Pyoderma Gangrenosum: The Great Impostor
Aside from being elusive and difficult to diagnose, PG can be incited, activated, or spread through a process of pathergy.3 Pathergy is a skin condition in which a minor trauma such as a bump or bruise leads to the development of skin lesions or ulcers that may be resistant to healing. It can also lead to ulcerations at the site of surgical incisions.4
Although PG is not common, it is an instructive model that we can use to gain a holistic view (viewing the whole as more than the sum of its parts) of a complicated disease process resulting in chronic wounds. Dermatologic changes can be the first sign of an underlying medical condition, and the skin can act as a window5 to a patient’s general health, guiding practitioners to a diagnosis.6 Patients may already have a preexisting diagnosis and go on to develop skin changes as part of multisystem disease.7 Categorized among the inflammatory dermatoses, PG is one of those diseases that herald underlying multisystem diseases or even a recurring preexisting comorbid condition, including rheumatologic, gastrointestinal, renal, and endocrine-metabolic disorders; internal malignancy (paraneoplastic skin changes)8; and/or hematologic cancers.
Any inflammatory or immune response associated with a given disease entity may result in a skin ulceration at a distant site that is static or even migratory. In PG, there is a propensity for lower-extremity ulceration. However, upper extremities and in some cases the abdominal wall, breast tissue, and other distant sites develop ulceration separate from the primary site or disease process. The etiology, pathergy, or triggering event is often unknown and remains an exclusionary diagnosis. The final standard pathway, however, is chronic inflammation as a result of an immune response.
In the management of PG, the clinician must be mindful of the multisystem approach, as highlighted in the continuing medical education article. While the treatment armamentarium is significantly focused on controlling PG with systemic and topical anti-inflammatory drugs, immunosuppressives, and antibiotics, it is important to consider that these patients may already be on therapeutic regimens for inciting comorbid diseases that triggered the predilection or risk for PG in the first place. Therefore, an interprofessional team including a clinical pharmacologist and pain management specialist is essential to manage the potential drug-drug, drug-disease, and drug-age interactions for patient safety, treatment efficacy, and quality consideration for harm/benefit and intention to treat.
Partnering with the patient is the “sine qua non” of what the patient wants and needs. Patients with PG and its complications require a focused interprofessional rehabilitation plan that takes into account the entire life span.1 As we all know, “Medicine has added years to life, but rehabilitation adds life to years.