Bartonellosis (Cat Scratch Disease)

Symptoms

Common signs and symptoms of Bartonellosis (Cat Scratch Disease) include:

Small red bump or blister at the scratch site

Swollen lymph nodes near the scratch area

Lymph nodes that feel tender or painful to touch

Low-grade fever lasting several days

Fatigue and general feeling of being unwell

Headache that persists for days

Loss of appetite and mild nausea

Body aches similar to flu symptoms

Skin warmth around swollen lymph nodes

Lymph nodes that may feel firm or rubbery

Occasional night sweats

Mild joint pain in arms or legs

When to see a doctor

If you experience severe or worsening symptoms, seek immediate medical attention. Always consult with a healthcare professional for proper diagnosis and treatment.

Causes & Risk Factors

Several factors can contribute to Bartonellosis (Cat Scratch Disease).

Cat scratch disease results from infection with Bartonella henselae, a rod-shaped bacterium that lives in the bloodstream of infected cats.

Cat scratch disease results from infection with Bartonella henselae, a rod-shaped bacterium that lives in the bloodstream of infected cats. Fleas serve as the primary way this bacterium spreads from cat to cat, picking up the bacteria when they feed on an infected cat's blood and then transmitting it to other cats through their bites. Cats can carry these bacteria for months without showing any signs of illness.

Humans become infected when the bacteria enters through breaks in the skin caused by cat scratches, bites, or even licks over open wounds.

Humans become infected when the bacteria enters through breaks in the skin caused by cat scratches, bites, or even licks over open wounds. The bacteria doesn't penetrate healthy, intact skin, which explains why the infection typically develops at sites where the skin has been broken. Interestingly, some people develop the infection without remembering any specific incident with a cat, suggesting that very minor scratches can sometimes be enough.

The bacteria multiply at the entry site and then travel through the lymphatic system to nearby lymph nodes, where they trigger an inflammatory response.

The bacteria multiply at the entry site and then travel through the lymphatic system to nearby lymph nodes, where they trigger an inflammatory response. This explains why swollen lymph nodes typically appear in the area closest to the original scratch. The body's immune system eventually clears the infection in most healthy individuals, though this process can take several weeks to months.

Risk Factors

Owning cats, especially kittens under one year old
Being scratched or bitten by cats regularly
Living in warm, humid climates where fleas are common
Having a weakened immune system from illness or medications
Children and young adults who play roughly with cats
Contact with stray or feral cats
Poor flea control in households with cats
Working with cats professionally (veterinarians, shelter workers)
Recent adoption of a new kitten or young cat

Diagnosis

How healthcare professionals diagnose Bartonellosis (Cat Scratch Disease):

1
Diagnosing cat scratch disease often begins with a careful review of recent contact with cats and examination of symptoms.
Diagnosing cat scratch disease often begins with a careful review of recent contact with cats and examination of symptoms. Doctors look for the characteristic combination of a healing scratch or bite mark along with swollen lymph nodes in the corresponding area of the body. The medical history becomes crucial since many patients initially forget about minor cat scratches that occurred weeks earlier.
2
Blood tests can confirm the diagnosis by detecting antibodies against Bartonella henselae or identifying the bacteria's genetic material.
Blood tests can confirm the diagnosis by detecting antibodies against Bartonella henselae or identifying the bacteria's genetic material. The most commonly used test measures IgG and IgM antibodies, though it can take several weeks after infection for these to reach detectable levels. In some cases, doctors may perform a lymph node biopsy, particularly if the swelling is extensive or other conditions need to be ruled out.
3
Doctors must distinguish cat scratch disease from other conditions that cause similar symptoms, including other bacterial infections, viral infections like mononucleosis, and less commonly, certain types of cancer.
Doctors must distinguish cat scratch disease from other conditions that cause similar symptoms, including other bacterial infections, viral infections like mononucleosis, and less commonly, certain types of cancer. The combination of cat exposure, characteristic symptoms, and positive blood tests usually provides a clear diagnosis. Imaging studies like ultrasound or CT scans are occasionally used when lymph node swelling is particularly prominent or located in areas that are difficult to examine.

Complications

While most people recover from cat scratch disease without lasting effects, complications can occasionally develop, particularly in people with weakened immune systems.
The most common complications involve the eyes, such as Parinaud's oculoglandular syndrome, which causes swelling of the lymph nodes near the ears along with eye redness and irritation.
This typically resolves with appropriate treatment.
Rarer but more serious complications can affect the nervous system, including encephalitis (brain inflammation), seizures, or inflammation of the optic nerve.
These neurological complications are uncommon but require immediate medical attention and specialized treatment.
Other potential complications include infection of the liver, spleen, or bone, though these occur in less than 2% of cases.
Most complications develop within the first few weeks of infection and respond well to antibiotic treatment when caught early.

