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Avoiding Penicillins? Get A Test First!

Get A Penicillin Allergy Test in New Orleans

Dr. Reena Mehta is a board-certified penicillin allergy specialist in New Orleans that provides penicillin allergy testing. Learn about penicillin allergies, adverse reactions to penicillin, and why testing for a penicillin allergy is recommended if you suspect an allergy. Contact us for a penicillin allergy test today!

I sought out Dr Mehta for allergy testing this spring, and I’m so glad I did. I had been told since childhood that I had allergies to two fairly common medicines, and I wanted to know whether these assumptions were still true (I’m now in my early 30s). Thanks to Dr. Mehta, I have definitive proof that I have grown out of both allergies and can safely take these medications. my experience at Uptown Allergy & Asthma has been one of the most positive medical experiences I’ve had in New Orleans to date, and I would wholeheartedly recommend Dr Mehta and her staff to anyone and everyone.

– Hope K, July 2019

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Penicillin allergy testing specialist Dr. Reena Mehta in New Orleans, LA
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Penicillin Allergy Overview


Penicillin Allergy vs Adverse Reactions

Penicillin Allergy Testing

Penicillin is one of the most commonly used antibiotics. It is the medicine of choice for many common bacterial illnesses, such as ear infections, sinus infections, tonsillitis, and strep throat. It is also used to prevent bacterial infections in a hospital setting and surgical site infections following an operation.

Prescription penicillin is usually taken orally in the form of amoxicillin, amoxicillin-clavulanate, or penicillin. Other common forms of penicillin include piperacillin-tazobactam, penicillin G, and ampicillin. [2]

A penicillin allergy reaction can be immediate (acute-onset) upon intake or occur hours or days later (delayed-onset). A penicillin allergy reaction tend to present in one of four forms:

  • Delayed-onset rash characterized by small red bumps
  • Delayed-onset severe rash or anaphylaxis
  • Acute-onset hives (also called urticaria)
  • Acute-onset anaphylaxis
Physician holding drugs that may cause penicillin allergies

Penicillin Allergy vs Adverse Reactions

With how common penicillin use is, adverse reactions are relatively common as well. Every time a penicillin course is prescribed, there is a 1% to 2% chance of an adverse reaction occurring. Many of these adverse reactions are mistakenly designated as penicillin allergies without proper allergy testing, while only about 5% of these reactions are actually allergy-related. [2]

Penicillin-Associated Adverse Reactions

Common side effects of penicillin include stomach ache, headache, nausea, vomiting, yeast infection, and rash. There is some overlap in presentation between allergic reactions and adverse reactions to penicillin, so it’s understandable that even trained medical professionals can confuse one for the other.

Male adult scratching rash from penicillin allergy or adverse reaction that needs to be tested

Penicillin Allergy Misdiagnosis is Extremely Common

Penicillin allergy is often estimated to affect 7% to 10% of the general population and up to 20% of hospitalized patients. However, the overwhelming majority of patients do not test positive for penicillin allergies, and most patients do not get a penicillin allergy test. [1] The most recent studies show that only about 1.5% of tested individuals are positive for penicillin allergy, [2] meaning that about 9 out of 10 patients that report a history of penicillin allergy aren’t actually allergic and can receive penicillins safely. [1]

All of that said, it’s important to get tested before starting a penicillin course if you’ve been diagnosed or have exhibited penicillin allergy symptoms in the past.

Risk of Penicillin Avoidance

An incorrectly assumed or misdiagnosed penicillin allergy can have serious consequences, including:

In childhood illnesses – many childhood illnesses including ear infection, strep throat, and pneumonia require a penicillin as a first-line agent.

When having an operation – penicillin is the drug of choice when it comes to preventing surgical site infections. Surgical site infections are more common when penicillin is not used. [2]

When hospitalized – penicillin allergy is more commonly reported in a hospital setting. Patients that report a penicillin allergy are given alternative antibiotics to prevent severe illnesses. Alternatives tend to be slightly less effective than penicillin, and have a higher likelihood of developing resistant bacteria. [1]

Dr. Mehta explain penicillin allergy on Fox 8 Local First News.


Penicillin Allergy Testing

Standardized penicillin allergy testing has been developed to reliably determine whether or not you’re allergic to penicillin. Testing begins with a detailed review of your medical history, with an emphasis on the adverse reactions that you’ve experienced with penicillin use. Skin testing is typically used as a first-line, low-risk testing method to determine if it’s safe for you to try to take a small amount of penicillin by mouth.

If you react to the skin test, your penicillin allergy is confirmed, and you do not need to undergo an oral challenge. If you do not react to the skin test, oral penicillin intake is required to definitively confirm or refute your penicillin allergy.

The entire penicillin allergy testing process takes about 30 minutes to an hour, and typically requires a follow up around 5 days later to confirm that you did not have a delayed response.

Penicillin allergy testing skin test

Who Should Get Tested for Penicillin Allergy?

Patient care decisions are heavily influenced by the medical history provided by the patient and other healthcare professionals. An incorrect penicillin allergy diagnosis can have a major influence on the treatments available to you for common illnesses, and how you’re cared for in a hospital or surgical setting.

If you’ve received a penicillin allergy diagnosis but haven’t been formally tested for your penicillin allergy with a skin test or oral challenge, you should be evaluated by drug allergy specialist to confirm your diagnosis. On the other hand, if you suspect that you have a penicillin allergy due to a history of penicillin-associated rash, gastrointestinal symptoms, stomach aches, headaches, or other symptoms, you can safely undergo testing to determine whether or not your reaction was allergy-related.

A penicillin allergy test is safe to do on everyone, including pregnant women and children.


[1] Lang, D. M., Castells, M. C., Khan, D. A., Macy, E. M., & Murphy, A. W. (2017). Penicillin Allergy Testing Should Be Performed Routinely in Patients with Self-Reported Penicillin Allergy. Journal of Allergy and Clinical Immunology: In Practice, 5(2), 333–334
[2] Macy, E., & Vyles, D. (2018). Who needs penicillin allergy testing? Annals of Allergy, Asthma and Immunology, 121(5), 523–529

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Penicillin Allergy Testing in New Orleans

Avoiding penicillins? You might not have to! Get a formal penicillin allergy diagnosis from a trusted allergist. Dr. Mehta has a reputation for developing strong relationships with her patients and being exceptionally attentive to their needs and concerns.

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(504) 605-5351

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Uptown New Orleans

2620 Jena St,
New Orleans, LA 70115

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