[Immunolabeling methods in cutaneous histopathology. Principles and practical applications]

Immunohistochemical methods, introduced more than 40 years ago, represent a favourite technique in the histological diagnosis of cutaneous diseases. Their practical applications, that initially concerned merely auto-immune dermatoses, have spread over many other nosologic groups of skin pathology. The improvement of immunolabelling techniques and of reagents has rendered the immunohistochemical methods much more reliable and has contributed to their spreading. Enzymatic techniques, by virtue of their advantages over fluorescent techniques, are being used more and more frequently. The continuous production of new antibodies (polyclonal but mainly monoclonal) renders possible the immunohistochemical detection of the different cellular or extracellular, epidermal and dermal components of the skin. The main chapters of cutaneous pathology, aside from auto-immune diseases, that concretely benefit from immunolabelling techniques, concern: a) the diagnosis and histogenetic study of tumoural lesions, b) the diagnosis and classification of bullous diseases, c) infectious diseases.