Cats that spread the infection do not look sick. The infection is not spread from person to person. A blister or sore, with or without pus or fluid, often shows up on the skin at the place where the bacteria entered the body. Within 2 weeks, the lymph glands nearby usually become swollen and tender. In most children and adolescents, swollen glands are the main symptom.
Adults often have other symptoms such as low fever, tiredness, headache, and loss of appetite.
Persons with weakened immune systems can become more seriously ill. It usually takes 3 to 10 days for a sore to appear at the site of a cat scratch or bite. The lymph glands nearby usually start to swell about 2 weeks after the scratch or bite. Diagnosis is based on symptoms and a history of a scratch by a cat. A blood test can confirm the diagnosis.