Pyoderma gangrenosum following gynaecological surgery.

A perimenopausal woman with abnormal uterine bleeding underwent a total laparoscopic hysterectomy and bilateral salpingo-oophorectomy. Her medical history was significant for morbid obesity, hypertension, hypothyroidism, asthma and hyperlipidaemia. She denied a history of inflammatory bowel disease or rheumatological disorders. Five 5 mm laparoscopic ports were used in the following positions: supraumbilical, suprapubic, lateral left of the umbilicus, and one in each bilateral lower quadrant. The surgery was completed in the routine manner, and she was discharged home in a stable condition on postoperative day 1. Pathology revealed adenomyosis with unremarkable fallopian tubes and ovaries. On postoperative day 5, she reported a fever of 39.1°C at home and a small amount of drainage from one incision site with minimal redness extending circumferentially. She was advised to come to the emergency department and presented there the following day with worsening fever, redness and pain at the incision sites. Her white blood cell count was elevated to 24×10 9 /L on admission. Blood cultures, urine culture and bacterial swabs from all five port sites were collected. Physical examination was remarkable for tenderness, induration and erythema extending 2–3 cm around the right lower quadrant incision site. There was bruising (purplish discolouration) and blistering overlying the incision site without purulence or fluctuance. The suprapubic site showed erythema extending 5 cm circumferentially while the other three port sites showed mild erythema.

On postoperative day 29, the patient defervesced, and her wound showed significant improvement ( figure 7 ). On postoperative day 31, she was discharged to inpatient rehabilitation. Treatment with prednisone was slowly tapered. By postoperative day 51, she had continued oral prednisone at 40 mg/day and there was significant improvement in her clinical picture ( figure 8 ). She was seen in the dermatology clinic on postoperative day 58 and her prednisone treatment continued to be tapered. The patient was clinically well with no signs of recurrence at that time. Her wound was completely closed by secondary intention at 12 months post hysterectomy. She intends to undergo panniculectomy in the future to create a more symmetrical abdominal appearance. Physical exam on postoperative day 29 after initiation of steroids at 60 mg/day. Physical exam on postoperative day 51 with steroid treatment tapered to 40 mg/day.

Per dermatologist recommendations, the patient began daily wet dressings rather than wet-to-dry dressing changes. On postoperative day 28, once all cultures were confirmed negative, antibiotics were discontinued, and she began treatment with prednisone at a dose of 60 mg/day. She tolerated the treatment well.

Pyoderma gangrenosum (PG) is a rare cutaneous disorder that is characterised by painful, rapidly progressing skin ulcers. The exact pathogenesis of PG is unclear but is believed to involve an autoimmune response triggered by trauma, infection or an underlying systemic disease. In fact, nearly half of the patients diagnosed with PG have an underlying systemic disease such as inflammatory bowel disease or a rheumatological disorder. 1 Studies have suggested that dysregulated immune responses, specifically an enhanced IL-1 pathway, may play a role in the pathogenesis of PG. 1 The prevalence of PG worldwide is estimated to be around 3–10 cases per million individuals. 2 It can occur in individuals of any age but commonly affects women aged 20–50 years. 3 Most notably, PG lesions demonstrate pathergy, a phenomenon where skin trauma triggers the development of new lesions at the site of injury. 4 The complex interplay of immunological factors and the manifestation of pathergy contribute to the diagnostic challenges of PG. Laboratory and histopathological findings of PG can vary widely, highlighting the need for clinicopathological correlation for accurate diagnosis. The classic clinical presentation of PG is a painful ulcer, commonly seen in the lower extremities. 1 These painful, rapidly progressing ulcers often have undermined, violaceous borders. PG is categorised into four clinical variants: ulcerative, pustular, bullous and vegetative. 1 Treatment options for PG include systemic steroids, which help reduce the formation of proinflammatory cytokines like IL-1α and IL-1β. Another therapeutic approach is the use of canakinumab, an anti-IL-1β antibody. 5 PG is a rare but serious postsurgical complication, and its diagnosis can be challenging as it often mimics conditions such as necrotising fasciitis. It is crucial to accurately identify the condition before initiating treatment with steroids, as misdiagnosis may worsen conditions such as necrotising fasciitis, making timely and precise diagnosis essential for appropriate management. We present a case of PG in a patient with a history of gynaecological surgery, highlighting the challenges in diagnosis and management of this rare condition.

