Epidermolysis Bullosa is a group of genetically inherited diseases in which the patient shows an enhanced tendency to develop blisters on areas subjected to a minor trauma.
These diseases are also called mechano-bullous diseases.
The blisters are usually situated on pressure points such as the toes, fingers, ankles, knees, wrists and elbows and occasionally on the face as well. Areas of the body having a bone underlying the skin are the most frequently involved sites.
These blisters tend to heal rapidly unless they are subjected to repeated trauma or if they develop secondary infection. Some patients show ulceration of the mucous membranes and defective development of the nails.
There are at least 14 types of epidermolysis bullosa classified into 3 groups on the basis
- Clinical features
- Mode of inheritance
- Level of split formation in the skin
Inherited as an autosomal dominant trait. They are characterized by the formation of splits in the epidermis by the degeneration of prickle or basal cells. These include:
Recurrent epidermolysis bullosa
- This occurs in the hands and feet.
- The disease starts during late childhood or adult life
- The blisters are limited to the palms and soles only
- There is worsening in summer.
Epidermolysis bullosa simplex
- This can start soon after birth.
- Blisters occur on traumatized sites throughout the body
- Mucosal and nail changes are minimal
- Healing occurs without scars.
Epidermolysis bullosa simplex herpetiformis
- Blisters appear early and are generalized
- The lesions tend to occur in herpetiform pattern
- There is spontaneous recovery during fevers.
Epidermolysis bullosa simplex
- It is associated with small hypo and hyperpigmented macules
- Later in life, the skin become atrophic and gets easily bruised.
- Palmo-plantar keratoderma may be associated.
- It occurs predominantly on the distal parts of extremities
- It is associated with easy bruisability and worsening in summer.
These are characterized by the formation of splits through the lamina lucida layer of skin deficient in hemidesmosomes. It has autosomal recessive inheritance and tendency to heal without scarring or milia formation. This group includes;
Epidermolysis bullosa atrophicans gravis
- It is almost uniformly fatal
- It characterized by severe blistering all over the body including the oral, gastro-intestinal, respiratory, uro-genital and conjuctival mucosae.
- The nails may be lost and the teeth may be dysplastic.
Epidermolysis bullosa atrophicans mitis
- it has an involvement of skin, oral mucosa and nails without the involvement of other organ systems
- Improvement occurs as the child grows older.
Epidermolysis bullosa atrophicans inversa
- In this type the blistering gets localized to the proximal parts of the extremities and the intertriginous areas of the perineum, axillae and neck.
- The traditional pressure sites are spared.
Epidermolysis bullosa atrophicans localisata
- The lesions are localized to the lower extremities and soles
- Aggravations occurs in summer
- Onset occurs at school going age.
Epidermolysis bullosa progressiva
- As the name suggests the severity increases with age
- Age of onset is 5 years
- Nnail changes occur before the skin lesion.
This include the types in which the blistering occurs below the basement membrane due to defective anchoring fibrils or by their dissolution due to an excess of collagenase.They occur both in autosomal dominant and recssive forms. These types are associated with severe scarring and milia formation.
Recessive epidermolysis bullosa dystrophica
- It has got severe blistering and scarring all over the skin, oral mucosa, conjunctiva and cornea, eosophagus, trachea, urethra with strictures.
- Loss of nails,
- Cicatrical alopecia (Baldness)
- Loss of teeth
Recessive epidermolysis bullosa dystrophica inverse
- the lesions are localized to intertriginous areas such as groins, axillae, neck, trunk and perianal area.An intertriginous area is area where opposing skin surfaces touch and may rub, such as skin folds of the groin, axilla and breasts.
Dominant epidermolysis bullosa dystrophica
- It involves the skin on the traumatized sites
- Scarring and milia formation
- Oral mucosa, nails, cornea and conjunctiva are involved
Dominant epidermolysis bullosa dystrophica-Albo-papuloid
- Skin coloured or whitish papules appear on the trunk at about puberty in addition to the blisters, scarring and milia which occur since birth.
Other varieties are quite rare.
The mainstay of treatment in all these cases is to protect the individual from trauma.
Care has to be taken to protect the patient even from those minor trauma which occur during one’s daily activities and which as a rule, go unnoticed, but the intensity of these measures will depend upon the severity of the disease.
During infancy, the patient has to be handled very gently.
The clothes have to be soft, padded and loose and should not produce friction at any site, and as the child grows, he should avoid activities likely to expose him to trauma. The blisters may be punctured but the roof of the blister must not be removed.
The dressings or the clothes should not be allowed to stick to the skin lesions and removed very gently.
Adhesive tapes should never be applied on the skin.
Topical and systemic Therapy
- Antibiotics may be used to prevent or treat infections.
- Vitamin E in a dose of 100 mg once or twice a day has been used in the epidermolytic type of epidermolysis bullosa simplex
- Phenytoin 2-4 mg per kg body weight a day has been used for the dermolytic types with good results.
These drugs bring about only a decrease in the severity of the disease.
Systemic corticosteroids may also be used for short periods to tide over difficult phases of the disease.