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Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis

Courtney Schadt, MD
Section Editor
Jeffrey Callen, MD, FACP, FAAD
Deputy Editor
Abena O Ofori, MD


Pyoderma gangrenosum (PG) is an uncommon neutrophilic dermatosis that presents as an inflammatory and ulcerative disorder of the skin. In contrast to its name, PG is neither an infectious nor gangrenous condition. The most common presentation of PG is an inflammatory papule or pustule that progresses to a painful ulcer with a violaceous undermined border and a purulent base (picture 1A-E). PG may also present with bullous, vegetative, peristomal, and extracutaneous lesions.

More than half of patients with PG develop the disorder in association with an underlying systemic disease. Inflammatory bowel disease, hematologic disorders, and arthritis represent the most frequent comorbidities.

A diagnosis of PG rests upon the recognition of consistent clinical and histologic findings and the exclusion of other inflammatory or ulcerative cutaneous disorders. There are no pathognomonic clinical or histologic findings of PG.

The pathogenesis, clinical manifestations, and diagnosis of PG will be discussed here. The treatment and prognosis of PG and other neutrophilic dermatoses are reviewed separately. (See "Pyoderma gangrenosum: Treatment and prognosis" and "Neutrophilic dermatoses".)


PG is a rare disorder with an estimated incidence of 3 to 10 cases per million people per year [1]. Individuals of any age may be affected, including children [2-4]. PG most commonly develops in young and middle aged adults, with an average age of onset between 40 and 60 years [5-8]. Between the sexes, women are more frequently affected [7].

