About Us

Credentials and Profiles of Our Practitioners

Dr James Yun


Consultant Physician, Immunology & Allergy

Staff Specialist
Nepean Hospital
Visiting Medical Officer
North Shore Private Hospital, St Leonards
Northern Beaches Hospital, Frenchs Forest
Norwest Private Hospital, Bella Vista
Clinical Senior Lecturer
The University of Sydney
Conjoint Senior Lecturer
Western Sydney University

Dr James Yun is a consultant physician in allergy, clinical immunology and immunopathology. He manages allergic disorders in both children (children of all ages) and adults, and immunological conditions in adults. 

Dr Yun obtained his medical degree from the University of Melbourne in 2003 and completed his fellowship with the Royal Australasian College of Physicians and the Royal College of Pathologists of Australasia in 2012. In 2013, he completed his PhD in drug allergy at the University of Bern, Switzerland, under the supervision of Prof. Werner Pichler, a world-renowned scholar in this field. He has been working as a consultant physician in allergy and immunology since returning to Sydney in 2013. He was a staff specialist at Royal North Shore Hospital between 2015 and 2018, and is currently at Nepean Hospital. Dr Yun also has admission rights at North Shore Private Hospital, Northern Beaches Hospital and Norwest Private Hospital.

Dr Yun is a clinical senior lecturer at the University of Sydney and a conjoint senior lecturer at Western Sydney University, and is active in teaching medical students and trainee doctors. He continues to pursue research interest in both food allergy and drug allergy at the University of Sydney. Dr Yun has published extensively in peer-reviewed journals, has given presentations at several international meetings and is regularly invited to review articles for journals. 

Dr Yun is a member of Australasian Society of Clinical Immunology & Allergy, Australian and New Zealand Anaesthetic Allergy Group and European Academy of Allergy & Clinical Immunology.

Dr Yun genuinely cares for his patients and is committed to providing the best possible service. His service includes comprehensive consultation, allergy skin tests, immunotherapy and supervised challenges to both food and drugs. 

Dr Yun's Publications and Presentations:
(please click the above link)
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Dr Fenfen Cai


Consultant Physician, Immunology & Allergy

Clinical Immunology & Allergy Consultant
Northern Beaches Immunology & Allergy
Visiting Medical Officer
Northern Beaches Hospital, Frenchs Forest

Dr Fenfen Cai is a clinical immunologist and allergist. She completed her Bachelor of Medicine at the University of New South Wales and her advanced training in Clinical Immunology and Allergy at Royal North Shore Hospital, St Vincent’s Hospital and Westmead Hospital. Dr Cai has built her experience in allergy, clinical immunology and oral immunology with well-respected immunologists and allergists in large tertiary teaching hospitals. She has authored and co-authors papers in peer-reviewed journals. She also presented presentations at Annual Conference of the Australasian Society of Clinical Immunology and Allergy, Path Update and other scientific meetings.


Dr Cai recognises that many patients have significantly compromised quality of life due to allergy or autoimmune issues. She is passionate about helping patients seek answers and getting on top of their problems using the latest evidence-based medical care. She is compassionate and believes in listening to the patient and building a partnership with the patient in their health journey.


Dr Cai is a member of Australasian Society of Clinical Immunology & Allergy. She is a fluent Chinese mandarin speaker. She has a deep understanding and sensitivity towards patients from a broad ethnic diversity. 

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Katrina Baldwin


Registered Nurse, Oncology & Immunology

Practice Nurse
Northern Beaches Immunology & Allergy

Registered Nurse

Oncology and Infusions Centre

Northern Beaches Hospital

Katrina is a dedicated practice nurse at the Northern Beaches Immunology and Allergy. She works with Dr. James Yun to deliver safe clinical care in allergy challenges, allergy testing and immunotherapy for allergic conditions. Her nursing practice includes both children and adults, and she enjoys developing therapeutic rapport with individuals and families. 


Katrina obtained her Bachelor of Nursing degree from the University of Central Queensland in 2016. She completed rotations in Cardiac and Intensive Care during her graduate year at Prince of Wales Private Hospital before moving to Manly Hospital where she worked on the Surgical ward. When Manly Hospital closed, she transferred to Northern Beaches Hospital to work in the Day of Surgery Centre. Katrina currently works in the Oncology and Infusion Centre at Northern Beaches Hospital. She also works with the Oncologists as a Clinic Nurse.


Katrina is currently studying her Graduate Certificate in Oncology Nursing through the University of Tasmania. As a member of the Cancer Nurses Society of Australia, Katrina is committed to utilising the latest research evidence to inform her clinical practice. She has ongoing specialty interests in both Allergy/Immunology and Oncology.