Scalding as an unusual cause of pyoderma gangrenosum
Article Outline
1. Introduction
Pyoderma gangrenosum (P.G.) was first described in 1930 by Brunsting et al. [1], and is defined as an idiopathic neutrophilic dermatosis and was once considered pathognomonic of idiopathic ulcerative colitis. It has since been described in association with a wide variety of medical disorders, including Crohn's disease, diverticulitis, haematological and rheumatological conditions, hepatopathies, visceral carcinomata, and human immunodeficiency virus (HIV). A number of cases of P.G. occur secondary to an episode of trauma but in approximately 20–30% of cases no obvious cause can be identified [2]. This case report details the first published case of pyoderma gangrenosum secondary to scalding.
2. Case report
A 45 year old civil servant was admitted following referral from a peripheral unit for further management of a 1% total body surface area (T.B.S.A) suppurating wound to the left posterior shoulder. The wound had developed rapidly in the week following a scald injury sustained when boiling water from boiler passed down the U-bend of a sink while he was disassembling the connection. The patient was adamant that there had not been any pre-existing wounds or ulcers and that he had not recently sustained any bites or trauma to the area. Immediately after the injury the patient bathed the area in cold water for 15
min before applying an over-the-counter antiseptic cream. Over the next few days the wound became progressively more swollen and painful and he became increasingly more systemically unwell losing his appetite and suffering with hot flushes, which necessitated his presentation for medical attention. Further history from the patient illustrated a fit and healthy man with no previous medical complaints or wounds. He consumed forty units of alcohol a week, did not smoke or take any medication. He did not have any known allergies.
General examination of the patient found that he was pyrexial (39.4c) and to the posterior aspect of the left shoulder was a reddish-purple indurated area with pus exuding from pores within the skin surface (Fig. 1). Pus could be expressed from cutaneous pores by gentle massage of the area. Clinically there were no obvious deep collections to drain and this impression was confirmed by ultrasound examination. Routine plain chest and abdominal radiography were all normal. Betadine was applied and the wound dressed regularly with simple gelonet dressings. Intravenous flucloxacillin antibiotics were started on the basis of microbiological examination of pus samples, which contained a heavy growth of Staphylococcus aureus.
Fig. 1.
Pyoderma gangrenosum secondary to a scald wound to the posterior left shoulder. (i) Initial presentation of the lesion. Reddish-purple lesion with multiple sinuses exuding pus. There were no deep collections clinically or on ultrasound examination. (ii) Day 7 — the patient had been commenced upon oral Prednisolone and topical Dermovate NN® twice daily. (iii) a: Day 10 — the wound continues to improve; b: day 10 — closer image of the pyoderma gangrenosum ulcer. (iv) Day 30 — topical therapy had been changed to Tacrolimus at day 14 and the wound continued to improve dramatically; a: day 30 — topical therapy had been changed to Tacrolimus at Day 14 and the wound continued to improve dramatically. (v) a: Day 60 — the ulcer has healed but a violaceous area still persists; b: day 60 — closer image of the area showing that the ulcerated area has healed.
Given the unusual nature of the wound we considered a simple diagnosis of scalding unlikely. Careful considerations of other differential diagnoses such as folliculitis, vasculitis or even scalding coinciding with a secondary process were also explored in conjunction with our local dermatologists. Our working diagnosis was pyoderma gangrenosum and this was consistent with the subsequent results of punch biopsies taken from the ulcer edge at the junction between normal and inflamed skin.
The haematological and biochemical parameters confirmed that the patient was septic (white cell count 20.2×10−9/l, neutrophillia 15.5×10−9/l, C-reactive protein 368mg/l) and a previously undiagnosed diabetic with a random glucose of 31.4mmol/l. The admission blood results also demonstrated a mixed cholestatic picture which was thought by our hepatology and endocrinology team to be the result of hepatic fat infiltration secondary to diabetes and alcoholic intake. The only significant finding of an abdominal ultrasound was the presence of two hepatic lesions in keeping with haemangiomas. Further investigations were performed to rule out any other conditions, which may mimic or are associated with pyoderma gangrenosum [3]. The only significant result was from a macroscopically normal colonoscopy which yielded bowel biopsy specimens that were indicative of an acute colitis but with certain typical features such as neutrophilic infiltration of superficial crypts or epithelial injury absent.
The dermatologists commenced treatment with oral Prednisolone EC 40mg daily, gastric protection with Lanzoprazole and topical Dermovate NN® twice daily and on Day 14 of admission the topical therapy was changed to Tacrolimus 0.1%. The patient's condition improved rapidly (Fig. 1) and he was discharged from hospital on Day 30 with oral steroids on a reducing dose in combination with topical Tacrolimus that was stopped after 8 weeks. He is now undergoing long-term follow-up with our dermatology and gastroenterology teams.
