Subspecialist Spotlight: Dr. Jon Witonsky Tackles the Challenges of Childhood Asthma

What drives a physician to dedicate their career to unraveling the complexities of childhood asthma and allergies?

For Jonathan Witonsky, MD, MAS, Assistant Professor of Pediatrics in the Division of Allergy, Immunology, and Bone Marrow Transplantation, it’s a combination of scientific curiosity, a deep commitment to health equity, and firsthand experiences seeing how a child’s environment can shape their health outcomes.

Witonsky’s dedication to advancing child health led him to complete his residency and fellowship with the Department of Pediatrics at UC San Francisco. He now leads impactful research aimed at reducing health disparities in asthma and ensuring every affected child can reach their full potential.

Read our Q&A with Witonsky to learn about his scientific journey, cutting-edge research, and what drew him to UCSF.

What inspired you to pursue a career in pediatrics? And specifically pediatric allergy and immunology?

I knew before med school that I wanted to go into pediatrics because I loved the idea of making early-life interventions that could have a lifelong impact. Pediatricians also have unique opportunities to help shape a child’s emotional and social well-being during impressionable years.

My interest in allergy and immunology clicked during med school when I learned about the immune system’s incredible adaptability—how a finite genome can recognize infinite pathogens blew me away. Clinically, the field stood out because it combines caring for common conditions, like asthma and allergies, with rarer ones, like inborn errors of immunity. I also love that it spans multiple organ systems, from the respiratory system in asthma to the skin in atopic dermatitis and the digestive tract in food allergies.

What issues in child health do you hope to address in your work?

I focus on tackling disparities in childhood asthma and allergic diseases, especially in populations that are disproportionately impacted by these conditions. My work combines clinical, genomic, and socioenvironmental data to better understand and predict asthma and allergy outcomes.

By using this data to identify at-risk children as early as possible, I hope to create targeted interventions that not only improve how we manage these diseases but also help prevent them from developing in the first place. Ultimately, I aim to develop precision-based interventions that improve asthma outcomes and address the root causes of health disparities.

What is one experience you had during training that reinforced your choice to become a pediatric subspecialist?

During training, an experience that deeply reinforced my path was caring for a child with very severe, uncontrolled asthma. Despite multiple ICU admissions and even being intubated, what struck me most wasn’t just the clinical severity—it was the systemic barriers his family faced: unstable housing, obstacles to obtaining and properly administering his medications, and socioeconomic challenges that made managing his health feel insurmountable.

That experience stayed with me as a powerful reminder that asthma—despite its well-recognized genetic component—is far from being solely about genetics; it reflects the environments we grow up in and how those environments interact with our genes.

 

What attracted you to UCSF for training? 

My interest in the intersection of genetics and health began with my first job after college at the National Human Genome Research Institute. Exploring this further in medical school at the Albert Einstein College of Medicine led me to Dr. John Greally’s lab, where I gained valuable bench experience and was introduced to the UCSF Asthma Collaboratory.

Working with the Collaboratory as a medical student, I studied how genes and the environment drive asthma disparities in children. It was a perfect fit for my interests and goals, and UCSF’s emphasis on collaboration and innovation made it the ideal place to pursue further training. I attended residency at the UCSF Department of Pediatrics and haven’t looked back.

What role has mentorship played in your pediatric journey?

The UCSF Asthma Collaboratory welcomed me into its multidisciplinary team of clinicians, epidemiologists, geneticists, informaticians, and study coordinators, providing me with foundational skills I still rely on today. Dr. Esteban Burchard, the lab’s Principal Investigator, was instrumental in shaping my research mission and vision. Together, we developed a “10-year plan” that integrated clinical training in pediatrics and allergy/immunology with research training in clinical pharmacology, biostatistics, and epidemiology.

Dr. Burchard gave me access to the world’s most extensive datasets on Black and Latino children with and without asthma, guiding me as I conducted studies that laid the foundation of my research career and led to funding as an American Lung Association and NIH-supported early-career investigator.

As faculty, what advantages does UCSF offer for your work? 

In addition to the host of research mentors Dr. Burchard introduced me to, UCSF offers the unparalleled advantage of my clinical colleagues. The experts in the Division of Pediatric Allergy, Immunology, and Bone Marrow Transplantation offer invaluable guidance on complex clinical cases, especially in areas where research is still evolving.

UCSF also provides exceptional resources, such as the UCSF Clinical & Translational Science Institute, which have been instrumental in helping me grow as an independent investigator and conduct impactful research. The combination of mentorship, collaboration, and institutional support makes UCSF an extraordinary place to conduct research and care for patients.

What advice do you have for aspiring pediatricians, especially those interested in pediatric allergy and immunology?

Stay curious, humble, and compassionate. This field is dynamic and multidisciplinary, so take advantage of every opportunity to explore it. Colleagues and mentors are eager to help you grow, so don’t hesitate to reach out. And most importantly, our patients, whether dealing with common allergies or rare immune disorders, need someone who listens, cares, and is committed to finding the best solutions for them.