What Is Penicillin Allergy and How Is It Treated?
Penicillin has been an essential medicine for clearing up bacterial infections for more than seventy years now. However, in some cases, your body may develop allergy to medications, and this drug may also be causing bad reactions in some people using it.
The task of your immune system is to defend you from pathogenic bacteria (the bacteria that cause infection). In some cases, your immune system may mistake medications like penicillin for the bacteria, thinking it’s an invader, and fight it off. This means you have an allergy to penicillin.
This type of antibiotic allergy can develop in anyone; however, the chances are higher in people that are allergic to other medicines and to other substances, have HIV or Epstein-Barr (a herpes virus), or whose family members are penicillin-intolerant.
People who do not fall into these categories may also experience negative side effects of penicillin, if they have been taking it frequently, for long time or in high doses.
Different antibiotics should be used for particular sicknesses, and doctors have to select the right medicine for each case. This is harder with patients allergic to penicillin. If you notice some problems, you can get tested to see what is causing them.
Symptoms of Penicillin Allergy
People who are not tolerant to penicillin usually develop the symptoms within an hour since taking the medicine. The signs are: coughing, wheezing, shortness of breath, fever, hives, itchy and/or watery eyes, itchiness, runny nose, swelling of the skin, and tightness in the throat.
Although it is quite rare, sometimes people may experience a severe reaction such as anaphylaxis. Other serious symptoms include pain in the belly area, difficulty breathing, diarrhea, dizziness or light-headedness, difficulty keeping conscious, seizures, swelling of throat or tongue. If you or someone near you experiences these symptoms, you should call 911.
Sometimes, not very commonly, allergic reaction occurs after days or even weeks from penicillin intake. Thus, you may have swelling, rash, fever, slow heartbeat, you may feel like you are going to vomit, get very exhausted, feel confused, there may be blood in you pee, your joints may hurt.
What Is an Allergy Test?
In order to determine whether you have an allergy, you need to visit a doctor who will make certain examinations, including questions about your symptoms, and probably a skin test or a challenge test.
The most commonly used kind of allergy test is skin test that last for about an hour.
During the first part of the skin test, the doctor pricks your forearm with a tiny needle, that barely breaks you skin surface, and gives you a small dose of penicillin. In about 15 minutes since the procedure, patients allergic to the medicine develop an itchy red bump that reminds a mosquito bite.
In case a bump does not appear, the following step is to insert a dose of penicillin under the skin of your forearm. If you are allergic to penicillin, you will get a bump after 15 minutes. If not, you are unlikely to be allergic.
The last (and optional) part of the skin test is to give you a regular penicillin dose by mouth. The test last for about an hour. If you do not experience any symptoms caused by the medicine during this time, your doctor concludes that you are not allergic to it.
Challenge tests are usually done in patients who actually need penicillin for their treatment but didn’t have a skin test.
This test implies giving you the full dose of the medicine little by little. First, you are given a small dose. If you don’t experience any reactions after half an hour or an hour, then you will be given another dose. To reach the full dose of penicillin, you will take about four to five smaller doses every 30 to 60 minutes, where each dose is higher than the previous.
If there are no symptoms after you took the full dose, you are not allergic to penicillin.
How Can It Be Treated?
If you notice allergic symptoms after taking penicillin, you need to stop taking this medicine. You should see a doctor, and he will prescribe you some antihistamine, like diphenhydramine, which will help with the symptoms. If your symptoms are serious (for example, if you have swelling), you may be given a corticosteroid.
In case of anaphylaxis, you will be immediately given a medication called epinephrine, after which you will spend some time in the hospital until your blood pressure and breathing get back to normal.
What to Do If You Have an Allergy?
People allergic to penicillin should avoid this medicine. You will need to discuss your other antibiotic options with your doctor.
If penicillin is really the only thing that can help, there is a treatment method called desensitization. This method applies to patients who did not have an anaphylactic reaction previously.
Desensitization involves giving you penicillin starting with a small dosage. If after 15 or 30 minutes the allergy symptoms do not occur, you are given a higher dose. Increased doses are given after a few hours or days. Patients who do not develop the symptoms can continue taking penicillin.