Epidermolysis bullosa simplex

What is epidermolysis bullosa simplex?

Epidermolysis bullosa (EB) simplex is a rare inherited disorder in which the skin is fragile and blisters at sites of rubbing. It is mild in the usual form; blisters tend to be confined to the palms and soles, and are most troublesome during warm weather. In other types the blistering may be more generalised and occasionally blisters arise in the mouth. The most severe form is called EB simplex Dowling-Meara and those affected have more widespread blistering which does not vary according to the time of year.

EB simplex is different from other types of EB which include junctional, dystrophic and Kindler forms; if you have EB simplex then you will not go on to develop these other types of EB. EB simplex is not an infection, it is not contagious and it is not due to an allergy.

What causes epidermolysis bullosa simplex?

The top layer of skin (the epidermis) is composed of layers of cells. Each cell has an internal support system formed from proteins (keratins), giving it strength and shape. In EB simplex, there is a weakness in one of these proteins (usually type 5 or type 14 keratin, but very occasionally another protein called plectin), which causes affected cells to be less resilient to friction and to rupture when subjected to even minor physical stress. When the cells break, they separate from each other, fluid accumulates between them and a blister forms.

Weakness of the protein is caused by a minor abnormality (a mutation) in the gene responsible for producing that protein. A variety of such abnormalities have been identified in EB simplex, some of which are common amongst patients with the condition while other abnormalities are only found in individual families.

Leave a Reply

Your email address will not be published. Required fields are marked *