Benzocaine can cause skin irritation, rashes, and more rare side effects like allergic reactions and methemoglobinemia, where there is not enough oxygen in the blood. This topical anesthetic may be prescribed to treat pain and itching associated with a variety of issues. Patients should follow the application directions with care to reduce the risk of overdosing, and may want to discuss any unusual side effects with a doctor to determine if the medication is safe for them to use.
Most commonly, patients who take benzocaine experience some localized skin irritation. They may notice redness or a change in texture, and sometimes experience cracking, flaking, and itching. It should not be applied to open wounds, as this can cause more serious complications. Loss of sensation can also occur, although it may be difficult to distinguish this from the anesthetic effect provided by the medication. Patients who notice extreme skin irritation may want to discontinue use of the drug until they can talk to a doctor.
Some patients have allergic reactions to benzocaine. These patients may develop severe rashes within minutes of application. If the medication is used in a site like the mouth, severe swelling can occur. The patient may have difficulty breathing, chewing, and swallowing as a result of the allergic reaction and could become extremely uncomfortable. Patients with a history of allergic reactions to benzocaine should request an alternative medication to manage pain and itching.
In rare cases, patients develop methemoglobinemia. The low oxygen can cause bluing in the extremities as well as fatigue, dizziness, and confusion. This severe benzocaine side effect may require medical treatment. Patients will need to stop taking the benzocaine and discuss the issue with a doctor to determine which steps, if any, they need to take. The reaction should also be noted to prevent prescriptions of the medication in the future.
If a patient cannot take benzocaine, there are alternatives available. A doctor can discuss the medications on the market with the patient to determine which might be a good choice. Some alternatives are more expensive or do not work as well, and patients may want to consider this when they review their options. For patients with a history of severe reactions, it is advisable to carry a medical alert card with this information. In the event of an emergency, care providers will need the information on the card to know which medications to avoid.