Pediatric dermatologist Patrick McMahon, MD, has a genuine love for the doctor-patient relationship. It gives him the opportunity to consult with families every day. In his work, he strives to understand the needs and concerns of patients and families so that he can tailor his advice and treatments to them. Dr. McMahon’s approach takes patience and compassion. “Even the most common conditions need careful consideration when we aim to personalize the care for each patient," he explains.

Dr. McMahon knew he wanted to become a doctor at a very young age. He trained at CHOP in general pediatrics. During his internship, he spent time working in pediatric dermatology, where he fell in love with the work. He loves the detective-like nature of figuring out a challenging diagnosis.

“It is so gratifying to crack the code and get to the bottom of a mystery rash or a peculiar skin lesion,” says Dr. McMahon. “Helping the families and patients who may have been struggling and searching for an answer feels great!”

Dr. McMahon has seen great promise in the use of targeted therapies for common skin conditions. These therapies are improving the ability of doctors to treat severe cases of eczema and psoriasis.

Gene testing can also help doctors understand the cause of many skin, hair and nail disorders. And Dr. McMahon believes telemedicine can improve the way doctors treat dermatology patients.

Dr. McMahon is Medical Director of Teledermatology at CHOP. This new service, called MyDerm E-Visits, is available on MyCHOP. It allows patients to consult with CHOP dermatology doctors online. Patients can send high-quality photographs from smart phones. It is an easy, affordable and convenient way to reach doctors faster.

Dr. McMahon researches ways to make telemedicine safe and effective for pediatric patients with dermatological issues. He has conducted studies that confirm the safety and ease of teledermatology. He researches the benefits for patient care, including how it can improve wait times to receive advice and treatments.

Education and Training

Medical School

MD - Stony Brook School of Medicine, Stony Brook, NY


Pediatrics - The Children's Hospital of Philadelphia, Philadelphia, PA


Pediatrics - The Children's Hospital of Philadelphia, Philadelphia, PA
Dermatology - University of California-San Francisco, San Francisco, CA (Chief Resident)


Pediatric Dermatology - The Children's Hospital of Philadelphia, Philadelphia, PA

Board Certification

Pediatric Dermatology

Titles and Academic Titles

Attending Physician

Medical Director, Teledermatology

Assistant Professor of Pediatrics and Dermatology, Perelman School of Medicine at the University of Pennsylvania

Departments and Services

Research Interests

Improving access to care




Boulos S, Rubin AI, Yan AC, McMahon PJ, Perman MJ. Unilateral hypertrophy of the labia minora: A case series. Pediatr Dermatol. 2018 May;35(3):e198-e199.


O'Connor D, MD, Jew, O, MS, Castelo, L, MD,PhD, Perman, M, MD, Winston, F, MD, McMahon, P, MD. Diagnostic Accuracy of Pediatric Teledermatology using Parent-Submitted Photographs. JAMA Dermatol. 2017 Dec 1;153(12):1243-1248.

Fiks AG, Fleisher L, Berrigan L, Sykes E, Mayne SL, Gruver R, Halkyard K, Jew OS, FitzGerald P, Winston F, McMahon P. Usability, Acceptability, and Impact of a Pediatric Teledermatology Mobile Health Application. Telemed J E Health. 2018 Mar;24(3):236-245.

Janice Tiao, Dr. Rui Feng, Dr Emily M Berger, Dr John F Brandsema, Dr Carrie C Coughlin, Neelam Khan, et al. Evaluation of the reliability of the Cutaneous Dermatomyositis Disease Area and Severity Index and the Cutaneous Assessment Tool-Binary Method in juvenile dermatomyositis among paediatric dermatologists, rheumatologists and neurologists. Br J Dermatol. 2017 Oct;177(4):1086-1092.

Castelo-Soccio L, McMahon P. Pediatric Dermatology. J Clin Aesthet Dermatol. 2017 Mar; 10(3): S8–S15.


