Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

Exagen Inc.

Vista, California

We hereby consent to the incorporation by reference in the Prospectus constituting a part of this Registration Statement of our report dated March 20, 2023, relating to the financial statements of Exagen Inc. appearing in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022.

We also consent to the reference to us under the caption “Experts” in the Prospectus.

/s/ BDO USA, P.C.

San Diego, California

November 17, 2023