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Literature review current through: Nov 2017. | This topic last updated: Oct 26, 2017.
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  1. Ruocco E, Sangiuliano S, Gravina AG, et al. Pyoderma gangrenosum: an updated review. J Eur Acad Dermatol Venereol 2009; 23:1008.
  2. Allen CP, Hull J, Wilkison N, Burge SM. Pediatric pyoderma gangrenosum with splenic and pulmonary involvement. Pediatr Dermatol 2013; 30:497.
  3. Bhat RM, Shetty SS, Kamath GH. Pyoderma Gangrenosum in childhood. Int J Dermatol 2004; 43:205.
  4. Torrelo A, Colmenero I, Serrano C, et al. Pyoderma gangrenosum in an infant. Pediatr Dermatol 2006; 23:338.
  5. von den Driesch P. Pyoderma gangrenosum: a report of 44 cases with follow-up. Br J Dermatol 1997; 137:1000.
  6. Bennett ML, Jackson JM, Jorizzo JL, et al. Pyoderma gangrenosum. A comparison of typical and atypical forms with an emphasis on time to remission. Case review of 86 patients from 2 institutions. Medicine (Baltimore) 2000; 79:37.
  7. Binus AM, Qureshi AA, Li VW, Winterfield LS. Pyoderma gangrenosum: a retrospective review of patient characteristics, comorbidities and therapy in 103 patients. Br J Dermatol 2011; 165:1244.
  8. Saracino A, Kelly R, Liew D, Chong A. Pyoderma gangrenosum requiring inpatient management: a report of 26 cases with follow up. Australas J Dermatol 2011; 52:218.
  9. Ahronowitz I, Harp J, Shinkai K. Etiology and management of pyoderma gangrenosum: a comprehensive review. Am J Clin Dermatol 2012; 13:191.
  10. Adachi Y, Kindzelskii AL, Cookingham G, et al. Aberrant neutrophil trafficking and metabolic oscillations in severe pyoderma gangrenosum. J Invest Dermatol 1998; 111:259.
  11. Alberts JH, Sams HH, Miller JL, King LE Jr. Familial ulcerative pyoderma gangrenosum: a report of 2 kindred. Cutis 2002; 69:427.
  12. Khandpur S, Mehta S, Reddy BS. Pyoderma gangrenosum in two siblings: a familial predisposition. Pediatr Dermatol 2001; 18:308.
  13. al-Rimawi HS, Abuekteish FM, Daoud AS, Oboosi MM. Familial pyoderma gangrenosum presenting in infancy. Eur J Pediatr 1996; 155:759.
  14. Shands JW Jr, Flowers FP, Hill HM, Smith JO. Pyoderma gangrenosum in a kindred. Precipitation by surgery or mild physical trauma. J Am Acad Dermatol 1987; 16:931.
  15. Wise CA, Gillum JD, Seidman CE, et al. Mutations in CD2BP1 disrupt binding to PTP PEST and are responsible for PAPA syndrome, an autoinflammatory disorder. Hum Mol Genet 2002; 11:961.
  16. Farasat S, Aksentijevich I, Toro JR. Autoinflammatory diseases: clinical and genetic advances. Arch Dermatol 2008; 144:392.
  17. Guenova E, Teske A, Fehrenbacher B, et al. Interleukin 23 expression in pyoderma gangrenosum and targeted therapy with ustekinumab. Arch Dermatol 2011; 147:1203.
  18. Oka M, Berking C, Nesbit M, et al. Interleukin-8 overexpression is present in pyoderma gangrenosum ulcers and leads to ulcer formation in human skin xenografts. Lab Invest 2000; 80:595.
  19. Powell FC, Hackett BC, Wallach D. Pyoderma gangrenosum. In: Fitzpatrick's Dermatology in General Medicine, 8th ed, Goldsmith LA, Katz SI, Gilchrest BA, et al (Eds), McGraw-Hill Companies, Inc., New York 2012. Vol 1, p.371.
  20. Wong WW, Machado GR, Hill ME. Pyoderma gangrenosum: the great pretender and a challenging diagnosis. J Cutan Med Surg 2011; 15:322.
  21. Callen JP, Jackson JM. Pyoderma gangrenosum: an update. Rheum Dis Clin North Am 2007; 33:787.
  22. Nico MM, Hussein TP, Aoki V, Lourenço SV. Pyostomatitis vegetans and its relation to inflammatory bowel disease, pyoderma gangrenosum, pyodermatitis vegetans, and pemphigus. J Oral Pathol Med 2012; 41:584.
  23. Brown TS, Marshall GS, Callen JP. Cavitating pulmonary infiltrate in an adolescent with pyoderma gangrenosum: a rarely recognized extracutaneous manifestation of a neutrophilic dermatosis. J Am Acad Dermatol 2000; 43:108.
  24. Fukuhara K, Urano Y, Kimura S, et al. Pyoderma gangrenosum with rheumatoid arthritis and pulmonary aseptic abscess responding to treatment with dapsone. Br J Dermatol 1998; 139:556.
  25. Abdelrazeq AS, Lund JN, Leveson SH. Pouchitis-associated pyoderma gangrenosum following restorative proctocolectomy for ulcerative colitis. Eur J Gastroenterol Hepatol 2004; 16:1057.
  26. Nurre LD, Rabalais GP, Callen JP. Neutrophilic dermatosis-associated sterile chronic multifocal osteomyelitis in pediatric patients: case report and review. Pediatr Dermatol 1999; 16:214.
  27. East-Innis A, Desnoes R, Thame K, et al. Pyoderma gangrenosum associated with osteomyelitis in a paediatric patient: a case report. West Indian Med J 2005; 54:207.
