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Areas of Expertise

  • Adult Asthma
  • Adult Food Allergy / Anaphylaxis
  • Adult Immunodeficiency (Not HIV)
  • Adult Urticaria / Angioedema
  • Allergy / Immunology
  • Allergy and Immunology
  • Mastocytosis

Conditions and Treatments



  • English
  • Portuguese
  • Spanish


  • Doctor of Medicine - Ohio State University, 1997
  • Internship - Scripps Mercy Hospital, 1998
  • Residency - Scripps Mercy Hospital, 2000
  • Fellowship - Scripps Clinic and Research Foundation, 2002

Patient Comments

Patient Comments are gathered from the Press Ganey Patient Experience Survey and displayed in full. Patients are not identified in order to respect patient privacy.
Dr. Fahrenholz spent more time with me than any provider ever has. He was kind, thorough, answered all my questions at my level of understanding, and really connected with me to give me individualized care. The best clinic experience I have ever had at the scariest time of my life.
May 16, 2024
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I have seen Dr. Fahrenholz for many years. He takes really great care of me. My son accompanies me to clinic now and Dr.. Fahrenholz listens to both of us as he creates his plan of care for me.
January 29, 2024
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John Fahrenholz has always demonstrated a professionalism linked with empathy, care and humor. I find our appointments to be important, and I look forward to them greatly. I feel lucky to be in his care.
January 11, 2024
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Nurse assistant and doctor were very caring and professional
January 8, 2024
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Terrible experience
November 20, 2023
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This doctor actually LISTENED to me.. I felt geard and knew he was trying very hard to figure out my health condition and/or a referral to who could... I hadn't felt heard in a long time...
October 31, 2023
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Dr Faharenholz is wonderful. He listens and explains where the patient can understand.
October 9, 2023
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Dr. Fahrenholz is very caring and concerned.
September 4, 2023
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Doctor spend a lot more time to listen to me.Thank you
August 14, 2023
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