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Meet Rachael Stillwagon

National Commission on Certification of Physician
Assistants, Board Certified, 1998

Rachael Stillwagon, MS, PA-C, is a caring physician assistant at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

Rachael was born in Iowa and raised in Iowa and Wisconsin. She received her Bachelor of Arts in biology and psychology from the University of Iowa.

She then earned her Master of Science in physician assistant studies at Rosalind Franklin University of Medicine and Science (RFU), formerly Finch University of Health Sciences. Rachael practiced internal medicine in Chicago for two years and co-taught a pharmacology class at RFU with her husband, Chad, a pharmacist.

In 2000, Rachael began working in the specialty of allergy and asthma, and has been passionate about the field ever since. In 2002, she and her husband moved to Scottsdale, where she continued her work. Rachael is a member of multiple allergy associations locally and nationally. She has served on various professional committees and currently lectures locally on atopic dermatitis.

As a physician assistant, Rachael serves as a primary care provider within the clinic. Her responsibilities include history and physical examinations, ordering and interpreting diagnostic tests, prescribing medications, and patient follow-ups. She works personally with each patient to formulate a treatment plan and ensure the best possible care.

Rachael and her husband have three children, all born in Scottsdale. She enjoys running, spending time with friends and her large family, volunteering with her children for Boys Team Charity and the National Charity League, as well as various projects at their schools. She loves watching her children participate in their sporting events and other activities!

Meet Dr. Thakrar: 

Hiral Thakrar, MD, is an allergist and immunologist at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

She manages adult and pediatric conditions, such as allergies of the nose and skin, hives, asthma, food allergies, and drug allergies. She is board certified in both Internal Medicine and Allergy and Immunology.

Dr. Thakrar was born and raised in Tanzania, East Africa, and attended the University of California, Los Angeles for her undergraduate studies.

She then pursued her medical degree at Ross University School of Medicine and completed her internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. There, she was the Wellness Chief and participated in the Wellness and Integrative Medicine Committee. She completed her fellowship in allergy and immunology at Scripps Clinic in San Diego, California.

She is a member of the Western Society of Allergy, Asthma & Immunology, American Academy of Allergy, Asthma & Immunology (AAAAI), and American College of Allergy, Asthma, and Immunology. She has been a mentor for future aspiring allergists in medical school and residency for the past two years as a Chrysalis mentor for AAAAI.

Dr. Thakrar has conducted her research in Dupilumab and its effects on patch testing for allergic contact dermatitis, alcohol reactivity in AERD, penicillin allergy, epitope binding, and single sequencing with peanut allergy. Her special interests are asthma, aspirin-exacerbated respiratory disease (AERD), food allergies, and contact dermatitis. She takes an integrative medicine approach to all these diseases.

Dr. Thakrar is also the allergy residency director of two residency programs in East Valley. She mentors current residents and fellows in the field of allergy, asthma & immunology. She isnow also the co-director of wellness for residents at the residency programs. 

Dr. Thakrar is married and loves to spend time with her two beautiful children. In her free time, she enjoys yoga and meditation, traveling, and hiking, and participating in Indian cultural events.

Meet Dr. Davis

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Board-certified in internal medicine, Aaron Davis, MD, is also a board-certified allergist and immunologist. He is dedicated to providing personalized care at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona. He joined Allergy, Asthma & Immunology, LTD, in 2005 and serves as an investigator in clinical research trials.

Dr. Davis was born and raised in Richland, Washington. He graduated from Carroll College in Helena, Montana, with a Bachelor of Arts in biology. He completed medical school at St. Louis University School of Medicine.

Afterward, he moved to Arizona for his internal medicine residency at Mayo Clinic in Scottsdale and completed an allergy and immunology fellowship at Henry Ford Health Systems in Michigan.

He is a member of the Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; American Medical Association; Maricopa County Medical Society; and Arizona Allergy and Asthma Society. Dr. Davis is also a diplomate of the American Board of Internal Medicine and board-eligible by the American Board of Allergy and Immunology.

Dr. Davis is married to Kelly, an orthopedic physician assistant. He enjoys outdoor activities and traveling.

Meet Dr. Manning

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Michael Manning, MD, is board-certified in internal medicine as well as allergy and immunology. He provides a wide range of care to patients at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

An Arizona native, Dr. Manning has very deep roots in the valley. His interest in allergy and immunology started when he was a patient in the office that he eventually joined.

