Department of Medicine

University of Pittsburgh

Division of Pulmonary, Allergy, and Critical Care Medicine
3459 Fifth Avenue,
628 NW
Pittsburgh, PA 15213
Academic Office: (412) 692-2210
Comprehensive Lung Center (Patient Care and Referral): (412) 648-6161

Merritt Fajt, MD

Assistant Professor of Medicine
UPMC Montefiore Hospital - NW628
3459 Fifth Avenue
Pittsburgh, PA 15213

Academic office: 412-864-2615
Patient appointments: 412-648-6161
Fax: 412-605-1999

Assistant: Emily Stilwell
Assistant Email:


Dr. Merritt Fajt completed her undergraduate education at Duke University in Durham, NC where she earned a Bachelor of science in Biology and graduated cum laude in 2000.  She then attended medical school at Temple University School of Medicine in Philadelphia, PA and graduated in May 2004. This was followed by Internal Medicine Residency training at the Pennsylvania State University Milton S. Hershey Medical Center in Hershey, PA which she completed in June 2007. She then began her fellowship in Allergy-Immunology at the University of Pittsburgh Medical Center which she completed in June 2010.  Dr. Fajt is board certified in Allergy and Clinical Immunology and Internal Medicine.

During her fellowship she also began conducting translational research under the direction of Dr. Sally Wenzel.  She was supported by a T32 training grant during her 3rd year of fellowship and  also an NIH Ruth L. Kirschstein National Research Service Award F32 grant during her fellowship.  She is currently an Assistant Professor of Medicine at the University of Pittsburgh Asthma Institute at the University of Pittsburgh Medical Center/ University of Pittsburgh School of Medicine.

Clinical Interests

Dr. Fajt’s clinical interests include caring for patients with asthma, environmental, food or drug allergies and immunologic disorders.  She sees patients during outpatient allergy-immunology clinic at the Comprehensive Lung Center and inpatient consults.

Academic and Research Interests

Dr. Fajt’s research over the last several years has focused on the pathobiologic mechanisms of severe asthma and the role of mast cells.  While mast cells have been reported in the epithelium, both in the GI tract and in the airway, very little is known regarding the epithelial (and even luminal) mast cells, their phenotype and function in asthma and severe asthma.   Dr. Fajt’s research interest involves determining the location, phenotype and function of airway mast cells in severe asthma, as compared to milder asthma and normal control subjects. She conducts studies from a range of sources including endobronchial biopsy, epithelial cells, bronchoalveolar lavage fluid, sputum, and blood samples. Preliminary data strongly suggest that mast cells in severe asthma, rather than being absent, are actually of an altered functional phenotype and directed towards a luminal location. Her studies will continue to focus on the differences in mast cell phenotypes and their modification by epithelial or luminal factors as it relates to the inflammatory and repair processes of asthma. An understanding of the pathobiology of mast cells in severe asthma could lead to new clinical biomarkers and therapeutic targets.  Dr. Fajt has presented her data at several national conferences. She was a second author on a paper recently accepted to the American Journal of Critical Care Medicine regarding the role of mast cells in severe asthma.

Dr. Fajt also participates in medical education.  She actively participates in journal club and case conferences with the allergy-immunology fellows and gives monthly lectures to the residents in the medical intensive care unit. She has also served as a small group facilitator for medical students. Through her work in the Asthma Institute, she enjoys participating in various community outreach programs.

Key Publications

Fajt ML, Gelhaus SL, Freeman B, Uvalle CE, Trudeau JB, Holguin F, Wenzel SE.  Prostaglandin D₂ pathway upregulation: relation to asthma severity, control, and TH2 inflammation. J Allergy Clin Immunol. 2013 June; 131(6):1504-12.

Fajt ML, Wenzel SE.  Mast cells, their subtypes and relation to asthma phenotypes. Ann Am Thorac Soc 2013 Dec;10 Suppl:S158-64.

Balzar S, Fajt M, Comhair S, Erzurum S, Bleecker E, Busse W, Castro M, Gaston B, Israel E, Schwartz LB, Curran-Everett D, Moore C, Wenzel SE. Phenotype, location and activation of mast cells in severe asthma.   Data from the Severe Asthma Research Program. Am J Resp Crit Care Med 2011 Feb;183:299-309. 

Fajt ML, Wenzel SE. Asthma phenotypes in adults and clinical implications. Expert Rev Resp Med. 2009 Dec; 3(6), 607-625.

Traister RS, Fajt ML, Whitman-Purves E, Anderson WC, Petrov AA. A retrospective analysis comparing subjects with isolated and coexistent vocal cord dysfunction and asthma. Allergy Asthma Proc. 2013 Jul-Aug;34(4):349-55.

Fajt M, Petrov A.  Outpatient Aspirin Desensitization for Patients with Aspirin Hypersensitivity and Cardiac Disease.  Crit Pathw Cardiol  2011 Mar; 10(1)17-21.

Bray S, Fajt ML, Petrov A.  Successful treatment of exercise-induced anaphylaxis with omalizumab.  Ann Allergy Asthma Immunol  2012 Oct; 109(4) 281-2.

PubMed Link