Flea bites are mainly manifested as edematous pemphigoid, which may cause significant redness and swelling over time, and the redness will produce petechiae on the top of the pemphigoid, which is the site of the flea bite. As the skin damage continues to develop, small blisters may be produced on the top of the papules, and if the blisters continue to develop, they may form large blisters and even cause epidermal erosions.