He was very fortunate to start his career under the guidance of his childhood allergist and mentor, Dr. Hartley. This background gives Dr. Manning a unique insight and compassion for his

patients. Dr. Manning graduated with honors from Baylor University in Waco, Texas. He attended the University of Texas Health Science Center at Houston and pursued his internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix. This was followed by an allergy and immunology fellowship at Scripps Clinic and Research Foundation in La Jolla, California.

Dr. Manning is a fellow of the American Academy of Allergy, Asthma, and Immunology and the American College of Allergy, Asthma, and Immunology. He is active on committees and leadership positions in both organizations. He is a diplomate of the American Board of Internal Medicine as well as the American Board of Allergy and Immunology. Dr. Manning is currently a member of the Board of Regents for the American College of Allergy, Asthma, and Immunology. He is a past president of the Western Society of Allergy, Asthma & Immunology.

His expertise includes allergies, asthma, sinusitis, food allergies, drug allergies, angioedema and hereditary angioedema, hives, contact dermatitis, aspirin and other drug desensitization, and immune deficiencies. Dr. Manning lectures throughout the United States, oversees a cutting-edge research department within his practice, and is active in educating medical students, residents, and allergy fellows.

For many years, Dr. Manning coached his sons in various youth sports. He was active on the boards of the different little league and high school sports. He has always had a love for running and enjoys completing half and full marathons with his daughter. He and his wife are also passionate about animal rescue.

Meet Jean Nelson

RN, MSN Certified - ANCC Member of the American
Academy of Nurse Practitioners

Nurse practitioner Jean Nelson, RN, FNP-C, has been working at Allergy, Asthma & Immunology, LTD, for over 30 years. She provides compassionate care to patients at the practice’s two locations in Scottsdale and another in Gilbert, Arizona.

She received her associate’s degree in science and nursing at Iowa Central Community College and her Bachelor of Science in nursing at Arizona State University (ASU). She gained experience working as a registered nurse alongside Drs. Hartley, Romero, and Manning at Allergy, Asthma & Immunology, LTD.

Jean later completed her family nurse practitioner curriculum and her Master of Science at the ASU Edson College of Nursing and Health Innovation. She graduated summa cum laude and was recognized as a Graduate Scholar of the Year in 2003. Her applied research project assessed the management of adult asthma through support and education.

As a family nurse practitioner, Jean serves as a primary care provider within the clinic. She gathers complete histories, performs physical exams, orders and interprets diagnostic tests, prescribes medications, and collaborates with patients to formulate a treatment plan and optimized well-being.

Jean is a patient advocate who focuses on health promotion and wellness with patients. She embraces the value of being proactive rather than reactive in health care planning and management. She enjoys educating not only her patients but also health care providers nationwide. Jean travels extensively throughout the United States lecturing about various diseases and the latest in medical treatments.

She is proud to serve as an active board member of the Arizona Asthma Coalition and is the chairman of the planning committee for the annual Asthma & Allergy Clinical Conference in Phoenix. She is certified by the American Nurses Credentialing Center and a member of the American Academy of Nurse Practitioners.

Jean is the mother of three children and is an accomplished pianist and organist.

Meet Rachael Stillwagon

National Commission on Certification of Physician
Assistants, Board Certified, 1998

Rachael Stillwagon, MS, PA-C, is a caring physician assistant at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

Rachael was born in Iowa and raised in Iowa and Wisconsin. She received her Bachelor of Arts in biology and psychology from the University of Iowa.

She then earned her Master of Science in physician assistant studies at Rosalind Franklin University of Medicine and Science (RFU), formerly Finch University of Health Sciences. Rachael practiced internal medicine in Chicago for two years and co-taught a pharmacology class at RFU with her husband, Chad, a pharmacist.

In 2000, Rachael began working in the specialty of allergy and asthma, and has been passionate about the field ever since. In 2002, she and her husband moved to Scottsdale, where she continued her work. Rachael is a member of multiple allergy associations locally and nationally. She has served on various professional committees and currently lectures locally on atopic dermatitis.

As a physician assistant, Rachael serves as a primary care provider within the clinic. Her responsibilities include history and physical examinations, ordering and interpreting diagnostic tests, prescribing medications, and patient follow-ups. She works personally with each patient to formulate a treatment plan and ensure the best possible care.

Rachael and her husband have three children, all born in Scottsdale. She enjoys running, spending time with friends and her large family, volunteering with her children for Boys Team Charity and the National Charity League, as well as various projects at their schools. She loves watching her children participate in their sporting events and other activities!

Meet Dr. Thakrar: 

Hiral Thakrar, MD, is an allergist and immunologist at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

She manages adult and pediatric conditions, such as allergies of the nose and skin, hives, asthma, food allergies, and drug allergies. She is board certified in both Internal Medicine and Allergy and Immunology.

