Sam Tzen-yue Hwang, M.D., Ph.D. for UC Davis Health

Sam Tzen-yue Hwang, M.D., Ph.D.

Chair, Department of Dermatology

Professor, Department of Dermatology

To see if Sam Tzen-yue Hwang is accepting new patients, or for assistance finding a UC Davis doctor, please call 800-2-UCDAVIS (800-282-3284).






Locations and Contact


3301 C St.
Sacramento, CA 95816

Get Directions

Additional Numbers

Physician Referrals

800-4-UCDAVIS (800-482-3284)

Clinical Interests

Dr. Hwang practices general adult dermatology with a keen emphasis on inflammatory diseases of the skin such as psoriasis and atopic dermatitis. He conducts a rheumatology-dermatology clinic for patients with psoriasis and psoriatic arthritis. He welcomes patients with skin cancers as well to his practice.

Research/Academic Interests

Dr. Hwang is an acknowledged expert in the field of psoriasis research for which he received the American Skin Association's 2020 Research Achievement Award. He has over 100 publications in scientific and medical journals such as the Journal of Clinical Investigation, the Proceedings of the National Academy of Science, and the Journal of Investigative Dermatology that describe his research on the key mediators of inflammation in the skin disease known as psoriasis.



Center/Program Affiliation

UC Davis Comprehensive Cancer Center

Undergraduate School

A.B., Harvard University, Cambridge MA

Medical School

M.D., Harvard Medical School, Boston MA

Other School

Ph.D., University of Basel, Basel, Switzerland


Internal Medicine, Brigham and Women's Hospital, Boston MA


Dematology, UC San Francisco Medical Center, San Francisco CA


Howard Hughes Physician Fellow, Anatomy/Program in Immunology, UC San Francisco School of Medicine, San Francisco CA

Taiwanese Society for Investigative Dermatology Keynote Speaker, 2021

Taiwanese Dermatological Association Keynote Speaker, 2021

Japanese Dermatological Association Tokyo Section Plenary Speaker, 2021

American Skin Association Research Achievement Award in Psoriasis, 2020

Keynote Speaker, Taiwanese Society for Investigative Dermatology Annual Meeting, Kaohsiung, 2019

Others can be found here:

Shi Z, Garcia-Melchor E, Wu X, Getschman AE, Nguyen M, Rowland DJ, Wilson M, Sunzini F, Akbar M, Huynh M, Law T, Raychaudhuri SK, Raychaudhuri SP, Volkman BF, Millar NL, Hwang ST. Targeting the CCR6/CCL20 Axis in Entheseal and Cutaneous Inflammation. Arthritis Rheumatol. 2021 Dec;73(12):2271-2281. doi:10.1002/art.41882. Epub 2021 Nov 1. PMID:34081845.

Shi Z, Wu X, Santos Rocha C, Rolston M, Garcia-Melchor E, Huynh M, Nguyen M, Law T, Haas KN, Yamada D, Millar NL, Wan YY, Dandekar S, Hwang ST. Short-Term Western Diet Intake Promotes IL-23‒Mediated Skin and Joint Inflammation Accompanied by Changes to the Gut Microbiota in Mice. J Invest Dermatol. 2021 Jul;141(7):1780-1791. doi:10.1016/j.jid.2020.11.032. Epub 2021 Jan 22. PMID:33485880.

Shi Z, Wu X, Yu S, Huynh M, Jena PK, Nguyen M, Wan YY, Hwang ST. Short-Term Exposure to a Western Diet Induces Psoriasiform Dermatitis by Promoting Accumulation of IL-17A-Producing γδ T Cells. J Invest Dermatol. 2020 Sep;140(9):1815-1823. doi:10.1016/j.jid.2020.01.020. Epub 2020 Feb 10. PMID:32057839.

Getschman AE, Imai Y, Larsen O, Peterson FC, Wu X, Rosenkilde MM, Hwang ST, Volkman BF. Protein engineering of the chemokine CCL20 prevents psoriasiform dermatitis in an IL-23-dependent murine model. Proc Natl Acad Sci USA. 2017 Nov;114(47):12460-12465. doi:10.1073/pnas.1704958114.

Imai Y, Ayithan N, Wu X, Yuan Y, Wang L, Hwang ST. Cutting Edge: PD-1 Regulates Imiquimod-Induced Psoriasiform Dermatitis through Inhibition of IL-17A Expression by Innate γδ-Low T Cells. J. Immunol. 2015 Jul 15;195(2):421-5. doi:10.4049/jimmunol.1500448. Epub 2015 Jun 5. PMID:26048148.

Wu X, Schulte BC, Zhou YW, Haribhai D, Mackinnon AC, Plaza JA, Williams CB, Hwang ST. Depletion of M2-like tumor-associated macrophages delays cutaneous T cell lymphoma development in vivo. J Invest Dermatol. 2014 Nov;134(11):2814-2822. doi:10.1038/jid.2014.206. Epub 2014 Apr 29. PMID:24780929.

Mabuchi T, Singh TP, Takekoshi T, Jia GF, Wu X, Kao MC, Weiss I, Farber JM, Hwang ST. CCR6 Is Required for Epidermal Trafficking of γδ-T Cells in an IL-23-Induced Model of Psoriasiform Dermatitis. J Invest Dermatol. 2013 Jan;133(1):164-71. doi:10.1038/jid.2012.260. Epub 2012 Aug 16. PMID:22895364.

Wu X, Sells RE, Hwang ST. Upregulation of inflammatory cytokines and oncogenic signal pathways preceding tumor formation in a murine model of T-cell lymphoma in skin. J Invest Dermatol. 2011 Aug;131(8):1727-34. doi:10.1038/jid.2011.89. Epub 2011 Apr 14. PMID:21490619.

Mabuchi T, Takekoshi T, Hwang ST. Epidermal CCR6+ γδ T Cells Are Major Producers of IL-22 and IL-17 in a Murine Model of Psoriasiform Dermatitis. J Immunol. 2011 Nov 15;187(10):5026-31. doi:10.4049/jimmunol.1101817. Epub 2011 Oct 7. PMID:21984702.