Cat Scratch Fever or Cat Scratch Disease (CSD): Swollen Lymph Nodes After Kitten Scratch or Bite
Cat Scratch Disease (CSD) is a zoonotic Infection from a Bartonella henselae organism. Fleas carry the disease and infect the cat with Bartonella henselae. It is transmitted to people by a cat licking, biting, or scratching human skin. On rare occasion petting an infected cat and then rubbing one’s eyes have passed it. The cat doesn’t appear sick. Within 14 days of transmition a lymph node becomes swollen near the site of initial infection. This nonfatal disease was first described around 1889.
Lymph Node Swelling is a Primary Symptom
A papule forms at the site shortly after possible exposure by the infected cat’s saliva or blood. The papule may look like an insect bite or pimple and be ignored for a while. When a lymph node swells some 2 weeks later often no relationship between the papule and the node is made. Sometimes there may be swelling of 3 nearby lymph nodes. The area may be red and tender. There may be a mild fever, no higher than 101 for a few days and a feeling of fatigue. By the time the nodes are ½ inch to 4 inches large medical attention is sought.
Diagnosis Based on History of Cat Related Event and Henselae Titer
Without associating the lymph node development with cat contact some weeks earlier, patients are often subject to a series of tests for various diseases marked by enlarged lymph nodes such as cancer and tuberculosis. Before the ability to measure the henselae titers, the diagnosis was one of exclusion by biopsy, TB tine tests, mononucleosis, blood work, and history of recalled events with a cat. Today, a titer of 1:64 or more is diagnostic along with recall of the cat event.
CSD is Often Self Limiting
It will disappear on its own within 4 months. Antibiotics may be given because it is a bacterium. The cat, if a pet, is given a flea bath. For most people there is no long term after effect from the incident and once the diagnosis is given people feel better immediately knowing they don’t have a life threatening disease. It isn’t contagious from person to person. In some cases with severely immune suppressed patients the recovery may take longer.
Incidence of Cat Scratch Disease
The highest incidence seems to be in children under 10 years of age although this may be due to that age group seen more often by doctors. Some 22,000-24000 people are infected in the US each year.
Cats under one year are more often affected than older cats. CSD occurs throughout the world and varies in different cat populations. It is more common in warm humid climates (Florida) than cold (0% in Norway). It is more common in stray cats than in house pets. Following the cat flea population density, incidence of the disease peaks in the fall and winter.
Protection from Cat Scratch Fever
- Avoid teasing play with cats, especially kittens. Avoid getting scratched.
- Immediately wash scratches and bites thoroughly with warm water and soap.
- Control your pets’ fleas, whether dogs or cats with flea baths or monthly treatments as recommended by your veterinarian.
- Cover open wounds when handling animals.
- See your healthcare provider for any cat scratch or bite which appears warm, red, or infected.