Dr. Thakrar was born and raised in Tanzania, East Africa, and attended the University of California, Los Angeles for her undergraduate studies.

She then pursued her medical degree at Ross University School of Medicine and completed her internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. There, she was the Wellness Chief and participated in the Wellness and Integrative Medicine Committee. She completed her fellowship in allergy and immunology at Scripps Clinic in San Diego, California.

She is a member of the Western Society of Allergy, Asthma & Immunology, American Academy of Allergy, Asthma & Immunology (AAAAI), and American College of Allergy, Asthma, and Immunology. She has been a mentor for future aspiring allergists in medical school and residency for the past two years as a Chrysalis mentor for AAAAI.

Dr. Thakrar has conducted her research in Dupilumab and its effects on patch testing for allergic contact dermatitis, alcohol reactivity in AERD, penicillin allergy, epitope binding, and single sequencing with peanut allergy. Her special interests are asthma, aspirin-exacerbated respiratory disease (AERD), food allergies, and contact dermatitis. She takes an integrative medicine approach to all these diseases.

Dr. Thakrar is also the allergy residency director of two residency programs in East Valley. She mentors current residents and fellows in the field of allergy, asthma & immunology. She isnow also the co-director of wellness for residents at the residency programs. 

Dr. Thakrar is married and loves to spend time with her two beautiful children. In her free time, she enjoys yoga and meditation, traveling, and hiking, and participating in Indian cultural events.

Meet Dr. Davis

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Board-certified in internal medicine, Aaron Davis, MD, is also a board-certified allergist and immunologist. He is dedicated to providing personalized care at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona. He joined Allergy, Asthma & Immunology, LTD, in 2005 and serves as an investigator in clinical research trials.

Dr. Davis was born and raised in Richland, Washington. He graduated from Carroll College in Helena, Montana, with a Bachelor of Arts in biology. He completed medical school at St. Louis University School of Medicine.

Afterward, he moved to Arizona for his internal medicine residency at Mayo Clinic in Scottsdale and completed an allergy and immunology fellowship at Henry Ford Health Systems in Michigan.

He is a member of the Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; American Medical Association; Maricopa County Medical Society; and Arizona Allergy and Asthma Society. Dr. Davis is also a diplomate of the American Board of Internal Medicine and board-eligible by the American Board of Allergy and Immunology.

Dr. Davis is married to Kelly, an orthopedic physician assistant. He enjoys outdoor activities and traveling.

Meet Dr. Manning

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Michael Manning, MD, is board-certified in internal medicine as well as allergy and immunology. He provides a wide range of care to patients at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

An Arizona native, Dr. Manning has very deep roots in the valley. His interest in allergy and immunology started when he was a patient in the office that he eventually joined.

He was very fortunate to start his career under the guidance of his childhood allergist and mentor, Dr. Hartley. This background gives Dr. Manning a unique insight and compassion for his

patients. Dr. Manning graduated with honors from Baylor University in Waco, Texas. He attended the University of Texas Health Science Center at Houston and pursued his internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix. This was followed by an allergy and immunology fellowship at Scripps Clinic and Research Foundation in La Jolla, California.

Dr. Manning is a fellow of the American Academy of Allergy, Asthma, and Immunology and the American College of Allergy, Asthma, and Immunology. He is active on committees and leadership positions in both organizations. He is a diplomate of the American Board of Internal Medicine as well as the American Board of Allergy and Immunology. Dr. Manning is currently a member of the Board of Regents for the American College of Allergy, Asthma, and Immunology. He is a past president of the Western Society of Allergy, Asthma & Immunology.

His expertise includes allergies, asthma, sinusitis, food allergies, drug allergies, angioedema and hereditary angioedema, hives, contact dermatitis, aspirin and other drug desensitization, and immune deficiencies. Dr. Manning lectures throughout the United States, oversees a cutting-edge research department within his practice, and is active in educating medical students, residents, and allergy fellows.

For many years, Dr. Manning coached his sons in various youth sports. He was active on the boards of the different little league and high school sports. He has always had a love for running and enjoys completing half and full marathons with his daughter. He and his wife are also passionate about animal rescue.

Meet Jean Nelson

RN, MSN Certified - ANCC Member of the American
Academy of Nurse Practitioners

Nurse practitioner Jean Nelson, RN, FNP-C, has been working at Allergy, Asthma & Immunology, LTD, for over 30 years. She provides compassionate care to patients at the practice’s two locations in Scottsdale and another in Gilbert, Arizona.

