Cat Scratch Disease Causes Symptoms Diagnosis and FAQ

Cat Scratch Disease

What is Cat Scratch Disease?

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Cat-scratch disease (CSD), also known as Bartonellosis or Carrion’s disease, is a bacterial infection that causes lymph node swelling in the affected area. It can be transmitted from cats to humans by a bite or scratch, or from kittens to humans when the bacteria is transferred from the mother cat’s milk while nursing. Cats are the only known carriers of bacteria.

CSD is not considered a “reportable” disease because it doesn’t cause serious illness or death often enough to be of concern. However, it is still important to understand the disease and its symptoms so that it can be treated at an early stage to avoid complications.

History of Cat Scratch Disease

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Cat scratch disease was first described in the 1960s when it was noticed that lymphadenopathy is often found in children who keep cats as pets or are frequently in contact with them.

Primary or Viral Cat Scratch Disease: This is the most common form of cat scratch disease, where the organism involved is Bartonella henselae. Patients with this type of cat scratch disease usually have an acute febrile illness followed by a papulovesicular rash at the inoculation site. The skin lesion is usually accompanied by regional lymphadenopathy. The spleen and liver are often enlarged, but there may be no end-organ damage.

The primary cat-scratch disease has been associated with bathing cats and convincing cats to lick open wounds (i.e., on the hand).

Bacteremia: Bacteremia occurs in approximately 5% of untreated cases. The rate of bacteremia is lower for patients with the primary cat-scratch disease compared to those with reactivated cat-scratch disease (secondary or post-infectious).

Reactivated Cat Scratch Disease: This form occurs months after the patient has had primary cat scratch disease and it can manifest by any of the following conditions:

regional lymphadenopathy, most commonly of the cervical lymph nodes





chills, myalgia, or arthralgia


An atypical presentation is also possible, with swollen lymph nodes and patients who present with skin lesions near the inoculation site.

What Are The Causes of Catch Scratch Disease?

The CDC reports that there are three major causes of cat scratch disease:

coming into contact with an infected cat’s mouth, claws, or fur

being scratched or bitten by a cat that has the infection

swallowing food or water that has been contaminated with secretions from an infected cat.

There are other ways one could contract the bacteria, but these are the three most common ways. The CDC also reports that instances of fatal cases are rare.

What Are The Symptoms of Cat Scratch Disease?

Symptoms appear anywhere from one week to three months after exposure and include:


swollen lymph nodes (usually in the armpits, groin, or neck)

aching and soreness around the site of where you were scratched or bitten.

This pain can last for weeks or even months if left untreated. If there is any swelling near the eye, difficulty breathing, abdominal swelling like bloating, vomiting blood, headache very bad headache, stiff neck with little to no movement possible, mental changes such as confusion/disorientation/memory loss these may be signs that it’s going on to something worse called septicemia which basically means your blood has become pretty much infected.

Additionally, you might experience general malaise, fatigue, weight loss, and/or develop an enlarged spleen.

Is Cat Scratch Disease Contagious?

Yes, it is contagious. However, the odds of transmitting the bacteria to another individual are low if certain precautions are taken. Since cats are often in close contact with other cats in the household, taking certain precautions can reduce the spread of the bacteria.

How Does Cat-Scratch Disease Spread?

Bartonella henselae bacteria are carried by cats and transmitted through scratches or bites. The bacteria often enter through breaks in the skin, infecting nearby lymph nodes. People with compromised immune systems are at greater risk for contracting the cat-scratch disease because their bodies cannot fight off infections as easily as an average person would be able to.

The most common symptoms of Cat Scratch Disease are: Fever/Chills Headache Sore Throat Swollen Lymph Nodes (generally found on side of the neck) Atypical Rashes (rash on palms of hands and bottoms of feet)

If you are experiencing any other symptoms, please seek medical attention immediately.

How is Cat-Scratch Disease Diagnosed?

There are several ways that doctors diagnose cat-scratch disease. Physicians will usually take a thorough medical history and conduct a physical exam to determine if someone has contracted the disease. They can often diagnose cat-scratch disease via clinical examination alone, but it is not always foolproof because there are other conditions that may mimic cat-scratch disease’s symptoms.