  28. Goldshmid O, Dovorish Z, Zehavi T, et al. Coexistent pyoderma gangrenosum and tibialis anterior myositis as presenting manifestations of Crohn's disease: case report and review of the literature. Rheumatol Int 2011; 31:525.
  29. Wilson DM, John GR, Callen JP. Peripheral ulcerative keratitis--an extracutaneous neutrophilic disorder: report of a patient with rheumatoid arthritis, pustular vasculitis, pyoderma gangrenosum, and Sweet's syndrome with an excellent response to cyclosporine therapy. J Am Acad Dermatol 1999; 40:331.
  30. Brown BA, Parker CT, Bower KS. Effective steroid-sparing treatment for peripheral ulcerative keratitis and pyoderma gangrenosum. Cornea 2001; 20:117.
  31. Teasley LA, Foster CS, Baltatzis S. Sclerokeratitis and facial skin lesions: a case report of pyoderma gangrenosum and its response to dapsone therapy. Cornea 2007; 26:215.
  32. Vadillo M, Jucgla A, Podzamczer D, et al. Pyoderma gangrenosum with liver, spleen and bone involvement in a patient with chronic myelomonocytic leukaemia. Br J Dermatol 1999; 141:541.
  33. Chanson P, Timsit J, Kujas M, et al. Pituitary granuloma and pyoderma gangrenosum. J Endocrinol Invest 1990; 13:677.
  34. Koester G, Tarnower A, Levisohn D, Burgdorf W. Bullous pyoderma gangrenosum. J Am Acad Dermatol 1993; 29:875.
  35. Scherlinger M, Guillet S, Doutre MS, et al. Pyoderma gangrenosum with extensive pulmonary involvement. J Eur Acad Dermatol Venereol 2017; 31:e214.
  36. Tolkachjov SN, Fahy AS, Wetter DA, et al. Postoperative pyoderma gangrenosum (PG): the Mayo Clinic experience of 20 years from 1994 through 2014. J Am Acad Dermatol 2015; 73:615.
  37. Farhi D, Cosnes J, Zizi N, et al. Significance of erythema nodosum and pyoderma gangrenosum in inflammatory bowel diseases: a cohort study of 2402 patients. Medicine (Baltimore) 2008; 87:281.
  38. Powell FC, Schroeter AL, Su WP, Perry HO. Pyoderma gangrenosum: a review of 86 patients. Q J Med 1985; 55:173.
  39. Marzano AV, Trevisan V, Gattorno M, et al. Pyogenic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PAPASH): a new autoinflammatory syndrome associated with a novel mutation of the PSTPIP1 gene. JAMA Dermatol 2013; 149:762.
  40. Braun-Falco M, Kovnerystyy O, Lohse P, Ruzicka T. Pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH)--a new autoinflammatory syndrome distinct from PAPA syndrome. J Am Acad Dermatol 2012; 66:409.
  41. Marzano AV, Ishak RS, Colombo A, et al. Pyoderma gangrenosum, acne and suppurative hidradenitis syndrome following bowel bypass surgery. Dermatology 2012; 225:215.
  42. Marzano AV, Ceccherini I, Gattorno M, et al. Association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) shares genetic and cytokine profiles with other autoinflammatory diseases. Medicine (Baltimore) 2014; 93:e187.
  43. Koshelev MV, Garrison PA, Wright TS. Concurrent hidradenitis suppurativa, inflammatory acne, dissecting cellulitis of the scalp, and pyoderma gangrenosum in a 16-year-old boy. Pediatr Dermatol 2014; 31:e20.
  44. Al Ghazal P, Herberger K, Schaller J, et al. Associated factors and comorbidities in patients with pyoderma gangrenosum in Germany: a retrospective multicentric analysis in 259 patients. Orphanet J Rare Dis 2013; 8:136.
  45. Jeong HS, Layher H, Cao L, et al. Pyoderma gangrenosum (PG) associated with levamisole-adulterated cocaine: Clinical, serologic, and histopathologic findings in a cohort of patients. J Am Acad Dermatol 2016; 74:892.
  46. Su WP, Davis MD, Weenig RH, et al. Pyoderma gangrenosum: clinicopathologic correlation and proposed diagnostic criteria. Int J Dermatol 2004; 43:790.
  47. Weedon D. The vasculopathic reaction pattern. In: Weedon's Skin Pathology, 3rd ed, Elsevier Limited, 2010. p.195.
  48. Weenig RH, Davis MD, Dahl PR, Su WP. Skin ulcers misdiagnosed as pyoderma gangrenosum. N Engl J Med 2002; 347:1412.
  49. Touil LL, Gurusinghe DA, Sadri A, et al. Postsurgical Pyoderma Gangrenosum Versus Necrotizing Fasciitis: Can We Spot the Difference? Ann Plast Surg 2017; 78:582.
  50. Hradil E, Jeppsson C, Hamnerius N, Svensson Å. The diagnosis you wish you had never operated on: Pyoderma gangrenosum misdiagnosed as necrotizing fasciitis-a case report. Acta Orthop 2017; 88:231.
  51. Berger N, Ebenhoch M, Salzmann M. Postoperative Pyoderma Gangrenosum in Children: The Case Report of a 13-Year-Old Boy With Pyoderma Gangrenosum After Hip Reconstruction Surgery and a Review of the Literature. J Pediatr Orthop 2017; 37:e379.