3. Discussion
This case report describes the previously unreported situation of pyoderma gangrenosum (P.G.) developing secondary to a scald. As we learnt, there are no specific serological or histological markers for P.G. and it often said to be a “diagnosis made by exclusion”. Important differential diagnoses to rule out are vascular occlusive or venous diseases, vasculitis, cutaneous malignancies, primary infection, drug induced or inflammatory disorders which may often produce ulcers that mimic P.G. [3]. Our diagnosis of P.G. was made with a number of supporting elements that included a rapid onset in addition to the clinical appearances. Clinical examination of classic P.G. should demonstrate a centrifugally expanding ulcer with a necrotic centre that is filled with pus, blood and granulation tissue. Our lesion presented with superficial necrosis (Fig. 1) but other lesions may be deeper, not only involving the skin but also subcutaneous tissue, fascia, and rarely muscle. The boggy, slightly raised border was characteristically deep red, but can be purple or dusky blue with an undermined, ragged, overhanging edge. The clinical diagnosis was further confirmed by our ability to express a purulent discharge from sinus tracts at the violaceous border and base of the ulcer. It is often said that microbiological samples obtained from ulcers are sterile when sent for examination but if the lesion is long standing then secondary bacterial infection is possible.
Most P.G. ulcers are situated in the pretibial region but they can be sited anywhere. Tay et al. described P.G. of the fingers, which resulted in a patient undergoing multiple debridements with a suspected diagnosis of necrotising soft tissue [4]. In about forty percent of cases, P.G. is secondary to minor trauma and this is termed “pathergy”. It is well recognised that surgical wounds are a significant cause of pathergic pyoderma gangrenosum. Gudi et. al. made the diagnosis of P.G. 28 months after the dehiscence of a mammaplasty wound that failed to heal following surgical debridements [5]. Armstrong et al. diagnosed P.G. in a total hip replacement wound that dehisced on Day 2 post-operatively, interestingly they describe the patient having suffered with a dog bite wound that ulcerated and was extensively debrided before the diagnosis of P.G. was made.
The exact aetiology of P.G. remains unknown, but its relationship with other immunological disorders and its response to immunomodulating drugs suggests it may represent an over-reactive inflammatory response to traumatic, inflammatory, or neoplastic processes in susceptible persons. As P.G. is related to a number of medical disorders (Table 1) it is essential that newly diagnosed patients are screened appropriately and undergo long-term follow-up since it is not unusual for P.G. to predate presentation of associated conditions by a decade.
Table 1. Medical conditions associated with pyoderma gangrenosum (taken from Callen JP, Adv Dermatol 1989 [7])
| Diseases associated with pyoderma gangrenosum |
|---|
| Common associations |
| Inflammatory bowel disease |
| Chronic ulcerative colitis |
| Regional enteritis, granulomatous colitis (Crohn's disease) |
| Arthritis |
| Seronegative with inflammatory bowel disease |
| Seronegative without inflammatory bowel disease |
| Rheumatoid arthritis |
| Spondylitis |
| Osteoarthritis |
| Hematologic diseases |
| Myelocytic leukemias |
| Hairy cell leukemia |
| Myelofibrosis, agnogenic myeloid metaplasia |
| Monoclonal gammopathy (IgA) |
| Rarely reported associations |
| Chronic active hepatitis |
| Myeloma |
| Polycythemia rubra vera |
| Paroxysmal nocturnal hemoglobinuria |
| Takayasu's arteritis |
| Primary biliary cirrhosis |
| Systemic lupus erythematosus |
| Wegener's granulomatosis |
| Hidradenitis suppurativa |
| Acne conglobata |
| Malignancy |
| Thyroid disease |
| Pulmonary disease |
| Sarcoidosis |
| Diabetes mellitus |
Currently there is no definitive treatment for pyoderma gangrenosum. In smaller lesions it may be appropriate to treat with local therapy alone, but in more established lesions additional systemic treatment may be required. A range of local therapy is described in the literature ranging from simple dressings to intralesional injections of steroids or cyclosporine. There seems to be greater consensus upon systemic therapy, many favour the use of oral Prednisolone at the adult dose of 40–120mg/day for an undetermined period before gradually reducing the dose. Other systemic regimes have been described such as pulsed Methylprednisolone in refractory cases, Phendimetrazine tartrate (clofazamine) or systemic antibiotics such as Rifampin, Tetracyclines, Vancomycin and Mezocillin in addition to immune suppressant such as Tacrolimus or Azathioprine [6].
4. Conclusion
This is a rare report of pyoderma gangrenosum occurring secondary to a burn. Surgeons should consider pyoderma gangrenosum as a differential diagnosis in patients with wounds that are rapidly ulcerating and deteriorating despite appropriate antibiotic therapy since surgical debridement may actually make a bad situation worse.
Acknowledgment
The patient listed was admitted to the Burns Unit and his consent was given for the use of the images in medical publications.
References
- . Pyoderma gangrenosum: clinical and experimental observations in five cases occuring in adults. Arch Dermatol. 1930;22:655
- . Pyoderma gangrenosum: a review. J Am Acad Dermatol. 1988;18(3):559–568
- . Skin ulcers misdiagnosed as pyoderma gangrenosum. N Engl J Med. 2002;347(18):1412–1418
- . Acute pyoderma gangrenosum does not require surgical therapy. Arch Fam Med. 1998;7(4):377–380
- . Pyoderma gangrenosum complicating bilateral mammaplasty. Br J Plast Surg. 2000;53(5):440–441
- . Pyoderma gangrenosum: a review. J Cutan Pathol. 2003;30(2):97–107
- . Pyoderma gangrenosum and related disorders. Adv Dermatol. 1989;4:51–65
PII: S0305-4179(06)00160-4
doi:10.1016/j.burns.2006.04.032
© 2006 Elsevier Ltd and ISBI. All rights reserved.
