Pyoderma Gangrenosum Involving all Four Extremities

Pyoderma gangrenosum (PG) is a rare inflammatory ulcerative condition that occurs in less than 10 cases per million people per year. Diagnosing this condition is difficult as there are no definitive serological or histopathological markers, and it is considered a clinical diagnosis of exclusion. The authors present a unique case of PG involving all 4 extremities—a distribution not previously reported. This case highlights the importance of a comprehensive and systematic workup of these patients; early recognition of PG, which can have unusual presentations; and a cautious approach to surgical debridement.

Pyoderma gangrenosum (PG) is an uncommon inflammatory ulcerative condition, occurring in fewer than 10 cases per million people per year.^1,2 Because of a lack of definitive serological or histopathological markers, diagnosing PG is difficult, and it is considered a clinical diagnosis of exclusion.³ Classically, PG presents as a violaceous or erythematous ulcerative skin lesion with a necrotic center that may produce discharge; other variants include pustular, bullous, and vegetative.⁴ Incorrect or delayed diagnosis may prolong patient suffering and cause unnecessary morbidity. The authors present a unique case of PG involving all 4 extremities — a distribution not previously reported.

A 62-year-old man with a history of ulcerative colitis (UC) initially presented to the Vascular Surgery clinic with a 2-week history of ischemia and painful ulcerations involving digits of both feet, indicating possible peripheral vascular disease. His vascular exam was normal, and investigations (including CT angiogram of the aorta and lower extremities, chest X-ray, and ECG) were unremarkable. He was subsequently discharged home on Plavix (Bristol-Myers Squibb, New York, NY) based on the presumed diagnosis of embolic disease.

Two weeks later, this patient developed similar necrotic lesions on his hands, and was admitted for pain control and further workup (Figure 1). The lesions demonstrated stocking-and-glove pattern but had cribriform areas of sparing. Subspecialty consultation workup for hypercoagulability and vasculitis were negative. He was treated with cefazolin by the Infectious Diseases service for an incidental asymptomatic finding of methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia without fever or leukocytosis. A transesophageal echocardiogram did not reveal any vegetation. Computerized tomography (CT) scans of his chest, abdomen, and pelvis did not identify any malignancies or abscesses. Concurrently during this admission, his UC flared up and the Gastroenterology service started him on oral prednisone, titrating from 25 mg/day to 60 mg/day. The Plastic Surgery service was consulted for wound assessment and tissue biopsy. 

Pathology assessment of hand and foot tissue specimens revealed non-specific necrotic tissue with no evidence of vasculitis or infection. INADINE PVP-I Non-Adherent Dressing (Systagenix, An Aceltiy Company, San Antonio, TX) wound therapy was used. After 4 weeks in the hospital, the progression of lesions plateaued. Pyoderma gangrenosum was implicated as the culprit etiology based on the overall clinical and pathological findings, the pre-existing UC, and the exhaustive exclusion of alternate serological, pathological, and radiological findings. 

At 1-month follow-up, the lesions on both the hands and feet had dramatically regressed, further revealing the cribriform pattern and further contradicting any embolic etiology (Figure 2). Again, there were no clinical signs or symptoms of infection, hypercoagulability, or vegetation. He remained on cefazolin and a tapering dose of prednisone. Ongoing outpatient wound management was advocated, and the patient will be followed by the Plastic Surgery service in the event any digital amputations become necessary. 

Pyoderma gangrenosum is a rare and painful ulcerative soft-tissue condition that commonly occurs on the trunk and lower extremities. Its pathophysiology is poorly understood with no pathognomonic serological or histological findings.^5,6 The etiology is presumed to be immune mediated in which the cumulative effects of activated polymorphic neutrophils secondary to hyperactive cytokine signaling causes tissue necrosis.^1,2,5

Pyoderma gangrenosum can occur at any age but most commonly between the ages of 30 years and 50 years.⁷ It is associated with autoimmune diseases, particularly inflammatory bowel disease and lymphoproliferative disorders which may trigger the hyperactive inflammatory response.^2,3,8 It begins as an inflammatory pustule or nodule, which then gradually enlarges and ulcerates with an overhanging erythematous, violaceous, or grey border. Hemorrhagic or purulent discharge is possible. If multiple lesions occur, either simultaneously or sequentially, they may coalesce into 1 large lesion over time.

The diagnosis of PG is critical in guiding its management. Antibiotics and surgical debridement/excision are often carried out initially to treat the presumed necrotic infection, which may exacerbate the lesion due to pathergy.^9,10 In fact, it may even occur in relatively benign procedures such as a venipuncture.¹¹

Pyoderma gangrenosum of the hands is extremely rare; therefore, it has only been documented in case reports. The present case of bilateral hand and feet PG is the first to report this unusual and unfortunate distribution. This case fits all the diagnostic criteria for PG² (Table 1). In addition to these predominantly clinical criteria, PG is a diagnosis of exclusion necessitating a careful and thorough workup.¹¹ For example, cutaneous Wegener’s granulomatosis can present very similarly to PG, but it is distinguished by the presence of vasculitis on histology and positive c-ANCA or PR3-ANCA on bloodwork.^3,12  

Currently, there is no gold standard management algorithm for PG. The treatment strategy is empirical to address goals of controlling pain, inflammation, and superimposed infection of the wounds. Either local or systemic anti-inflammatory measures are chosen based on severity. Local management includes topical or intralesional injection of corticosteroids and calcineurin inhibitors and dressings to keep the wound moist.^3,11 A systemic steroid is reserved for extensive cases. Other immunomodulators used include infliximab, mycophenolate mofetil, azathioprine, methotrexate, and intravenous immunoglobulin.^7,11,13 Antibiotics, such as minocycline and dapsone, have a role in the management as adjuncts.^1,7,11 Hyperbaric oxygen therapy has also been mentioned in managing PG, because the oxygen-rich environment promotes angiogenesis and wound healing.^10,14,15 Surgical management has no defined role, except in select cases involving extensive necrotic or infected tissue or exposure of vital organs.³ To prevent worsening of the condition, avoid any unnecessary surgical debridement. Wound reconstruction can only be performed when PG is quiescent. 

The authors present a unique case of PG with widespread distribution involving all 4 extremities. Extensive workup did not reveal any infectious, embolic, or vasculitic etiologies. Fortunately, the patient was incidentally started on high-dose prednisone to treat his UC flare, and his PG responded well to the steroid. Herein, the authors recommend the importance of a comprehensive and systematic workup of these patients, early recognition of PG, and a cautious approach to surgical debridement. 

From the Division of Plastic & Reconstructive Surgery, McMaster University, Hamilton, Ontario, Canada

Address correspondence to:
Jiayi Hu, MD
Division of Plastic & Reconstructive Surgery
McMaster University
1280 Main Street West
Hamilton, Ontario, Canada
ON L8S 4L8
Jiayi.hu@medportal.ca

Disclosure: The authors disclose no financial or other conflicts of interest.