Pyoderma gangrenosum: challenges and solutions

Abstract

Pyoderma gangrenosum (PG) is a rare disease, but commonly related to important morbidity. PG was first assumed to be infectious, but is now considered an inflammatory neutrophilic disease, often associated with autoimmunity, and with chronic inflammatory and neoplastic diseases. Currently, many aspects of the underlying pathophysiology are not well understood, and etiology still remains unknown. PG presents as painful, single or multiple lesions, with several clinical variants, in different locations, with a non specific histology, which makes the diagnosis challenging and often delayed. In the classic ulcerative variant, characterized by ulcers with inflammatory undermined borders, a broad differential diagnosis of malignancy, infection, and vasculitis needs to be considered, making PG a diagnosis of exclusion. Moreover, there are no definitively accepted diagnostic criteria. Treatment is also challenging since, due to its rarity, clinical trials are difficult to perform, and consequently, there is no "gold standard" therapy. Patients frequently require aggressive immunosuppression, often in multidrug regimens that are not standardized. We reviewed the clinical challenges of PG in order to find helpful clues to improve diagnostic accuracy and the treatment options, namely topical care, systemic drugs, and the new emerging therapies that may reduce morbidity.

Keywords: biologics; neutrophilic dermatosis; pyoderma gangrenosum; treatment.

Figure 1

(A) Ulcerative stage of a pyoderma gangrenosum lesion, showing the typical violaceous, raised undermined border, with a granulation base, surrounded by a erythematous halo. (B) Healing stage, after 4 days therapy with systemic corticosteroids and cyclosporine, showing a decrease in the surrounding inflammation.

Figure 2

(A) Ulcerative stage of classical and rapidly progressive pyoderma gangrenosum ulcer, showing an elevated, violaceous, undermined border, with a necrotic and hemorrhagic base. (B) The healing stage ulcer, 3 months after systemic therapy, presenting the “Gulliver” sign; ulcer base containing granulation tissue, and necrotic tissue in a lesser extent.

Figure 3

Characteristic cribriform scar after healing of pyoderma gangrenosum.

Figure 4

Bullous variant of pyoderma gangrenosum, in a patient with acute myeloid leukemia, presenting overlap features with bullous variant of Sweet’s syndrome.