Infection from flea bites can occur because of scratching the bites. Fleas can transmit a number of diseases, including plague (Yersinia pestis), bartonellosis, typhus (Rickettsia typhi), tungiasis, and flea tapeworm.

What happens when you scratch a flea bite?

You may experience hives or develop a rash near the site of a bite. Scratching a lot can further damage the skin and potentially cause a bacterial infection in the area of the bite. Avoid scratching if you can. Monitor your bites for signs of an infection, including white-topped blisters or a rash.

Does scratching flea bites make them worse?

The skin may become irritated and painful around the bite, and sometimes hives and a rash will appear. Scratching the bite can cause a secondary infection.