What Is a PCN Allergy?

Penicillin allergy, commonly referred to as PCN or PEN allergy, is a common medication allergy. Penicillin is the most common antibiotic prescribed for bacterial infections. According to Mayo Clinic, “Penicillin allergy is an overreaction by your immune system to penicillin and related antibiotics.”

Mild Reaction

• An allergic reaction to penicillin can produce mild to life-threatening symptoms. Symptoms of a mild reaction include itchy skin, hives and angioedema (swelling of the lips, face or tongue), according to Mayo Clinic.

Life-Threatening Reaction

• An anaphylactic (life-threatening) reaction typically develops within minutes of penicillin exposure. Mayo Clinic notes that the symptoms of a life-threatening reaction to penicillin include difficulty breathing, wheezing, dizziness, low blood pressure and swelling of the throat.

Risk

• You may be at higher risk for penicillin allergy if you have been diagnosed as having HIV or cystic fibrosis.

Diagnosis

• Diagnosis of penicillin allergy is typically determined by your healthcare provider, who may administer a skin test. A skin test consists of injecting penicillin into an individual and watching for signs of a penicillin reaction.

Treatment

• Treatment for penicillin anaphylaxis includes an injection of adrenaline. According to Medline Plus, epinephrine (adrenaline) helps maintain your vital signs and regulate your breathing. For a mild reaction, such as hives, an antihistamine may be recommended.