Pyoderma gangrenosum: mis-diagnosed as necrotizing fasciitis and review of local experience in patients’ characteristics, associated disease and therapy

Authors

  • Christina S.M. Wong 1 Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Martin MH Chung Division of Rheumatology and Immunology, Department of Medicine , Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Johann Lok Division of Anatomical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China Author
  • Nigel Trendell Smith Division of Anatomical Pathology, Department of Pathology, Queen Mary Hospital, Hong Kong SAR, China Author
  • Mandy WM Chan Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Adrian KC Cheng Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Yuk-Ming Lau 1 Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Chi-Keung Yeung 1 Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author
  • Henry HL Chan Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China Author

DOI:

https://doi.org/10.33425/2768-4598.1005

Abstract

Pyoderma gangrenosum (PG) is a rare non-infectious, inflammatory neutrophilic dermatosis that can be idiopathic or associated with underlying autoimmune or neoplastic disorders. It is often diagnosed by exclusion with no gold standard for diagnosis and treatment. We described a 38-year old diabetic lady who presented with rapidly deteriorating ulceration over right foot with extensive suppuration, misdiagnosed as ‘necrotizing fasciitis’ with multiple surgical debridement and amputation was planned. A clinical diagnosis of PG was made after skin biopsy reviewed. She responded significantly after systemic pulsed methylprednisolone therapy and her leg was salvaged. In our local experience of 12 cases with PG follow-up in 5-year period, 83.3% were associated with underlying systemic disease and lower limbs (91%) were the most common site of involvement. Non-healing ulcer (100%) was most frequent presenting symptoms followed by pustule or blister formation. An average of 1.67 skin biopsies were performed for diagnosis. The mean duration of disease before remission was 13.2 ± 6.4 months. Importantly, one-third of cases had experienced relapse. Systemic corticosteroid was mostly given during acute phase, followed by cyclosporin, mycophenolate, azathioprine and anti-tumor necrosis factor (TNF). Conclusion: PG should be considered in patients with non-healing ulcers, especially over lower limbs after exclusion of other cause(s). Systemic corticosteroid during acute phase followed by immunosuppressants resulted in disease control. Continuous monitoring is required as relapse may occur.

Published

2025-07-30

Issue

Section

Articles