Cat scratch fever typically lasts 2 to 4 months from start to finish in otherwise healthy people, though the worst of the symptoms usually pass much sooner than that. The infection resolves on its own without antibiotics in roughly 90 to 95 percent of cases. What lingers longest is swollen lymph nodes, which can stick around for weeks or even months after you otherwise feel fine.
The Timeline From Scratch to Symptoms
Cat scratch fever follows a fairly predictable sequence. Within 3 to 10 days of being scratched or bitten by an infected cat, a small raised bump (a papule) appears at the wound site. It often looks like a bug bite and is easy to miss or dismiss.
About one to three weeks after the initial scratch, nearby lymph nodes begin to swell. This is the hallmark of the disease and usually the symptom that sends people to a doctor. The nodes closest to the scratch are the ones affected, so a scratch on the hand typically causes swelling in the armpit or elbow area, while a scratch on the face may cause swelling near the ear or neck. The swollen nodes can be tender, warm, and sometimes quite large.
How Long Each Symptom Lasts
The skin papule at the scratch site is usually the first thing to come and go. It tends to fade within a couple of weeks and rarely causes much concern on its own.
Systemic symptoms like fever, fatigue, and general malaise affect a significant portion of patients. Fever above 101°F occurs in roughly a third to over half of cases, while fatigue and malaise show up in about 30 percent. These flu-like symptoms generally clear within one to two weeks, though some people report lingering fatigue beyond that window.
Lymph node swelling is the slowest symptom to resolve. In most people, the nodes gradually shrink over 2 to 4 months. During that time, the swelling may fluctuate. Some nodes become filled with pus and need to be drained, but most simply shrink back to normal size on their own. Warm compresses and over-the-counter pain relievers can help manage the discomfort while you wait it out.
Does Treatment Speed Things Up?
Because the infection clears on its own in the vast majority of cases, antibiotics aren’t always prescribed. When they are, a short five-day course of azithromycin is the most commonly studied option. In a clinical trial comparing azithromycin to a placebo, over half of the patients on the antibiotic saw more than 80 percent of their lymph node swelling resolve within 30 days. Only 1 in 15 patients in the placebo group hit that same benchmark in the same timeframe. So while antibiotics don’t dramatically shorten the overall illness, they can meaningfully speed up the resolution of swollen lymph nodes.
For mild cases, many doctors opt for a watch-and-wait approach with symptom management: pain relief, fever reducers, and warm compresses on tender nodes.
When It Affects the Eyes
In uncommon cases, the bacteria can affect the eyes, causing a condition called Parinaud oculoglandular syndrome (typically from rubbing your eyes after contact with an infected cat) or neuroretinitis, which involves inflammation of the optic nerve and retina.
Parinaud syndrome generally resolves within a few weeks once the underlying infection is treated. Neuroretinitis is more serious and requires a longer course of antibiotics, usually 4 to 6 weeks. The visual outlook is generally good: in one study tracking affected eyes, 80 percent recovered to good vision (better than 20/40), though 6 percent experienced severe vision loss. The key factor is how quickly treatment starts.
A Longer Course for Weakened Immune Systems
The timeline changes significantly for people with weakened immune systems, such as those living with HIV or taking immunosuppressive medications after an organ transplant. In these patients, the same bacteria can cause a more aggressive condition called bacillary angiomatosis, producing skin lesions and potentially affecting the liver and bones.
Treatment in these cases lasts much longer. Skin lesions typically require 8 to 12 weeks of antibiotics, and infections involving the liver or bones need at least 3 months. Some patients with HIV experience relapses and may need ongoing or even lifelong antibiotic therapy to keep the infection in check. Effective management of the underlying immune condition, particularly antiretroviral therapy for HIV, plays a critical role in recovery.
What to Expect Overall
For a healthy person, the practical answer is this: you’ll likely feel sick for one to two weeks, and the swollen lymph nodes will take another one to three months to fully resolve. The infection almost always clears completely without lasting effects. Most people feel well enough to go about their normal routine within a couple of weeks, even if a swollen node near the scratch site serves as a lingering reminder for a while longer.
Children tend to follow the same timeline as adults, with spontaneous resolution rates of 90 to 95 percent. The illness is uncomfortable but rarely dangerous in people with normal immune function.