Epidermolysis bullosa is a heterogeneous group of chronic, hereditary, blistering disorders which range from a mild inconvenience to a disabling illness with significant mortality. Classification of this group of mechanobullous dermatoses is difficult because of the clinical overlap of the various clinical types of epidermolysis bullosa, and the lack of adequate clinical or laboratory criteria for their differentiation. The findings by light microscopy are variable; consequently, the various types of this disease are not easily discernible. With the aid of EM, more accurate diagnoses have resulted. Since Pearson''s detailed classification of these mechanobullous dermatoses by EM, there were few confirmations of the ultrastructural findings of epidermolysis bullosa. Because EM has not yet become readily available to everyone, published classifications based on these findings differ significantly and remain controversial.