Histological and immunofluorescence findings of non-follicular papulopustular lesions in patients with Behçet's disease

ABSTRACT Background Papulopustular lesions (PPL), the most common type of cutaneous lesions in Behçet's disease (BD), clinically may not be differentiated from ordinary acne. Disagreement exists as to the exact nature of these acneiform and folliculitis‐like lesions and whether to include them as a major criterion. Objective We investigated whether PPL can be a useful tool for the diagnosis of BD when non‐follicular lesions over the trunk or extremities were selected, and were correlated with histological and/or immunofluorescence study. Methods Seventeen patients with BD (five women, 12 men; mean ± SEM age, 32 ± 7.9 years), were enrolled in the study with blind histopathological and immunofluorescence studies. Biopsies of the PPL and adjacent (approximately 2 cm distant) normal‐appearing skin were performed from the extremities and trunk. Follicle‐based acneiform lesions and those lesions over face were excluded. Histological evaluation primarily included epidermal and dermal alterations, cellular infiltration and vascular changes. We also performed direct immunofluorescence studies, using polyclonal antibodies for IgA, IgG, IgM, C3 and fibrin. Results Lesional specimens of the patients with BD revealed a significant leucocytoclastic vasculitis as compared with non‐lesional skin (P