[Atypical wounds: definition and classification]

Wound represents disruption of the anatomic and physiologic continuity of the skin. Regarding the healing process, wounds can be classified as acute or chronic wounds. A wound is considered chronic if healing does not occur within the expected period according to its etiology and localization. Chronic wounds can be classified as typical and atypical. Typical wounds include ischemic, neurotrophic and hypostatic ulcers and two separate entities: diabetic foot and decubitus ulcers. Eighty percent of chronic wounds localized on the lower leg are the result of chronic venous insufficiency, in 5-10 percent the cause is of arterial etiology, whereas the remainder is mostly neuropathic ulcer. Ninety-five percent of chronic wounds manifest as one of the above mentioned entities. Other forms of chronic wounds represent atypical chronic wounds, which can be caused by autoimmune disorders, infectious diseases, vascular diseases and vasculopathies, metabolic and genetic diseases, neoplasm, external factors, psychiatric disorders, drug related reactions, etc. Numerous systemic diseases can present with atypical wounds. The primary cause of the wound can be either systemic disease itself (Crohn's disease) or aberrant immune response due to systemic disease (pyoderma gangrenosum, paraneoplastic syndrome).