A 53 y.o. woman with a hx of colon cancer sp chemo and proctocolectomy with ileostomy comes to the ED with ulcers around her ostomy site.
what is wrong?
Our patient had biopsy proven pyoderma gangrenosum. This is a sterile inflammatory neutrophilic dermatosis with raised borders. It belongs to a group of diseases which include Behcet’s and Sweet’s syndrome. The lesions of pyoderma gangrenosum begin with sterile pustules that rapidly turn into painful ulcers. Pyoderma are found frequently around stoma sites.
Another pyoderma gangrenosum lesion showing the “cat’s paw” variant
The term was first introduced in 1930 when Brunsting described four cases associated with ulcerative colitis. Since that time, in addition to autoimmune diseases, they have been associated with inflammatory disorders( chronic infection or arthritis) hematologic disorders and malignancy, In about half of the cases no cause is found.
The cause is thought to be an overstimulation of neutrophil chemotaxis and immune dysregulation. Abnormal cytokine signaling by T cells and macrophages occurs. An individual with pyoderma may get lesions repeatedly because of a phenomenon known as pathergy. Although the exact reason is not known these individuals have an exaggerated response to minor skin injuries.
History is important in making the diagnosis, substances like bromide can cause similar lesions. Bromides are found in pesticides and disinfectants.
THE DIFFERENTIAL
Other entities can mimic pyoderma and bacterial infections, arterial ulcers, vasculitis, Martorell ulcers and mycobacterial infections must be ruled out by biopsy.
Martorell ulcers are thought to be due to narrowing of small blood vessels in the skin caused by longstanding hypertension. This is a form of arterial vascular disease affecting the skin so peripheral pulses are intact.
Martorell ulcers are peripheral vascular disease in the skin.
Bacterial diseases like anthrax must be ruled out.
The treatment of limited pyoderma lesions includes intralesional steroids or topical tacrolimus. Anti-TNF-alpha drugs such as etanercept and adalimumab are also useful. Our patient underwent intralesional injections of steroids and is improving. David F, Freitas R, Bras-Cruz R, et al. A case of recurrent idiopathic pyoderma gangrenosum. Cureus doi: 10.7759/cureus.25112.
Wollina U, Pyodrema gangrenosum—a review. Orphanet Journal of Rare Diseases 2007 2, (19)
Ashchyan H, Butler D, Nelson C, et al. the association of age with clinical presentation and comorbidities of pyoderma gangrenosum. JAMA Dermatol. 2018 Apr 1.154(4):409-413.
Honma M, Sugawara M, Ueno N,et al. Clinical characteristics of peristomal pyoderma gangrenosum. A single center retrospective observational study. The Journal of Dermatlogy. 2022. https://doi.org/10.1111/1346-8138.16504