New Location: We've moved! Uptown Allergy & Asthma is now seeing patients at our new location at 2620 Jena Street (right next door to our old location!). We look forward to seeing you in our new space.
Avoiding Penicillins? You Might Not Have To
Penicillin Allergy Testing in New Orleans
Dr. Reena Mehta is a board-certified penicillin allergy specialist in New Orleans that provides penicillin allergy testing. Find out for sure if you can safely take penicillin!
“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
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.
Allergic reactions to penicillin can be immediate (acute-onset) upon intake or occur hours or days later (delayed-onset). They 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

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.

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 undergo penicillin allergy testing. [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 symptoms of penicillin allergy 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.
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.

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.
Penicillin allergy testing is safe to do on everyone, including pregnant women and children.
References
[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
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.
Book Online
Click Here to Book Online
Put time on our calendar. Schedule an appointment using our online booking page.
Email us or use the
contact form below and we'll coordinate your visit.
You can also use this contact form for general inquiries.
Site Navigation
Patient Education

Social Media
Copyright © 2023 by OnChart - All Rights Reserved. Please review our Terms of Use.