

After a person has become infected with the pathogen, the first symptoms appear after two to ten days.

At the point of skin where the bacterium entered the body, small red-brown nodules initially appear, which can easily be mistaken for an allergic reaction. The nodules do not itch or hurt and disappear after a few days or weeks.

In the human body, the bacteria first attack the lymph nodes near the skin lesion. These swell and can be painful. Eventually, the lymph nodes in the neck or armpit also enlarge. The following symptoms can also occur:

• Fever (usually mild) and chills
• Exhaustion
• Pain in the limbs, stomach, head and throat
• Loss of appetite
• recurrent nausea and vomiting

Sometimes the lymph node swellings appear all over the body as the cat scratch disease progresses. The liver and spleen also occasionally swell, which leads to an uncomfortable feeling of pressure in the upper abdomen. Conjunctivitis on the eye caused by bacteria is particularly painful. The nervous system can also be attacked by the pathogen. Meningitis, inflammation of the eye nerves or the spinal cord are the result.

It is also possible that those affected have no symptoms other than the swollen lymph nodes. While symptoms such as fever, feeling sick, or nausea will soon go away, the lymph node swelling sometimes lasts for months and can also become a cosmetic problem. However, they are not dangerous.

Cat scratch disease: causes and risk factors

Cat scratch disease can affect anyone. Due to the transmission path, however, cat owners are particularly at risk. Since young animals in particular are contagious, cat scratch disease occurs more frequently in households with very young cats. But older animals can also transmit the disease - 10 to 13 percent of all cats in Germany are said to be infected.

Most people who get cat scratch disease are younger than 21 years of age or in childhood. The reason: Children often have close contact with pets, but on the other hand they do not yet have a fully developed immune system. Adult people with an immune deficiency also develop cat scratch disease more often and sometimes show a more severe course.

Transmission of the bacteria

The pathogen causing the cat's disease mainly reaches the cat's claws in three ways:

• If the animal licks its paws, the bacteria that are in its saliva and blood get to the claws.
• If a flea settles in the cat's fur and sucks its blood, the pathogens get into the insect. They are excreted in the excrement of the flea and are then found in the cat's fur. The puncture site itches, which is why the cat scratches itself. The feces of the flea get under their claws.
• If the cat licks a previously scratched or otherwise damaged skin area, the pathogen can also be transmitted.

Since the cat flea also bites people, direct transmission of the pathogen is also possible, but far less often. A transmission of the Bartonella bacteria from person to person has not yet been observed.

Cat scratch disease: examinations and diagnosis

The symptoms of cat scratch disease are often very different and can also occur with other diseases. It is therefore important for the doctor to know how the disease developed and whether there are cats in the household.

Furthermore, the blood must be examined by taking a blood sample. If the body has had contact with the pathogen causing cat scratch disease, it forms specific antibodies against the bacterium, which can be detected in the blood. Special procedures can detect the pathogen very quickly in blood or tissue samples.

You can also try to “cultivate” the pathogen using a blood sample. However, this takes a few weeks to achieve a clear result. Sometimes you have to take tissue from a swollen lymph node in order to be able to diagnose the disease with certainty.

Cat scratch disease: treatment

In most cases, cat scratch disease heals on its own, so special treatment is not necessary. Pain relievers such as ibuprofen or paracetamol can help with symptoms such as fever and pain. Cooling pads relieve the pain in swollen lymph nodes.

Sometimes the cat scratch disease lasts longer or the symptoms are very pronounced. Then antibiotics can be used and shorten the course of the disease.

Cat scratch disease: disease course and prognosis

In most cases, cat scratch disease is harmless. However, complications can rarely occur if the bacteria attack the bones, heart or lungs, for example, and cause inflammation there.

Because the Bartonella bacteria also attack the red blood cells, they sometimes perish. If the pathogens in the blood multiply too much, this can lead to blood poisoning (sepsis) and anemia (anemia). Blood poisoning is life-threatening and must be treated in an intensive care unit.

The cat-scratch disease for immune deficiency

People with an immune deficiency have an increased risk of contracting cat scratch disease. In this case, the disease can also be severe or cause rare symptoms.

Bacillary angiomatosis

If the immune system is weakened as part of an HIV infection, for example, the bacterium Bartonella can trigger what is known as bacillary angiomatosis. The pathogen multiplies in the smallest blood vessels in the skin and on organs such as the liver, spleen and eyes, as well as on the lymph nodes and the nervous system.

The tiny blood vessels begin to grow and appear in the skin as small dark red to purple nodules. They occur individually or in groups and are partially distributed over the entire body. As it progresses, the nodules can break open, bleed, and become inflamed. Small blood-filled cavities (cysts) can develop in the liver.

Preventive measures

As the main preventive measure, fleas in domestic cats should be controlled radically. It is advisable to wash your hands after contact with the cat. People with immunodeficiency should stay away from cats as the main preventive measure against cat scratch disease.

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