Doctors will typically use clinical examinations and laboratory tests to determine if someone has contracted the cat-scratch disease. A lymph node biopsy or skin scrape can reveal if a person has Bartonella henselae bacteria under their skin. Blood tests can show whether someone has antibodies to the cat-scratch disease in their bloodstream, which indicates infection has occurred at some point in time. Since not everyone who contracts the disease exhibits symptoms, blood tests are often used for early detection purposes rather than diagnosing the disease itself.

Early diagnosis of this disease is very rare, but if caught early enough it can be treated with antibiotics.

What is the Treatment for Cat-Scratch Disease?

Although most cases of cat-scratch disease resolve on their own, treatment with antibiotics can speed recovery and prevent serious complications. Antibiotics such as azithromycin or amoxicillin are commonly prescribed to treat cat-scratch disease. If you suspect that you might have contracted this disease, seek medical attention immediately.

The disease is self-limited, and treatment consists of:

amoxicillin for 7 to 10 days

azithromycin or erythromycin for 10 to 21 days.

Both of these antibiotics are used in the same dosage range as they both achieve similar concentrations in tissue and serum when given orally.

Azithromycin is preferred over erythromycin because it does not lower the seizure threshold on rare occasions that seizures occur secondary to cat-scratch disease.

If you have a Bartonella henselae infection, you will be given a prescription for an antibiotic. You should never take antibiotics that were not prescribed by a doctor, as doing so could make the infection worse.

Antibiotics are used in most cases to treat cat-scratch disease, but antibiotics alone will not alleviate all symptoms. The fever and swollen lymph nodes may persist after treatment with an antibiotic because these symptoms are a manifestation of your own immune system’s response to the cat-scratch disease.

If there are any other symptoms, you should continue taking antibiotics until they resolve. If symptoms continue for more than a few days after treatment with antibiotics, you should return to your doctor for further evaluation.

People with the cat-scratch disease who do not have compromised immune systems usually recover within 1 to 2 weeks.

The prognosis for people with healthy immune systems is generally very good. Symptoms typically disappear within a few weeks and people recover fully within a few months.

If you experience any symptoms of the cat-scratch disease after being bitten or scratched by a cat or kitten, please contact your physician immediately. If the cat is showing signs of illness, it should be taken to a veterinarian. In rare cases, the cat may develop feline leukemia or feline immunodeficiency virus infections and can transmit these diseases to humans and other cats.

If you do not have a cat or kitten, it is important that you do not adopt one as this can further increase your risk of contracting feline infectious diseases.

Although the cat-scratch disease is usually a mild illness, it can be serious for people with weakened immune systems. If you are pregnant or have a compromised immune system, please contact your doctor if you notice any symptoms of the cat-scratch disease.

When you feel any discomfort after being bitten or scratched by a cat, please seek medical attention immediately. Your doctor will determine the best course of treatment to help you recover from the cat-scratch disease.

If your doctor prescribes medication, expect all of your symptoms to clear up within a week. However, some people do not experience relief from their symptoms until several weeks after beginning antibiotic therapy. Additionally, taking antibiotics for too long may cause antibiotic resistance and/or yeast infections. It’s important to finish everything exactly as your doctor tells you even if you feel better.


Q: What is cat scratch disease?

A: Cat-scratch disease, also called bartonellosis, is an infectious disease carried by cats.

Q: Are there any other names for cat scratch disease?

A: Cat scratch disease is also known as bartonellosis, and it can be referred to as cat-scratch fever or cat-scratch fever complex.

Q: How is the disease spread?

A: The Bartonella henselae bacterial infection is spread through a cat’s scratch or bite.

Q: How common is it?

A: Cat-scratch disease is very uncommon. It affects about 24,000 people a year in the United States.

Q: What are the symptoms of cat scratch disease?

A: Cat-scratch disease usually does not cause any symptoms or very mild ones. However, in some cases, the cat-scratch disease can cause serious problems.

Q: How does cat scratch disease affect the body?

A: It can affect children of any age but it is more common in children younger than 7 years.

Q: How does cat scratch disease affect the eyes?

A: Cat-scratch diseases can cause serious eye problems.

Q: How does cat scratch disease affect the brain?

A: Cats-scratch disease can affect the eyes, brain, and heart.

Q: How does cat scratch disease affect the skin?

A: Cats-scratch disease can cause painful sores on the skin.

Q: How does cat scratch disease affect the kidneys?

A: Cats-scratch disease can cause painful swelling of the lymph nodes and kidneys.

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