[Immunohistochemical evidence of chronic inflammation in acne vulgaris]

The etiology and pathogenesis of acne vulgaris are not yet completely understood. Therefore we have investigated 5 patients with different clinical forms of disease, including the rare form of acne fulminans. Taking into consideration the four factors that are currently incriminated in the development of acne, sebaceous hypersecretion, hyperkeratosis of the pilosebaceous infundibulum, bacterial colonisation and perifollicular inflammation, we have focused our study on a set of cells involved in the chronic inflammatory process. We have evidenced by immunohistochemistry methods, using appropriate monoclonal antibodies, the presence of T lymphocytes and macrophages, while the B cells could be evidenced only in the severe forms. We were also interested to investigate the occurrence of new capillary formation, as an accompanying phenomenon of the inflammatory process. The presence and histological distribution of these cells highly supports the hypothesis that the mechanisms underlying the development of acne vulgaris belong to the Delayed Type Hypersensitivity.