Behcet's disease (BD) is a multisystemic inflammatory vasculitic disorder which diagnosed by clinical criteria because of the lack of specific laboratory test and/or pathognomonic histopathological findings. The most frequent diagnostic criteria of this disease are mucocutaneous lesions, appearing at the disease onset or during the course, usually begin before significant organ dysfunction. According to BD International Study Group Criteria, one of the five criteria is dermatologic findings including pseudofolliculitis, acneiform nodules or papulopustular lesions (PPL) diagnosed by clinician in postadolescent patients. In some case reports and clinical studies, the PPL of BD are also denoted as Behcet's pustulosis, folliculitis, acneiform eruptions and pseudofolliculitis. Owing to implementation of follicular lesions in these criteria, there may be difficulties in the distinction between most of the PPL of BD and the other acneiform eruptions/nonspecific follicular lesions (e.g., acne vulgaris, bacterial folliculitis, steroid acne). Certainly, clinicians should distinguish these patterns for accurate diagnosis. Although earlier studies involve numerous quandaries regarding the diagnostic histopathologic pattern of BD (e.g., whether to include vasculitis or nonspecific folliculitis), it was reported recently that the determination of vasculitic changes in histopathological and direct immunofluorescence results might be useful in the differential diagnosis of patients suspected to have BD.