Flea bites most often cause itching and skin irritation, as stated by the Illinois Department of Public Health. However, some fleas carry tapeworm, bubonic plague and murine typhus, and some people develop an allergic dermatitis reaction to flea bites.
The most common type of fleas in homes are cat fleas, which live on cats and dogs. These pests are unlikely to bite humans unless desperate for food or newly hatched and hungry. People can be host to human fleas, which live on humans and pigs.
Most bites cause a red mark and plenty of itching. In some with sensitive skin, the bites become raised red bumps over a 24-hour period, as noted by the Illinois Department of Public Health. Fleas do carry bubonic plague and a few cases of the disease turn up every year. The Oriental rat flea, which lives on rats and humans, is a spreader of this disease, according to the Entomology Department at Purdue University.
Sometimes, children accidentally ingest fleas and develop a tapeworm infection from the parasitic eggs inside the flea host.