Epidermolysis bullosa simplex is a horrible skin blistering disease. It is genetic in nature. Specifically it results from mutation of a type of keratin subunit of intermediate filaments. Because the IFs of someone with this disease are so drastically impaired, their epidermis is not correctly anchored to their dermis (the layer of their skin aren't held together right). As a result, these patients develop severe blisters with even extremely soft contact, so shaking hands with them is NOT a good idea.