Prevention

Avoid rough play with cats, especially kittens
Wash hands thoroughly with soap and water after handling cats
Clean any cat scratches or bites immediately with soap and water
Apply antiseptic to wounds and monitor for signs of infection
Keep cats' nails trimmed to minimize scratch severity
Control fleas on cats using veterinarian-recommended treatments

Treatment Approaches

Most cases of cat scratch disease in healthy individuals resolve without specific treatment, as the body's immune system effectively clears the infection over time.

Most cases of cat scratch disease in healthy individuals resolve without specific treatment, as the body's immune system effectively clears the infection over time. Doctors often recommend supportive care including rest, adequate hydration, and over-the-counter pain relievers like ibuprofen or acetaminophen to manage discomfort from swollen lymph nodes and fever.

Home Remedy

Antibiotics may be prescribed for patients with severe symptoms, compromised immune systems, or complications affecting the eyes, brain, or other organs.

Antibiotics may be prescribed for patients with severe symptoms, compromised immune systems, or complications affecting the eyes, brain, or other organs. Azithromycin is typically the first-choice antibiotic, usually given for five days. Other options include clarithromycin, erythromycin, or doxycycline, depending on the patient's age and medical history.

Antibiotic

Warm compresses applied to swollen lymph nodes can provide comfort and may help reduce swelling.

Warm compresses applied to swollen lymph nodes can provide comfort and may help reduce swelling. However, these lymph nodes should never be drained or surgically removed unless absolutely necessary, as this can lead to chronic drainage problems. Most lymph node swelling resolves gradually over several weeks to months.

Surgical

For the rare cases that develop complications like Parinaud's oculoglandular syndrome (eye involvement) or encephalitis, more intensive treatment may be required.

For the rare cases that develop complications like Parinaud's oculoglandular syndrome (eye involvement) or encephalitis, more intensive treatment may be required. These patients often need hospitalization and specialized care from infectious disease specialists or other relevant specialists depending on the organs affected.

Living With Bartonellosis (Cat Scratch Disease)

Living with cat scratch disease typically means managing symptoms while the body naturally clears the infection. Most people can continue their normal activities with some modifications for comfort. Rest when feeling fatigued, and avoid heavy lifting or strenuous activities that might aggravate swollen lymph nodes.

Pain management becomes important since lymph node swelling can persist for weeks or months.Pain management becomes important since lymph node swelling can persist for weeks or months. Over-the-counter pain relievers, warm compresses, and loose-fitting clothing around affected areas can help. Monitor the healing process and watch for signs that might indicate complications, such as vision changes, severe headaches, or worsening symptoms after initial improvement.

Once recovered, people can safely return to normal contact with cats.Once recovered, people can safely return to normal contact with cats. Having cat scratch disease once provides some immunity against future infections, though reinfection is theoretically possible. Continue practicing good hygiene and wound care around cats, but there's no need to avoid feline companionship. Regular follow-up with healthcare providers ensures proper healing and addresses any concerns that arise during recovery.

Latest Medical Developments

Latest medical developments are being researched.

Frequently Asked Questions

Can I catch cat scratch disease from indoor cats?

Yes, indoor cats can carry Bartonella bacteria, especially if they had flea exposure before coming indoors or if fleas are brought inside on clothing or other pets. However, indoor cats are generally less likely to be infected than outdoor cats.

How long after a cat scratch do symptoms appear?

Symptoms typically develop 3 to 14 days after being scratched or bitten. The initial bump at the scratch site usually appears first, followed by lymph node swelling 1 to 3 weeks later.

Can I get cat scratch disease without being scratched?

Yes, the infection can occur through cat bites or when cats lick open wounds or broken skin. Some people develop the disease without remembering a specific scratch, possibly from very minor skin breaks.

Should I get rid of my cat if I have cat scratch disease?

No, there's no need to get rid of your cat. With proper flea control and careful handling, you can safely keep your pet. The cat is unlikely to reinfect you once you've recovered.

How long do swollen lymph nodes last?

Swollen lymph nodes typically persist for 2 to 4 months, though they can occasionally last longer. The swelling gradually decreases over time as your body clears the infection.

Is cat scratch disease contagious between people?

No, cat scratch disease does not spread from person to person. You can only get it from infected cats, so family members don't need to worry about catching it from you.

Can I exercise normally with swollen lymph nodes?

Light exercise is usually fine, but avoid strenuous activities that might aggravate swollen lymph nodes. Listen to your body and rest when you feel fatigued or uncomfortable.

Do all cats with fleas carry the bacteria?

No, only some cats carry Bartonella bacteria, even those with fleas. Studies suggest that 20-40% of cats may be infected at any given time, with higher rates in young cats and those in warm climates.

Should I take antibiotics for cat scratch disease?

Antibiotics aren't always necessary for healthy people with typical symptoms. Your doctor will decide based on the severity of your symptoms and your overall health status.

Can cat scratch disease come back?

Reinfection is rare because having the disease once usually provides some immunity. However, people with severely compromised immune systems might be at higher risk for repeat infections.

Update History

Apr 9, 2026v1.0.0

Published by DiseaseDirectory