Dystrophic EB

What causes Dystrophic EB (DEB)?

Every person has two copies of each gene, the gene mutation that causes EB can be in one or both genes in a pair. DEB can be inherited dominantly or recessively.

Dominant Dystrophic EB (DDEB) is generally a less severe form of the two, whereby blistering may be confined to hands, elbows and feet but can also be widespread. Scarring, milia (white bumps), abnormal or absent nails are all common. A normal lifespan is possible and a range of treatments are available to help with pain and itch. The chances of a child developing DDEB is 50%. Dominant EB means they’ve inherited one faulty gene from one parent, which becomes the dominant gene, whilst the other gene in the pair is normal.

Recessive DEB (RDEB) – (formerly Hallopeau-Siemens RDEB) – is considered one of the most severe forms of EB with widespread blistering, including internally, which can affect the eyes, throat, bowels and digestion making daily life very difficult. The fingers and toes can fuse together as a result of the scar tissue trying to heal the blisters. The chances of a child inheriting RDEB from carrier parents is 25%. Recessive EB is when the individual has inherited two faulty genes – one from each parent. Recessive EB is usually more severe than dominant types and can come as a complete shock as the parents can be carriers without displaying symptoms themselves.

Source: DEBRA International

What are the symptoms of DEB?

• Skin blistering is widespread from birth with significant fragility from minor skin trauma.
• Chronic wounds are frequent in areas of repeated blistering.
• From infancy, blistering is more marked on bony areas causing extensive scarring that can lead to flexion contractures of the large joints (joints that cannot be straightened).
• Progressive pseudosyndactyly (fusion of the fingers and toes), flexion contractures, and resorption of the bone of the end of the fingers and toes lead to mitten deformities of the hands and feet.
• Areas of ulcerated skin is common and can appear on one or both sides of body, but in particular on the inner lower leg, and the tops of the feet and ankles.
• The development of squamous cell carcinoma (SCC) is very common and a frequent cause of death increasing in incidence from the teen years onwards, arising in areas of repeated trauma, wounds, and scarring.
• Progressive scarring leads to microstomia (contracture of the mouth) and ankyloglossia (reduced movement of the tongue), which can result in dental overcrowding and malalignment, and the development of secondary caries (cavities). Oesophageal blistering and scarring are common and urethral strictures may occur.
• Scarring alopecia (hair loss) and crusting are common with increasing age.
• Nails are usually lost progressively during the first several years of life. Anaemia due to iron deficiency and inflammation is common as is osteopenia, osteoporosis, and vertebral fractures possibly due to reduced mobility, chronic inflammation, vitamin D and calcium deficiency, and pubertal delay.
• Cardiomyopathy may rarely arise.
• Renal impairment and failure may occur as a result of acute kidney injury, post-streptococcal glomerulonephritis), renal amyloid, or IgA nephropathy.
• Lack of sufficient nutrition is common owing to factors affecting eating, including oesophageal blistering, microstomia, and dental caries, in combination with increased metabolic demands due to chronic wounds, infection, and inflammation.

Treatments

There is currently no cure for EB, our work aims to change this. However, there are treatments available which help with the management of pain and itch.

We fund research projects aiming to find additional treatments as well as a cure, and our EB Support Team are committed to help people and carers deal with the challenges that EB brings.