Understanding the zebras of wound care: an overview of atypical wounds.

Atypical wounds account for approximately 5% to 20% of chronic ulcerations. Typically, clinical suspicion of an uncommon etiology is warranted for wounds that do not show signs of healing with conventional care, that are associated with pain out of proportion to the clinical presentation, or that are atypical in appearance. This review provides a general overview of various atypical wound etiologies, clinical presentations and appearance, and current treatment protocols. The clinical presentation, pathophysiologic etiology, and current literature on each etiology are presented. The etiologies discussed are pyoderma gangrenosum, calciphylaxis, lichen planus, necrobiosis lipoidica, infectious ulcers, hidradenitis suppurativa, artefactual ulcers, hydroxyurea-induced ulcers, vasculopathies, and neoplastic ulcers. Patients with atypical wounds experience a poorer prognosis and slower healing rate compared with patients with typical wound etiologies (eg, vascular and diabetic wounds). Biopsy is often vital in wound care to identify and differentiate wound etiologies. It is important to note that multiple characteristics or histologic features can overlap in a biopsy with atypical wounds. Therefore, a biopsy will still require an understanding of the presentation of these different wounds and should only be used when appropriate. The proper diagnosis for an atypical wound can greatly hasten wound closure, decrease the cost for the patient and the health care system, and improve the patient's quality of life. Because of the limited availability of patient populations with atypical wound etiologies, literature concerning specific pathologies is limited. More research on each pathology is needed, as is a universally accepted treatment protocol for atypical wounds.