Introduction: Pyoderma gangrenosum (PG) is a rare inflammatory disorder with an incidence of 0.63 per 100,000 person years1 . It is a sterile inflammatory neutrophilic dermatosis2,5, associated with recurrent cutaneous ulcerations with mucopurulent or haemorrhagic exudate. The peak age of incidence is from 20 to 50 with a female preponderance2,3. Although the lower legs are common sites for PG, other sites including breast, hand, trunk and peristomal skin have been reported2 .
Case Presentation: A 36 year old waiter was referred to the dermatology outpatient clinic in 2011 with an 18 month history of non-healing ulcer of his right malleolus measuring 2cm in diameter sustained post trauma. Differential diagnoses included Buruli ulcer and Madura foot. MRI scans excluded osteomyelitis. Biopsies of several sites including the skin of the tibial malleolus and posterior aspect of the ankle revealed necrosis of the underlying dermis and deep tissue. Stains for fungi and Acid Fast Bacilli were negative. Based on clinical presentation and the histology report, a diagnosis of pyoderma gangrenosum (PG) was made.
Management: Patient was initially treated with Prednisolone and topical Trimovate cream. Within 6 months, the ulcer extended, exposing the tibialis posterior and tendo Achilles. The patient underwent debridement and VAC therapy secondary to bleeding from the edge of the site of PG. He was later commenced on Azathioprine. Six months later, patient underwent a failed skin grafting of the right ankle. The PG worsened into a circumferential deep ulceration of the leg, extending to just below the knee. He was admitted with cellulitis and commenced on Ciclosporin and Minocycline. Four years after first presentation, the PG has demonstrated erosion to major blood vessles. A referral was made to the vascular team to consider the need of a below knee amputation. Three weeks into the pending vascular review, patient sustained a significant haemorrhage whilst receiving wound care at the dermatology department and went into hypovolaemic shock. A departmental crash call was placed and he received fluid resuscitation before being transferred to the A&E department at a separate hospital site. The patient subsequently underwent an emergency below knee amputation and regained significant mobility and quality of life thereafter.
Discussion: This case has a significant impact on the clinical practice in the dermatology department leading to two major changes as follows:
1) the improvement of advanced life support skills amongst clinical staff
2) the initiation of earlier vascular referral in cases of pyoderma gangrenosum with vascular involvement.
Conclusion: The outlook for patients suffering from PG remains poor3 . Despite systemic and topical therapies2,5, the recurrence and mortality rates remain high3 . Therefore, management of modifiable factors including wound management and preventing systemic compromise is paramount3 . Changes incorporated in clinical practice as the result of this case will benefit future acute and long term management of all dermatology patients, not exclusive to those with PG