Diagnosis of<unk>  is challenging owing to its variable presentation, clinical overlap with other conditions, association with several systemic diseases, and absence of defining histopathologic or laboratory findings. Misdiagnosis and delayed diagnosis are common. It has been shown that up to 39% of patients who initially received a diagnosis of<unk>  have an alternative diagnosis. In light of this, validated diagnostic criteria have recently been developed for ulcerative<unk> . Diagnostic criteria In addition to a biopsy demonstrating a neutrophilic infiltrate, patients must have at least 4 minor criteria to meet diagnostic criteria. These criteria are based on histology, history, clinical examination and treatment. * Histology: Exclusion of infection (including histologically indicated stains and tissue cultures) * Pathergy (ulcer occurring at sites of trauma, with ulcer extending past area of trauma) * Personal history of inflammatory bowel disease or inflammatory arthritis * History of papule, pustule, or vesicle that rapidly ulcerated * Clinical examination (or photographic evidence) of peripheral erythema, undermining border, and tenderness at site of ulceration * Multiple ulcerations (at least 1 occurring on an anterior lower leg) * Cribriform or “wrinkled paper” scars at sites of healed ulcers * Decrease in ulcer size within 1 month of initiating immunosuppressive medications
Pyoderma gangrenosum
Ecthyma gangrenosum
Pseudomonal pyoderma
Helicobacter cellulitis
Streptococcal intertrigo
Epidermolysis bullosa
Tuberculous cellulitis
Hospital furunculosis