September 28th is National Penicillin Allergy Day

raising awareness on national penicillin allergy day

National Penicillin Allergy Day is on September 28, 2022.

Penicillin is an antibiotic originally obtained from Penicillium molds.  They were some of the first medications to be effective against bacterial infections. Especially those caused by staphylococci and streptococci. They are still widely used today for different bacterial infections.

Although some types of bacteria have developed resistance after extensive use.

The History of Penicillin

Penicillin was discovered in 1928 by Alexander Fleming, a Scottish scientist. His student Cecil George Paine was the first person to use penicillin to treat an eye infection in 1930.

The purified compound was isolated in 1940 by Howard Florey and Ernst Boris Chain at the University of Oxford. Fleming first used the purified penicillin to treat streptococcal meningitis in 1942. In 1945 Fleming shared the Nobel Prize in Physiology or Medicine with Florey and Chain.

Since then, several other forms of penicillin have been developed and are effective against a broader spectrum of bacteria.

Penicillin Allergy

A penicillin allergy is a reaction by your immune system to the antibiotic drug penicillin.

Your immune system is supposed to fight off bacteria that can make you sick. Unfortunately, sometimes your body fights the medicine instead.

That is what happens when you are allergic to Penicillin. Your immune system thinks it’s an invader and tries to get rid of it.

Penicillin Allergy Symptoms

Some signs that you may notice after taking penicillin if you are allergic to it are:

  • Coughing
  • Wheezing
  • Shortness of breath
  • Fever
  • Hives
  • Itchy or watery eyes
  • Swelling
  • Runny nose
  • Anaphylaxis


In some cases, people have a severe reaction called anaphylaxis. In this case call 911 if the following symptoms occur.

  • Belly pain
  • Trouble breathing
  • Diarrhea
  • Seizures
  • Drop in Blood Pressure
  • Weak, rapid pulse
  • Throat or tongue swelling
  • Dizziness or lightheaded
  • Passing out
  • Tightness in chest
  • Throwing up

Delayed Reactions can also occur

Some allergic reactions can happen days or weeks later.  These can include

  • Joint Pain
  • Swelling
  • Rash
  • Feeling nauseous
  • Exhaustion
  • Fever
  • Confusion
  • Blood in urine
  • Serum Sickness which may cause joint pain, rash, swelling, nausea and fever.
  • Drug-induced anemia, a reduction in red blood cells which can cause fatigue, irregular heartbeat, shortness of breath and other symptoms.
  • Drug reaction with eosinophilia and systemic symptoms (DRESS) which may cause rash, high white blood cell count, general swelling, swollen lymph noes and recurrence of dormant hepatitis infection.
  • Stevens-Johnson syndrome or toxic epidermal necrolysis, which involves severe blistering and peeling skin
  • Inflammation in the kidneys (nephritis) which causes fever, blood in the urine, swelling, confusion, and other symptoms.
penicillin is the most commonly reported drug allergy

We have put together a Penicillin Allergy Evaluation – Commonly Asked Questions

Penicillin Allergy Evaluation – Commonly Asked Questions

Penicillin is an effective medication used to treat bacterial infections. Alternative medications used in place of penicillin can put you or your child at greater risk of becoming immune to a stronger medication that could be needed to treat infection in the future.

What is the benefit of having this evaluation?

Having an evaluation for penicillin allergy will help you determine if you or your child is actually at risk for a dangerous reaction or if it would be safe to take this class of medications. If the evaluation is reassuring, you can feel confident about using penicillin in the future.

If the evaluation shows the potential for a dangerous kind of reaction to penicillin allergy, you will know for sure that it has to be avoided.

When will I get the results?

The results of the penicillin allergy evaluation will be known on the same day as your appointment before you even leave the clinic.

lets chat about penicillin allergy testing

How long will the penicillin allergy evaluation take?

The evaluation can take 1½ to 2 hours.

What is involved in the evaluation? Will it hurt?

Depending on the type of reaction you or your child had, the evaluation might include allergy skin testing and/or a penicillin challenge. The allergy skin testing involves a small number of scratch tests (like a sharp fingernail scratching the skin) and intradermal tests (fluid is injected underneath the very top layer of the skin using a tiny needle).

If the allergy skin testing is negative, a dose of penicillin is given in the clinic and you or your child is monitored for 30-60 minutes.

Sometimes, allergy skin testing isn’t needed, especially in children or in adults whose reactions occurred when they were children.

In these situations, a very small dose of penicillin is given by mouth. If after 10-15 minutes, there is no reaction, a full dose of penicillin is given and you or your child are monitored for 30-60 minutes.

What if a severe reaction occurs?

The risk of a severe reaction during evaluation for penicillin allergy is very low. However, penicillin allergy evaluation is only done in the Allergy Clinic where the healthcare providers have a lot of experience with treating severe reactions quickly and effectively.

Does insurance cover the cost of this evaluation?

Most insurance plans cover the cost of penicillin allergy testing. You can check with your specific insurance provider to see what your out-of-pocket costs may be. Please be aware that the codes submitted may vary for each individual patient, depending on what testing is needed.

CPT codes may include: 95018 (6 units) 95024 (2 units) 95004 (2 units) 95076 (1 unit)

When to see a doctor

If you experience any signs or symptoms of penicillin allergy you should see your doctor as soon as possible. It is important to understand what is an allergic reaction, what is a typical side effect and what can you tolerate in taking medication.

Call 911 or emergency medical help if you experience signs of a severe reaction or suspected anaphylaxis.

Learn about your allergy triggers.