1 EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in this Post-Effective Amendment No. 1 to the Registration Statement of DUSA Pharmaceuticals, Inc. on Form S-8 of our report dated February 23, 2001, appearing in the Annual Report on Form 10-K of DUSA Pharmaceuticals, Inc. for the year ended December 31, 2000. /s/ DELOITTE & TOUCHE LLP Boston, Massachusetts September 5, 2001