Cat scratch fever
Cat scratch fever, also known as cat scratch disease (CSD), is an infection caused by the bacterium Bartonella henselae. It's commonly identified by swollen lymph nodes, skin bumps (papules), and fever. This disease is usually transmitted to humans through cat scratches, bites, or when a cat licks an open wound.
How Common is Cat Scratch Fever?
Cat scratch disease is relatively rare, with around 12,000 cases diagnosed annually in the United States.
How Serious is Cat Scratch Fever?
While cat scratch disease typically resolves on its own and is not usually serious, it can sometimes lead to complications requiring hospitalization. Each year, about 500 people in the U.S. are hospitalized due to severe cases.
Who’s Most at Risk?
Anyone in contact with cats can contract cat scratch disease, but it's most frequently seen in children under 15. Those with weakened immune systems, including individuals living with HIV, are at a higher risk for severe complications.
What Does Cat Scratch Fever Look Like?
The hallmark signs of cat scratch disease are swollen lymph nodes and skin papules or cysts. These bumps may look like a rash or nodules and usually appear near the site of the scratch or bite.
What Are the Symptoms?
Symptoms generally show up three to ten days after being scratched, bitten, or licked by a cat. They include:
- Skin papules or a rash
- Painful, swollen lymph nodes
- Fever
- Muscle and joint aches
- Loss of appetite
- Weight loss
- Fatigue
What Causes Cat Scratch Disease?
Cat scratch disease is caused by the bacterium B. henselae. The infection occurs when a cat’s saliva, containing the bacteria, enters a person’s body through an open wound.
How Does It Spread?
B. henselae is often spread to cats by fleas. Cats, especially kittens, can carry the bacteria without showing symptoms and pass it to humans through bites, scratches, or saliva contact with an open wound.
How is It Diagnosed?
Diagnosis involves a physical examination of the scratch or wound, checking for skin papules or a rash, and assessing lymph nodes. Blood tests can detect B. henselae bacteria, and in rare cases, fluid from an enlarged lymph node might be tested.
How is It Treated?
Cat scratch disease often resolves on its own. Treatment typically focuses on symptom management. Antibiotics like azithromycin may be prescribed if symptoms persist or for individuals with compromised immune systems.
How Can I Prevent It?
To reduce your risk:
- Avoid cat bites and scratches
- Wash hands after handling cats
- Keep cats indoors to reduce flea exposure
- Avoid petting or picking up stray cats
- Prevent cats from licking open wounds
What’s the Outlook?
Most people recover from cat scratch disease without any long-term effects. Swollen lymph nodes usually subside within two to eight weeks. However, in rare cases, the infection can spread to other organs and cause more severe illness.
When Should I Be Concerned?
Seek medical attention if a cat scratch results in signs of infection, persistent pain, or other concerning symptoms. High fever, confusion, severe headaches, seizures, chest pain, shortness of breath, or abdominal pain with nausea or vomiting indicate a potential serious infection.
What Questions Should I Ask My Healthcare Provider?
When talking to your healthcare provider, consider asking about:
- The appropriate treatment for your symptoms
- Signs to monitor
- Follow-up recommendations
- When to seek further medical attention