Boos M, McMahon P, Castelo-Soccio L.: A Progressive Blistering Eruption in a 5-Month-Old Male Infant. Am J Dermatopathol 38(8): 634-5, Aug 2016.

Robert Smith MS, Markus Boos, MD/PhD, Patrick McMahon, MD: Probable Griseofulvin-Induced Drug Reaction with Eosinophilia and Systemic Symptoms in a Child. Pediatric Dermatology Sept 2016.

Yang TB, McMahon P, De Léon DD, Treat JR: Use of Propranolol for Treating Hemangiomas in Infants with Previously Diagnosed Hypoglycemic Conditions. Pediatric Dermatology 33(6): 381-384, Nov 2016.


McMahon P, Goddard D, Frieden IJ: Pediatric dermatology inpatient consultations: A retrospective study of 427 cases. J Am Acad Dermatol Jan 2013.

Cobos G, Cornejo C, McMahon P.: A Case of Phrynoderma in a Patient with Crohn's Pediatric Dermatology Nov 2013.


Van Loon K, Gill RM, McMahon P, Chigurupati R, Siddiqi I, Fox L, Damon L, McCalmont TH, Jordan R, Wolf J.: 20q- clonality in a case of oral sweet syndrome and myelodysplasia. Am J Clin Pathol Feb 2012.

Boos MD, McMahon P, Castelo-Soccio L. Acute onset of a hemorrhagic rash in an otherwise well-appearing infant. J Pediatr. 2012 Jul 18. Cited in PubMed; PMID 22817909. No abstract available.

McMahon PJ, Treat JR.: An 11-month-old boy with widespread itchy, crusted, and weeping plaques. Pediatr Ann. Aug 2012.

Pulido J, McMahon P, Treat JR, Gunselman J, Tasian GE, Tasian SK: Labial Ecthyma Gangrenosum in an Immunocompromised Infant With Leukemia: Heightening Awareness for the Urologist. Urology Oct 2012.

Goff KL, Gormley RH, McMahon PJ, Rubin AI, Castelo-Soccio L.: Picture of the month-quiz case. Arch Pediatr Adolesc Med. Dec 2012.



Olivia Jew, MS and Patrick McMahon, MD: Direct-to-patient teledermatology mobile health app aimed at shortening wait times for new patients (live poster). World Congress of Pediatric Dermatology, Chicago, IL July 2017.



William James, MD; Patrick McMahon, MD; Dirk Elston, MD: Andrew's Atlas of Dermatology. Elsevier March 2017.



Marcia Hogeling, MD: Inpatient Pediatric Dermatology Textbook. Chapter on viral diseases in the hospitalized child. Springer, 1 May 2016.


Fleisher & Ludwig: Pediatric Emergency Medicine Textbook. Chapter on Dermatitis and Erythroderma. Lippincott, 7 November 2015

Awards and Honors

2018, Faculty Honor Roll, General Pediatrics, Children's Hospital of Philadelphia. Awarded by pediatric residents to faculty who demonstrate dedication to medical education

2017, Healthcare Innovator Award, Philadelphia Business Journal

2016, Chosen as an Influential Physician Mentor by The Cornfield Society Pediatric Interest Group at The UPENN Perelman School of Medicine

2015, CHOP SPRINT Entrepreneurship and Innovation Award Recipient for development of dermatology app, awarded by CHOP Office of Entrepreneurship and Innovation.

2015, Medical Student Teaching Award in Dermatology, awarded to the faculty member who demonstrates exceptional dedication to instructing, teaching and mentoring medical students

Editorial and Academic Positions

Editorial positions

2015-Present, Editor/Primary Author, "Andrew's Atlas of Dermatology"

Academic and Institutional Committees

2016-2018, Chair of the Society of Pediatric Dermatology Committee on Teledermatology
2014-Present, Society for Pediatric Dermatology Education Committee

Leadership and Memberships

2008-Present, Society for Pediatric Dermatology
2008-Present, American Academy of Dermatology
2005-Present, American Academy of Pediatrics