EB simplex is the most common form of the condition. It is almost completely autosomal dominant inherited. The progressive form is usually mild; in childhood there is usually more blistering later, but the tendency remains lifelong. The healing of the blisters which develop intra-epidermally is normally without scarring or skin atrophy. Blistering happens mostly on the exposed areas, such as hands, feet, elbows, knees, etc., and is usually more during the summer months. Nails, mouth, mucous membrane and teeth are not affected, as can happen in other forms of EB (cf. Netzwerk EB 2009; EB Info World 2012).

This form of the condition is inherited autosomal recessively. Here there is a separation along the lamina lucida of the basement membrane, so that there is no cohesion between the epidermis and the dermis.

Depending on the severity of JEB, the progress can vary between minimal blistering and life-threatening limitations of skin function. Usually, the blisters heal without scarring, but due to secondary infections scarring can occur, and this may lead to atrophy of the skin in further progress of the condition. Typically, this skin atrophy develops on hands, elbows, feet and knees, and there may be dystrophic changes to the nails. Anomalies of the teeth, alopecia and pigmented (birthmark) may also occur (cf. Netzwerk EB 2009; EB Info World 2012).

This form of the condition is mostly inherited autosomal recessively. Usually there is scarring because the blistering is below the lamina densa, where the blood vessels and nerves are. Because of this the blisters can be very deep, contain blood and are painful. The blistering occurs as a result of injury, but it appears that sometimes it may be spontaneous. The clinical signs may vary considerably.

Scarring, milia (small white cysts) and nail dystrophy, and/or loss of nails are typical in this form of the condition. Usually, a flexor contracture of the fingers and a restriction of the abduction of the thumb develop.

Pseudosyndactyly may develop because the webbing grows between the fingers and toes; these may even go so far that the fingers and toes become mitten-like. Furthermore, there are often mutilations of the fingers and toes. The real cause of the pseudosyndactyly and mutilations are yet unknown.

The mucous membranes (especially in the mouth, the gastrointestinal and the urogenital tracts) are also affected in DEB.

The severity of the progress varies according to the subgroup from mild (usually in the dominantly inherited form) to a completely dependent state with a reduced life expectancy (RDEB severe generalised; Hallopeau-Siemens).

Further complications can be deformity of the teeth, defective hair growth on the head, anaemia, a tendency to squamous cell carcinoma (after early adolescence) and delayed growth (cf. Netzwerk EB 2009; EB Info World 2012; Pschyrembel 2012).