Abstract
Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that may occur after surgery and mimic wound infection. We report the case of a 30-year-old woman who developed painful progressive ulceration 7 days after caesarean section. Initial treatment with broad-spectrum antibiotics for presumed surgical site infection was ineffective. Clinical examination showed a large hypogastric ulcer with an erythematous base and undermined inflammatory borders. Histopathological examination of a biopsy taken from the ulcer edge demonstrated a dense dermal neutrophilic infiltrate, supporting the diagnosis of PG. Oral prednisolone at 1 mg/kg/day was started, with progressive improvement and complete re-epithelialization after 4 months. This case highlights the importance of considering PG in postoperative wounds that worsen despite adequate antimicrobial treatment, in order to avoid unnecessary surgical procedures and initiate timely immunosuppressive therapy.
Introduction
Pyoderma gangrenosum (PG) is an uncommon neutrophilic dermatosis characterized by rapidly progressive and painful ulceration. Postsurgical PG is a recognized but rare entity and may be misdiagnosed as surgical site infection because both conditions may present with erythema, pain, fever, purulent discharge and elevated inflammatory markers [1, 2]. This distinction is important because surgical manipulation may worsen PG through pathergy, whereas immunosuppressive treatment is the cornerstone of management [3]. PG in pregnancy and the postpartum period is uncommon, and post-caesarean cases remain rare in the literature [4–8]. We report a case of postoperative PG following caesarean section initially treated as wound infection.
Case report
A 30-year-old woman with no significant past medical history underwent caesarean section at 38 weeks of gestation for acute fetal distress. The immediate postoperative course was uneventful.
On postoperative day 7, she developed painful bluish discoloration around the surgical scar associated with purulent discharge. Over the following days, circumferential erythema progressively extended around the incision and was associated with fever of 39°C. Surgical site infection was suspected. She received amoxicillin/clavulanic acid followed by flucloxacillin, together with nonsteroidal anti-inflammatory drugs and daily local wound care, without improvement after 7 days.
Because of progressive worsening, she was admitted to the plastic surgery department. Examination showed a painful central ulceration involving the whole hypogastric region, measuring 25 × 10 cm. Broad-spectrum dual antibiotic therapy with ciprofloxacin and amoxicillin/clavulanic acid was initiated. Laboratory tests showed marked inflammatory syndrome with leukocytosis of 20 000/mm3, predominantly neutrophils. Despite antibiotic escalation, the lesion continued to progress.
Dermatology consultation was requested. Clinical examination revealed a large ulcer with an erythematous base and undermined inflammatory borders (Fig. 1). A biopsy from the ulcer edge showed a dense dermal neutrophilic inflammatory infiltrate, consistent with neutrophilic dermatosis and compatible with PG (Fig. 2A–C).
Large hypogastric pyoderma gangrenosum ulcer with an erythematous base and undermined inflammatory borders.
Histopathological examination of a biopsy specimen obtained from the ulcer edge. (A) Low-power view showing epidermal changes associated with a dense inflammatory infiltrate involving the dermis. (B) High-power view highlighting a dense neutrophilic inflammatory infiltrate. (C) Intermediate-power view showing prominent dermal neutrophilic infiltration beneath the epidermis.
Based on the rapid progression, failure to respond to appropriate antibiotic therapy, characteristic morphology, and histopathological findings, postoperative PG was diagnosed. The patient was transferred to the dermatology department and treated with oral prednisolone 1 mg/kg/day (60 mg/day), associated with local wound care and twice-weekly LED sessions. Progressive improvement was observed. Complete re-epithelialization was achieved after 4 months (Fig. 3). Residual marginal hypertrophy was managed with topical corticosteroids.
Complete re-epithelialization after 4 months of systemic corticosteroid therapy.
Discussion
Postsurgical PG is a diagnostic challenge because it closely mimics wound infection in the early postoperative period [1–3]. In our patient, fever, neutrophilic leukocytosis, erythema, and purulent discharge initially supported an infectious diagnosis. However, the key clue was progressive deterioration despite adequate broad-spectrum antibiotic treatment. Similar diagnostic delay has been reported in post-caesarean PG, where lesions usually appear within the first postoperative week and rapidly extend centrifugally if the diagnosis is missed [3–8].
The pathergy phenomenon is central in postoperative PG. Even minor trauma may trigger or worsen lesions, which explains why repeated debridement can aggravate tissue destruction [3]. Recognition of this possibility is especially relevant for surgeons managing postoperative wounds that appear infected but behave atypically.
The Delphi consensus criteria for ulcerative PG include a major criterion of biopsy showing neutrophilic infiltrate, together with minor clinical criteria such as rapid progression, undermined borders, and exclusion of infection [9]. In our patient, histology and clinical evolution were strongly supportive of the diagnosis.
Systemic corticosteroids remain first-line treatment for moderate to severe PG, while ciclosporin is an alternative in selected patients [1, 2]. Biologic agents, especially anti-TNF therapies such as infliximab, may be useful in refractory disease [10]. In the present case, prompt corticosteroid therapy led to progressive healing and complete re-epithelialization. This favorable response further supported the diagnosis.
This case emphasizes that PG should be considered in any postoperative wound after caesarean section that worsens despite appropriate antimicrobial therapy. Early dermatological assessment may prevent unnecessary surgical procedures and accelerate appropriate treatment.
Conflicts of interest
The authors declare no conflict of interest.
Funding
None declared.
Patient consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images.
