Cat scratch disease

Cat scratch disease (formerly written as cat scratch disease) is caused by the scratch of a cat or by pricking the spines or thorns of plants. A bacterium penetrates the skin and causes cat scratch disease. In most cases, the course of the disease is favorable and eventually heals on its own. However, the disease can be accompanied by fever and blisters on the skin. The lymph nodes or nodes become swollen. In severe cases, meningitis develops.

Cause of cat scratch disease

The causative agent for cat scratch disease is the bacterium Bartonella henselae and sometimes also Bartonella clarridgeia. Bartonella henselae is a bacterium that is commonly found in cats, where the bacterium can multiply well. A cat can transmit the bacteria to other cats or to people. Young cats in particular are more likely to be infected with the bacteria. Older cats have built up a defense more often. Most cats do not become ill from the bacteria, so it is often unknown whether a cat is a carrier. The bacteria is also spread via fleas. Humans are almost never bitten by the dog or cat flea, which means that infection via fleas to humans rarely occurs. More than 2,000 people in the Netherlands contract the disease every year. It is estimated that this is probably even higher, because many people with mild complaints do not visit their GP.


The bacterium penetrates human skin through a cat’s scratch or by pricking a spine or thorn on a plant. When the cat or plant is infected with the bacteria, it can penetrate the skin very quickly. If measures are not taken immediately, the bacteria can penetrate deeper into the skin and cause an infection. Disinfecting the wound after a cat scratch or pricking a plant is therefore recommended. Disinfecting will never completely remove the risk, but it will reduce the chance of contamination.


The first symptoms occur 2 to 3 weeks after the injury that caused the infection. The lymph nodes swell and feel painful. At the site of injury, a swelling develops that becomes a blister. This blister will become a scab and disappear on its own. It is not necessary to treat this blister. Sometimes an abscess forms that requires treatment. It is mainly the lymph nodes that patients suffer from. The lymph node inflammation will disappear completely without treatment after 5 to 8 weeks.
In some cases the disease leads to meningitis. This mainly occurs in people whose immune system is weakened. Meningitis is a serious disease that can lead to death. People with a weakened immune system should therefore avoid stinging plants and cats to prevent infection as much as possible. If they have been stung or scratched, it is important to disinfect the wound immediately and thoroughly. At the first symptoms, two to three weeks after the injury, it is necessary to consult a doctor. Cats are not vaccinated against the bacteria, so in principle any cat, including domestic cats, can be infected. Cats that never go outside are much less likely to be infected with the bacteria.


In most cases, treatment is not necessary. The disease will heal on its own. It is also not always necessary to go to the doctor if there are only mild symptoms. The doctor will not be able to do much beyond that. With abscesses it is often necessary to remove the pus. Do not do this yourself, the doctor can do this better. If the immune system is weakened, the symptoms will be much more severe. Then treatment is necessary. Lymph nodes can start to fester. This makes the healing process longer. The lymph nodes can then be opened through surgery. When a fistula has formed, the lymph node will be removed. There is little point in administering antibiotics. Meningitis requires admission to hospital. Cats that appear to be infected can be treated with antibiotics. This seems to be working for them.
There is no clear test yet that can detect cat scratch disease. A test is used that checks the blood for antibodies against the disease. When these are present in the blood, it is clear that the patient has cat scratch disease. However, not every test is equally reliable. For example, some tests have found antibodies against cat scratch disease, even though the patient did not have the disease. It is important that the disease is properly detected, especially for people with a lowered immune system. In this group, cat scratch disease can be fatal. If you have complaints that are becoming more serious or do not disappear on their own, contact a doctor as soon as possible. Do this especially if you know that you have come into contact with a cat’s nails or with stinging or stinging plants and when your defenses are lowered.

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