She received her associate’s degree in science and nursing at Iowa Central Community College and her Bachelor of Science in nursing at Arizona State University (ASU). She gained experience working as a registered nurse alongside Drs. Hartley, Romero, and Manning at Allergy, Asthma & Immunology, LTD.

Jean later completed her family nurse practitioner curriculum and her Master of Science at the ASU Edson College of Nursing and Health Innovation. She graduated summa cum laude and was recognized as a Graduate Scholar of the Year in 2003. Her applied research project assessed the management of adult asthma through support and education.

As a family nurse practitioner, Jean serves as a primary care provider within the clinic. She gathers complete histories, performs physical exams, orders and interprets diagnostic tests, prescribes medications, and collaborates with patients to formulate a treatment plan and optimized well-being.

Jean is a patient advocate who focuses on health promotion and wellness with patients. She embraces the value of being proactive rather than reactive in health care planning and management. She enjoys educating not only her patients but also health care providers nationwide. Jean travels extensively throughout the United States lecturing about various diseases and the latest in medical treatments.

She is proud to serve as an active board member of the Arizona Asthma Coalition and is the chairman of the planning committee for the annual Asthma & Allergy Clinical Conference in Phoenix. She is certified by the American Nurses Credentialing Center and a member of the American Academy of Nurse Practitioners.

Jean is the mother of three children and is an accomplished pianist and organist.

Meet Dr. Thakrar: 

Hiral Thakrar, MD, is an allergist and immunologist at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

She manages adult and pediatric conditions, such as allergies of the nose and skin, hives, asthma, food allergies, and drug allergies. She is board certified in both Internal Medicine and Allergy and Immunology.

Dr. Thakrar was born and raised in Tanzania, East Africa, and attended the University of California, Los Angeles for her undergraduate studies.

She then pursued her medical degree at Ross University School of Medicine and completed her internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. There, she was the Wellness Chief and participated in the Wellness and Integrative Medicine Committee. She completed her fellowship in allergy and immunology at Scripps Clinic in San Diego, California.

She is a member of the Western Society of Allergy, Asthma & Immunology, American Academy of Allergy, Asthma & Immunology (AAAAI), and American College of Allergy, Asthma, and Immunology. She has been a mentor for future aspiring allergists in medical school and residency for the past two years as a Chrysalis mentor for AAAAI.

Dr. Thakrar has conducted her research in Dupilumab and its effects on patch testing for allergic contact dermatitis, alcohol reactivity in AERD, penicillin allergy, epitope binding, and single sequencing with peanut allergy. Her special interests are asthma, aspirin-exacerbated respiratory disease (AERD), food allergies, and contact dermatitis. She takes an integrative medicine approach to all these diseases.

Dr. Thakrar is also the allergy residency director of two residency programs in East Valley. She mentors current residents and fellows in the field of allergy, asthma & immunology. She isnow also the co-director of wellness for residents at the residency programs. 

Dr. Thakrar is married and loves to spend time with her two beautiful children. In her free time, she enjoys yoga and meditation, traveling, and hiking, and participating in Indian cultural events.

Meet Rachael Stillwagon

National Commission on Certification of Physician
Assistants, Board Certified, 1998

Rachael Stillwagon, MS, PA-C, is a caring physician assistant at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

Rachael was born in Iowa and raised in Iowa and Wisconsin. She received her Bachelor of Arts in biology and psychology from the University of Iowa.

She then earned her Master of Science in physician assistant studies at Rosalind Franklin University of Medicine and Science (RFU), formerly Finch University of Health Sciences. Rachael practiced internal medicine in Chicago for two years and co-taught a pharmacology class at RFU with her husband, Chad, a pharmacist.

In 2000, Rachael began working in the specialty of allergy and asthma, and has been passionate about the field ever since. In 2002, she and her husband moved to Scottsdale, where she continued her work. Rachael is a member of multiple allergy associations locally and nationally. She has served on various professional committees and currently lectures locally on atopic dermatitis.

As a physician assistant, Rachael serves as a primary care provider within the clinic. Her responsibilities include history and physical examinations, ordering and interpreting diagnostic tests, prescribing medications, and patient follow-ups. She works personally with each patient to formulate a treatment plan and ensure the best possible care.

Rachael and her husband have three children, all born in Scottsdale. She enjoys running, spending time with friends and her large family, volunteering with her children for Boys Team Charity and the National Charity League, as well as various projects at their schools. She loves watching her children participate in their sporting events and other activities!