PG is a rare and challenging condition that is rarely encountered in gynaecology. Prompt recognition, accurate diagnosis and early treatment are crucial to prevent poor outcomes. While PG commonly presents as a painful ulcer in the lower extremities, it can also manifest in surgical wounds, making it important to consider in the gynaecological setting. There are relatively few published cases of PG in the gynaecological setting. However, when it does occur, it can present a diagnostic and management conundrum due to its rarity and complexity. Risk factors for PG include underlying autoimmune diseases such as inflammatory bowel disease, diabetes, rheumatoid arthritis and haematological malignancies. 1 In our patient’s case, the development of PG following gynaecological surgery, despite the absence of other risk factors, highlights the need for vigilance in recognising this condition. Imaging can be misleading as PG can mimic necrotising fasciitis on MRI and other modalities. 6 Relying solely on imaging findings can render a delay in diagnosis; therefore, identifying the characteristic clinical and histological features of PG is very important. Early biopsy with interpretation by a dermatopathologist, if available, can be helpful. Treatment of PG is vastly different from management of necrotising fasciitis. Incorrect therapy can worsen the disease state and delay in care can be life threatening. Wound debridement in our patient’s case most likely worsened her condition due to pathergy, a phenomenon where trauma triggers an exaggerated inflammatory response. Approximately 20%–40% of PG cases occur following minor trauma or complications of surgery, most commonly breast and abdominal. 1 Accurate diagnosis and appropriate management of PG often requires a multidisciplinary approach involving gynaecologists, dermatologists, wound care specialists and rheumatologists. Histopathological examination of PG lesions typically reveals a dense infiltrate of neutrophils. The infiltration of neutrophils into the dermis is the histological hallmark of PG. 4 The exact mechanism of injury is not well understood, but it is believed that neutrophils play a significant role in tissue destruction. For example, neutrophils can lead to a sustained generation of reactive oxygen species, which may promote angiogenesis in ulcers. 1 The ulcerative variant of PG, the most common variant, is consistent with our patient’s presentation. In fact, of all the PG clinical variants, the ulcerative variant is more likely to be associated with a poorer prognosis. In addition, increasing age, the presence of systemic disease, high C-reactive protein (CRP) levels and clinical signs of wound infection are also associated with poorer prognosis. 4 The gynaecological postsurgical period can provide a susceptible environment for PG to develop, possibly due to the interplay of surgical trauma and an altered immune response. Specifically, postoperative PG (PPG) is a unique clinical variant that shares some aspects of PG while also exhibiting its own clinical features. 5 It is believed that operative trauma and pathergy contribute to the upregulation of inflammatory neutrophils, driving the clinical course of PPG. Hence, the term postoperative pyoderma gangrenosum is often used interchangeably with pathergic pyoderma gangrenosum. 7 PPG has less association with systemic disease than non-PPG, especially when considering underlying haematological dyscrasias. PPG frequently occurs at the site of the breast and the abdomen followed by the lower limbs and the chest. In contrast, non-operative PG frequently involves the lower extremities. 7 PPG has a predictable time of onset, presenting within a mean of 7 days after surgery. Symptoms begin with erythema around the surgical incision, which evolves slowly into larger areas of wound dehiscence and extreme pain that is out of proportion to the patient’s initial symptoms. 7 Unfortunately, PPG is often misdiagnosed due to its mimicry to wound infections and necrotising fasciitis, leading to the initiation of antibiotic therapy and wound debridement. Due to the phenomenon of pathergy, wound debridement worsens PPG, thus increasing morbidity from this detrimental condition. It is imperative that the differential diagnosis of postoperative wound dehiscence should include PPG. Because of the nature of pathergy, patients should be informed of the high risk of relapse of PPG should they choose to undergo a panniculectomy in the future. When approaching a suspected case of PG, clinical guidelines recommend a thorough evaluation to exclude underlying autoimmune diseases or other systemic conditions. A biopsy of the affected tissue is essential for histopathological examination. Prompt initiation of systemic immunosuppressive therapy, often with corticosteroids, is the mainstay of treatment. Other immunomodulatory agents, such as cyclosporine or biologics, may be considered in refractory cases. It is crucial to avoid surgical procedures or trauma in PG, as they can exacerbate the condition. Due to the diverse clinical and histopathological features of PG, an individualised approach to treatment and close monitoring are essential for optimal management of this challenging dermatological disorder. 4 In conclusion, although PG is not commonly encountered in gynaecology, its prompt recognition, diagnosis and treatment are necessary to prevent poor outcomes. The rarity of PG in the gynaecological setting emphasises the importance of awareness and an expert multidisciplinary approach for accurate diagnosis and appropriate management. Understanding the histopathological findings, the role of neutrophils in tissue destruction and the potential for pathergy in the gynaecological postsurgical period aids in the comprehensive management of this challenging condition. Pyoderma gangrenosum (PG) is a rare complication of surgery that is characterised by painful, rapidly progressing skin ulcers. Its diagnosis can be challenging as it often mimics conditions such as necrotising fasciitis. PG lesions demonstrate pathergy, a phenomenon where skin trauma triggers the development of new lesions at the site of injury. Therefore, surgical debridement is contraindicated in the management of PG. Systemic immunosuppressive therapy, often with corticosteroids, is the mainstay of treatment when PG is identified. Optimising medical management and consulting with dermatology are critical to avoid misdiagnosis or delay in care.

