Cat scratch fever, known medically as cat scratch disease, usually resolves on its own within a few weeks to a few months without any specific treatment. Most healthy people recover fully with basic home care. In more severe cases or for people with weakened immune systems, antibiotics can speed recovery and prevent complications.
What Cat Scratch Fever Looks and Feels Like
The infection starts when the bacterium Bartonella henselae enters your skin through a cat scratch, bite, or even a lick over broken skin. Within 3 to 14 days, a small raised bump or blister typically forms at the scratch site. This initial bump is easy to miss or mistake for a bug bite, but it’s the first sign the bacteria have taken hold.
One to three weeks after that bump appears, nearby lymph nodes swell and become tender. If the scratch was on your hand or arm, you’ll usually notice swelling in the armpit or elbow area. A scratch near the face can cause swelling around the ear or neck. These swollen nodes can grow to several centimeters and feel warm and painful to the touch. You may also develop a low-grade fever, fatigue, headache, decreased appetite, and joint pain.
Home Care for Mild Cases
For most otherwise healthy people, cat scratch fever doesn’t require prescription medication. The infection runs its course, and swollen lymph nodes gradually shrink over two to four months, sometimes longer. During that time, you can manage discomfort with a few simple measures:
- Over-the-counter pain relievers. Ibuprofen or naproxen can reduce both pain and inflammation around swollen nodes.
- Warm compresses. Applying a warm, damp cloth to tender lymph nodes for 15 to 20 minutes several times a day helps ease soreness and can improve circulation in the area.
- Rest. If you’re feeling fatigued, your body is fighting the infection. Giving yourself time to rest speeds the process along.
Keep the original scratch or bite clean with soap and water. Avoid squeezing or pressing on swollen lymph nodes, as this won’t help them drain and can increase discomfort.
When Antibiotics Are Needed
Antibiotics are typically reserved for people whose symptoms are severe, whose lymph nodes are extremely swollen or painful, or who have a weakened immune system. Azithromycin is the most commonly prescribed antibiotic for cat scratch disease in otherwise healthy patients, often given as a short course of about five days. For people with compromised immune systems, treatment is more aggressive, sometimes lasting three months or longer to fully clear the bacteria.
Your doctor may also consider other antibiotic options depending on your situation, particularly if you have an allergy or if the infection has spread beyond the lymph nodes. The choice of antibiotic and duration depends largely on how the infection is presenting and your overall health.
Severe and Atypical Complications
In a small percentage of cases, the bacteria spread beyond the lymph nodes and cause problems elsewhere in the body. One notable complication is neuroretinitis, where the infection affects the optic nerve and retina, causing sudden vision changes. This requires antibiotic therapy, and doctors sometimes add oral corticosteroids to improve the visual outcome.
Other rare complications include encephalitis (inflammation of the brain), which can cause confusion, seizures, or severe headache, and bone infections that produce deep, persistent pain. These scenarios are uncommon but more likely in children under five and in adults with weakened immune systems. If a cat scratch or bite becomes red and swollen and you develop flu-like symptoms such as headache, fatigue, joint pain, or fever, it’s worth getting evaluated. Persistent high fevers, vision changes, or confusion after a known cat scratch warrant prompt medical attention.
How Doctors Confirm the Diagnosis
If your doctor suspects cat scratch disease, they’ll usually start by examining the swollen lymph nodes and asking about recent contact with cats. A blood test can detect antibodies against Bartonella henselae, confirming the infection. In some cases, particularly when the diagnosis is uncertain, a doctor may order imaging of the swollen nodes or, rarely, perform a biopsy. Under a microscope, infected lymph node tissue shows a distinctive pattern of inflammation with areas of tissue death surrounded by immune cells clustered in layers.
Getting a clear diagnosis matters because swollen lymph nodes can have many causes, and knowing it’s cat scratch disease helps you and your doctor decide whether to simply wait it out or start treatment.
Preventing Cat Scratch Fever
The bacteria that cause cat scratch disease are spread among cats by fleas. Cats pick up the infection from flea bites or flea droppings that get into small wounds, then carry the bacteria in their bloodstream. Kittens are more likely to be infected than adult cats, and they’re also more likely to scratch during play.
The most effective prevention strategy is keeping your cats on a flea prevention product. The CDC recommends topical or oral flea treatments such as fipronil, methoprene, or imidacloprid for cats. (Permethrin, commonly used on dogs, should never be used on cats because it’s toxic to them.) Keeping cats indoors also reduces their risk of picking up fleas and encountering infected feral cats.
Beyond flea control, a few practical habits lower your risk. Wash any cat scratch or bite immediately with soap and running water. Avoid rough play with cats, especially kittens, that leads to scratches. Don’t let cats lick open wounds or broken skin. If you’re immunocompromised, consider adopting an adult cat rather than a kitten, since kittens are more likely to carry the bacteria and more prone to scratching.