Meet Dr. Davis

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Board-certified in internal medicine, Aaron Davis, MD, is also a board-certified allergist and immunologist. He is dedicated to providing personalized care at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona. He joined Allergy, Asthma & Immunology, LTD, in 2005 and serves as an investigator in clinical research trials.

Dr. Davis was born and raised in Richland, Washington. He graduated from Carroll College in Helena, Montana, with a Bachelor of Arts in biology. He completed medical school at St. Louis University School of Medicine.

Afterward, he moved to Arizona for his internal medicine residency at Mayo Clinic in Scottsdale and completed an allergy and immunology fellowship at Henry Ford Health Systems in Michigan.

He is a member of the Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; American Medical Association; Maricopa County Medical Society; and Arizona Allergy and Asthma Society. Dr. Davis is also a diplomate of the American Board of Internal Medicine and board-eligible by the American Board of Allergy and Immunology.

Dr. Davis is married to Kelly, an orthopedic physician assistant. He enjoys outdoor activities and traveling.

Meet Dr. Manning

Diplomate American Board of Internal Medicine,
Diplomate American Board of Allergy and Immunology

Michael Manning, MD, is board-certified in internal medicine as well as allergy and immunology. He provides a wide range of care to patients at Allergy, Asthma & Immunology, LTD, with two locations in Scottsdale and another in Gilbert, Arizona.

An Arizona native, Dr. Manning has very deep roots in the valley. His interest in allergy and immunology started when he was a patient in the office that he eventually joined.

He was very fortunate to start his career under the guidance of his childhood allergist and mentor, Dr. Hartley. This background gives Dr. Manning a unique insight and compassion for his

patients. Dr. Manning graduated with honors from Baylor University in Waco, Texas. He attended the University of Texas Health Science Center at Houston and pursued his internal medicine residency at St. Joseph’s Hospital and Medical Center in Phoenix. This was followed by an allergy and immunology fellowship at Scripps Clinic and Research Foundation in La Jolla, California.

Dr. Manning is a fellow of the American Academy of Allergy, Asthma, and Immunology and the American College of Allergy, Asthma, and Immunology. He is active on committees and leadership positions in both organizations. He is a diplomate of the American Board of Internal Medicine as well as the American Board of Allergy and Immunology. Dr. Manning is currently a member of the Board of Regents for the American College of Allergy, Asthma, and Immunology. He is a past president of the Western Society of Allergy, Asthma & Immunology.

His expertise includes allergies, asthma, sinusitis, food allergies, drug allergies, angioedema and hereditary angioedema, hives, contact dermatitis, aspirin and other drug desensitization, and immune deficiencies. Dr. Manning lectures throughout the United States, oversees a cutting-edge research department within his practice, and is active in educating medical students, residents, and allergy fellows.

For many years, Dr. Manning coached his sons in various youth sports. He was active on the boards of the different little league and high school sports. He has always had a love for running and enjoys completing half and full marathons with his daughter. He and his wife are also passionate about animal rescue.

Meet Jean Nelson

RN, MSN Certified - ANCC Member of the American
Academy of Nurse Practitioners

Nurse practitioner Jean Nelson, RN, FNP-C, has been working at Allergy, Asthma & Immunology, LTD, for over 30 years. She provides compassionate care to patients at the practice’s two locations in Scottsdale and another in Gilbert, Arizona.

She received her associate’s degree in science and nursing at Iowa Central Community College and her Bachelor of Science in nursing at Arizona State University (ASU). She gained experience working as a registered nurse alongside Drs. Hartley, Romero, and Manning at Allergy, Asthma & Immunology, LTD.

Jean later completed her family nurse practitioner curriculum and her Master of Science at the ASU Edson College of Nursing and Health Innovation. She graduated summa cum laude and was recognized as a Graduate Scholar of the Year in 2003. Her applied research project assessed the management of adult asthma through support and education.

As a family nurse practitioner, Jean serves as a primary care provider within the clinic. She gathers complete histories, performs physical exams, orders and interprets diagnostic tests, prescribes medications, and collaborates with patients to formulate a treatment plan and optimized well-being.

Jean is a patient advocate who focuses on health promotion and wellness with patients. She embraces the value of being proactive rather than reactive in health care planning and management. She enjoys educating not only her patients but also health care providers nationwide. Jean travels extensively throughout the United States lecturing about various diseases and the latest in medical treatments.

She is proud to serve as an active board member of the Arizona Asthma Coalition and is the chairman of the planning committee for the annual Asthma & Allergy Clinical Conference in Phoenix. She is certified by the American Nurses Credentialing Center and a member of the American Academy of Nurse Practitioners.

Jean is the mother of three children and is an accomplished pianist and organist.