Among the more common biting and sometimes bloodsucking insects in the United States are the following:
None is venomous. The bites of these insects may be irritating because of the components of their saliva. Most bites result in nothing more than a small, red, itchy bump. Sometimes, people develop a large sore (ulcer), with swelling and pain. The most severe reactions occur in people who are allergic to the bites or who develop an infection after being bitten. Fleas can cause allergic reactions sometimes without biting.
The bite should be cleaned, and an ointment or cream containing an antihistamine, an anesthetic, a corticosteroid, or a combination may be applied to relieve itching, pain, and inflammation. People with multiple bites can take an antihistamine by mouth. People who are allergic to the bite should seek medical attention immediately or use an emergency allergy kit containing a preloaded syringe of epinephrine.
Last full review/revision February 2009 by Robert A. Barish, MD, MBA