Cat scratch fever typically starts as a small, raised bump at the site where a cat scratched or bit you, then progresses to noticeably swollen lymph nodes near the wound within one to three weeks. The appearance changes as the infection moves through stages, and knowing what to look for at each point helps you recognize it early.
The First Sign: A Bump at the Scratch Site
The earliest visible sign is a papule or pustule that forms right where the cat broke your skin. This small, raised bump looks similar to an insect bite or a minor pimple. It can appear on the hands, arms, face, or anywhere else the scratch or bite occurred. Because it’s so unremarkable, many people don’t think much of it. The bump typically shows up a few days to a couple of weeks after the initial scratch, often after the scratch itself has already started to heal.
Swollen Lymph Nodes: The Hallmark Sign
The most recognizable feature of cat scratch fever is regional lymphadenopathy, which simply means the lymph nodes closest to the scratch become swollen and tender. If you were scratched on your hand or forearm, the nodes in your armpit or elbow crease swell up. A scratch on the face or neck tends to cause swelling in the neck or jaw area. The swollen nodes can range from marble-sized to golf ball-sized, and they’re usually warm to the touch and sometimes painful.
About 85 to 90 percent of otherwise healthy children with cat scratch disease develop this kind of localized lymph node swelling. It’s self-limited in most cases, meaning it resolves on its own, but the swelling can persist for weeks or even a few months. In some cases the node becomes so inflamed it develops into an abscess that may need to be drained. Fewer than half of patients actually develop a fever alongside the swelling, so you can have a clear case of cat scratch disease without ever feeling feverish.
Skin Rashes Beyond the Scratch
Most people only see the initial bump and the swollen nodes. But up to 24 percent of patients develop atypical presentations, and some of those involve skin changes elsewhere on the body.
A maculopapular rash, which looks like flat red patches mixed with small raised bumps spread across the skin, occurs in roughly 6 to 7 percent of cases. About 2 to 2.5 percent develop erythema nodosum: tender, reddish or purplish lumps that typically appear on the shins. These lumps sit deeper under the skin than a typical rash and feel firm and painful when pressed. Less commonly, some people develop hives or a condition called cutaneous vasculitis, where small blood vessels in the skin become inflamed, producing reddish-purple spots.
What It Looks Like in the Eye
When the bacteria enter through the eye (from rubbing your eye after contact with a cat), the result is a condition called Parinaud oculoglandular syndrome. It looks a lot like pink eye: the affected eye turns red, irritated, and painful. The key difference is the appearance of small, raised nodules on the inside of the eyelid or on the white of the eye. The lymph nodes in front of the ear on the same side also swell up noticeably. This combination of an angry-looking eye plus a swollen preauricular node is the visual giveaway.
A rarer eye complication called neuroretinitis occurs in 1 to 2 percent of cases. You wouldn’t see this one in the mirror, but it causes sudden vision loss or blurriness. During an eye exam, the back of the eye shows swelling of the optic disc along with a distinctive “macular star,” a starburst pattern of yellowish-white deposits radiating outward from the center of the retina. The optic disc swelling appears first, and the star pattern develops afterward as fluid migrates into the deeper retinal layers and crystallizes into that recognizable shape.
How It’s Diagnosed
There’s no single test that definitively confirms cat scratch disease. Diagnosis relies on a combination of factors: a history of contact with a cat plus a visible scratch or primary skin lesion, swollen lymph nodes in the expected region, ruling out other causes of the swelling, and sometimes a blood test for antibodies against the Bartonella henselae bacterium. The bacteria are difficult to grow from tissue samples in a lab, so doctors often use PCR testing, which detects bacterial DNA directly from a lymph node sample, to confirm the diagnosis when the clinical picture isn’t clear enough on its own.
In practice, many straightforward cases are diagnosed based on the classic appearance alone: a patient with a cat at home, a healing scratch, and a tender, swollen lymph node nearby. The trickier cases are the atypical ones, where someone shows up with an unexplained fever, a rash, or eye problems without an obvious scratch to point to.
What Recovery Looks Like
For most healthy people, the visible signs of cat scratch fever resolve gradually over weeks to months without specific treatment. The initial bump at the scratch site fades first, while the swollen lymph nodes take the longest to return to normal, sometimes lingering for two to four months. During this time, the node slowly shrinks and becomes less tender. In cases where lymph nodes become large and fluctuant (soft and fluid-filled), they may need to be aspirated with a needle to relieve pressure and speed healing.
The atypical presentations, including eye involvement, rashes, and organ inflammation, generally require antibiotic treatment and take longer to fully resolve. Vision changes from neuroretinitis usually improve significantly once treatment begins, though complete recovery of the macular star pattern on eye exam can take several weeks.