The Role of Collagen IV and Cytokeratin 5/6 Immunohistochemistry in Identifying Subtypes of Hereditary Epidermolysis Bullosa.

Hereditary epidermolysis bullosa (EB) constitute a genodermatosis group with variable clinical severity. Biopsies diagnosed as EB in the last 4 years were retrieved from the database of the king Khalid University Hospital and military hospital lab at Saudi Arabia. The current study was performed to examine the diagnostic usefulness of immunohistochemistry, as compared with electron microscopic examination, for subclassification of HEB. Fourteen cases were studied. Collagen IV immunostain was located above the blister in all dystrophic EB cases, and below the blister in all cases of epidermolytic and junctional EB. Cytokeratin 5/6 was visible above the blister in all cases of dystrophic and junctional types EB. In 2 out of 4 cases of epidermolytic EB, cytokeratin 5/6 was seen only above the cleft, whereas 1 case revealed positivity above and below the blister. One epidermolytic EB case showed scattered fragments of keratinocytes inside the blister.