The imaging and clinical exam raised concern for necrotising fasciitis. Empiric antibiotic treatment was initiated with intravenous ceftriaxone and vancomycin. On postoperative day 7, the erythema surrounding the right lower quadrant port site expanded ( figure 2 ). Repeat CT imaging showed worsening subcutaneous inflammation in the right lower quadrant extending to the flank and proximal thigh ( figure 3 ). All cultures continued to show no growth. The patient underwent initial debridement of the necrotic tissue by general surgery. The final wound measured 27 cm from the midline laterally and 14 cm superior to inferior. The wound was packed with chlorpactin soaked gauze with plan to return to the operating room within 48 hours. Pathology revealed skin ulcer with acute suppurative inflammation. Physical exam demonstrating erythema, bruising and blistering of the right lower quadrant port site on postoperative day 7. CT imaging of the abdomen and pelvis on postoperative day 8 showing worsening skin thickening and subcutaneous inflammation in the right lower quadrant now extending to the flank and proximal thigh. On postoperative day 9, she underwent a second wound debridement where further necrotic tissue was removed and wet-to-dry dressing applied. Microscopy showed ulcerated skin and underlying subcutaneous tissue with marked acute inflammation and abscess formation. Vancomycin was discontinued, and she was transitioned to daptomycin. She remained afebrile with an increasingly elevated white blood cell count. On postoperative day 12, an abdominal wound-vac was placed at the bedside. Repeat imaging showed persistent skin thickening and subcutaneous inflammation. She continued to receive wet-to-dry dressing changes two times per day. The following day, she developed recurrent fever that persisted for the next 2 weeks, as well as continued leucocytosis, eventually peaking at 50×10 9 /L. Physical exam showed erythema extending around the periphery of the wound VAC with tenderness to palpation and new skin blistering at the wound edges. A third wound debridement was performed on postoperative day 16 with the final wound measuring 50 cm by 15 cm. Fever and leucocytosis persisted. Repeat CT imaging on postoperative day 21 showed no new abscesses or subcutaneous emphysema. The next day, she developed worsening erythema and desquamation of the wound edges ( figure 4 ). Physical exam at 3 weeks post hysterectomy showing worsening erythema and desquamation of the wound edges. When it became clear that debridement and antibiotics were not treating the pathology, dermatology was consulted. They postulated that a differential diagnosis should include necrotising soft tissue infection versus PG, a neutrophilic dermatosis stemming from repetitive pathergy (multiple traumatic episodes) to the skin such as incurred by surgery and surgical debridement. Two punch biopsies were obtained per dermatopathologist request. The pathology report revealed tissue neutrophilia ( figure 5 ). The dermis was replaced by a sheet of neutrophils with collagen bundles without bacterial organisms or necrosis ( figure 6 ). This histology suggested a diagnosis of PG. Histology of the punch biopsy showing dermal neutrophilia without necrosis. Histology of the punch biopsy showing almost entirely neutrophils with karyorrhexis without bacterial organisms or necrosis.

An emergent CT scan of the abdomen and pelvis was performed with intravenous contrast, which revealed diffuse skin thickening near the right lower quadrant port site and a small air-and-fluid collection in the subcutaneous tissue near the supraumbilical port site ( figure 1 ). CT imaging of the abdomen and pelvis on postoperative day 6 showing ventral abdominal wall diffuse skin thickening most pronounced near the right lower quadrant port site and a small air collection within the subcutaneous tissue near the supraumbilical port site.