Most benzocaine side effects are relatively mild and involve skin irritation at the application site. Headaches, increased perspiration, or anxiety may occur among some people using this medication. More serious side effects that should be reported to a doctor for further evaluation include dizziness, changes in the color of the skin, or infection. Rarely, a potentially life-threatening allergic reaction known as anaphylaxis may occur, causing symptoms such as increased heart rate, facial swelling, or difficulty breathing. Any suspected benzocaine side effects should be evaluated by a medical professional to make sure there are no serious complications arising from the use of this drug.
Mild redness and discomfort at the site of application are the most commonly reported benzocaine side effects and usually disappear within a few minutes or hours following the use of this medication. Extreme pain, increased redness, or the formation of blisters may indicate the presence of an allergy and should be reported to a doctor. Occasionally, dry patches of skin that resemble eczema may appear on the affected area as well. These symptoms normally go away on their own following discontinuation of the drug.
Skin infections or discoloration are relatively uncommon benzocaine side effects but require prompt medical attention if they do occur. Topical or oral antibiotics are normally used to clear up any infections that develop as a result of benzocaine use. Any skin discoloration should be evaluated by a physician to make sure there are no serious complications such as reduced circulation at the affected area. Symptoms such as headache or dizziness are usually mild, but if these side effects persist or worsen, a doctor should be notified.
Seizures, changes in heart rhythm, or extreme nausea are possible benzocaine side effects. Abdominal cramping, diarrhea, or vomiting should be medically evaluated, especially if accompanied by a fever. Black or bloody stool or vomit that resembles coffee grounds should prompt a visit to the nearest hospital to rule out the presence of severe gastrointestinal damage.
Anaphylaxis is among the most dangerous possible benzocaine side effects and can cause death within a matter of minutes without emergency medical assistance. Chest pain, difficulty breathing, and loss of consciousness, even for just a few seconds, are potential signs of anaphylaxis. Facial swelling, especially involving the tongue or throat, can cause permanent damage to the brain and other organs of the body due to a lack of oxygen in the bloodstream.