Abstract Number: 7

Recalcitrant ulcerative pyoderma gangrenosum of the leg histologically mimicking squamous cell carcinoma and pseudoepitheliomatous hyperplasia responsive to tildrakizumab

Liang Joo Leow, Natalie Teh, Nicolas Zubrzycki

Meeting: 2022 Dermcoll

Session Information

Date: -

Session Title: Biologics

Session Time: -

Background: The treatment of pyoderma gangrenosum is challenging, and there is no national or international treatment guideline to assist clinicians nor is there any consensus on a specific therapeutic approach. The monoclonal antibody tildrakizumab specifically neutralises interleukin-23, a cytokine implicated in the pathogenesis of pyoderma gangrenosum.

Methods: We present a case of response to tildrakizumab by the most common clinical variant and disease site of pyoderma gangrenosum. Interestingly, microscopic features mimicked squamous cell carcinoma and pseudoepitheliomatous hyperplasia, which are rarer but well-reported histologic variants. Our patient is an elderly woman who presented with widespread, treatment-refractory ulceration from pyoderma gangrenosum of the left leg, and previously faced the threat of amputation. In our approach, subcutaneous tildrakizumab 100 mg was combined with daily conventional ulcer care.

Results: Our treatment regimen resulted in re-epithelialisation, recovery of sensory perception, and a distinct decrease in the size and depth of the ulcer; with no safety concern.

Conclusion: Our observations encourage the inclusion of tildrakizumab as an effective systemic treatment option for patients with pyoderma gangrenosum.