Antibiotic Allergy Clinical Update

This Clinical Update has been adapted by ASCIA, with permission, from the allergy section of the Therapeutic Guidelines for Antibiotics.

The main purpose of this document is to provide an evidence based, ‘quick reference guide’ to assist primary health care physicians including general practitioners, paediatricians and nurses, in the management of patients with antibiotic allergy. 

pdfASCIA HP Clinical Update Antibiotic Allergy 2014299.35 KB 


Note: Full Introduction and content outline shown. 


While less than 20% of all adverse drug reactions are immune mediated, it is common for a patient to give a history of being 'allergic' to an antimicrobial, usually penicillin. If penicillin is administered to a highly allergic patient, fatal anaphylaxis can occur.

However, it is important to consider:

  • Most patients who report a penicillin allergy have a vague history and are not allergic at all.
  • It is also important not to deny patients treatment with an antimicrobial unnecessarily, especially if they have a serious infection for which that antimicrobial would be the most effective treatment.

Hence, evaluation for drug allergy involves a risk-benefit analysis based on history, allergy test results (where available) and, if indicated, direct challenge under medical supervision.

Risk factors for the clinical expression of antibiotic allergy include:

  • Previous exposure (which may have been non-therapeutic such as in utero or through food products).
  • Aged between 20 and 49 (children and the elderly are at lower risk).
  • Route of administration (e.g. allergic reactions to penicillin occur more frequently following parenteral rather than oral administration).

2. Types of antibiotic hypersensitivity

2.1. IgE-mediated immediate hypersensitivity
2.2. IgE-independent reactions
2.3. Delayed reactions

3. Diagnosis of antibiotic hypersensitivity

3.1. Clinical History
3.2. Skin and blood testing
3.3. Cross reactivity

4. Management of patients reporting penicillin hypersensitivity


Further Information and resources 

Content updated May 2015

Mod ASCIA Member
Donate to AIFA
go to NAC website

ASCIA is the peak professional body of clinical immunology and allergy in Australia and New Zealand
ASCIA promotes and advances the study and knowledge of allergy and other immune diseases

Quick Links


ASCIA is a registered trademark of the Australasian Society of Clinical Immunology and Allergy. All content is subject to copyright for the Australasian Society of Clinical Immunology and Allergy. Read more...

The content for the website is developed and approved by ASCIA Committee and ASCIA Working Party Members. Read more...

Disclaimer I Privacy

The ASCIA website is intended for use by ASCIA members, health professionals and the general public. The content provided is for education, communication and information purposes only and is not intended to replace or constitute medical advice or treatments. Read more...

ASCIA respects your privacy. Read our privacy policy here...

Sponsors | Advertising

ASCIA does not endorse products from sponsoring organisations, nor is it influenced by sponsoring organisations with regard to the content of education programs and websites. 

The ASCIA website does not accept advertising. Any link to a third-party website does not imply any endorsement by ASCIA.

Information Partner

Official Information Partner of Healthdirect Australia