Medical Expertise of Dr. Zachary Marshall, MD
Dr. Zachary Marshall is a board-certified Houston allergist and internist providing care to patients of all ages for a variety of allergic and immunologic conditions.
Dr. Marshall’s clinical interests include rhinitis, asthma, environmental allergies, food and drug allergies, hives, eczema, and immune disorders. Dr. Marshall also has a particular interest in the medical humanities and has written on the importance of the doctor-patient relationship
Patient Education Resources
Inhaled corticosteroids (ICS) are a type of medication that is commonly used to treat asthma and other respiratory conditions. They are considered safe because they are delivered directly to the lungs...
There is some evidence to suggest that gluten, a protein found in wheat, barley, and rye, may be a trigger for asthma symptoms in some individuals. However, the relationship between gluten and asthma ...
Biologics are a class of medications that can be used to treat eczema, a chronic skin condition characterized by inflammation and itching. Biologics work by targeting specific parts of the immune syst...
Allergy shots, also known as immunotherapy, is a treatment that can help to reduce the severity of allergic reactions by gradually exposing the body to increasing amounts of the allergen over time. Th...
The treatment of childhood asthma is similar to that of adult asthma, but there are some important considerations.The main goal of treatment is to control symptoms, prevent exacerbations and improve t...
Education & Training
A native Texan, Dr. Marshall graduated from Rice University, the University of Texas Medical School in Houston, and Baylor College of Medicine, where he completed his internal medicine residency and clinical postdoctoral fellowship in allergy and immunology. His fellowship research focused on fungal inflammation of the airway and in vivo models of drug allergy.
McGovern Allergy and Asthma Clinic

“Founded in 1956, Houston’s McGovern Allergy and Asthma Clinic, P.A. has developed a worldwide reputation for excellence in patient care, research, and physician education.” -MD News Magazine
McGovern Allergy and Asthma Clinic providers specialize in the diagnosis and treatment of allergic diseases in adults and children caused by a broad spectrum of allergens. Allergens are substances in the environment that may cause allergic reactions. Such substances may include inhalants, such as house dust mites, mold spores, animal dander or various pollen; ingestants such as food or drugs; injectants such as insect stings; or contactants such as poison ivy, or metal alloys found in some jewelry, or even chemicals in the workplace. Reactions to these allergens may include hay fever, sinus conditions, asthma; skin rashes such as hives or eczema; gastrointestinal problems, or, in extreme cases, anaphylactic shock.
Preventive Care
A main focal point of McGovern Allergy and Asthma Clinic’s health care approach is preventive care. Once a diagnosis has been made, we can teach our patients strategies for avoiding known allergens.
Self Care
We also emphasize self-care. If allergens cannot be avoided, we teach our patients how to treat allergy flare-ups with safe symptomatic medications, such as inhalers for asthma patients. We also teach our patients what to do in the event of emergencies such as insect stings.