EBSimplex Herpetiformis
Dowling-Meara
Increasing recognition of this disorder is making it clear that this is a
commoner type of EB Simplex than was previously believed.
Clinically, it generally causes blistering with an onset in early
infancy. There is a great range of severity in individual cases.
Blistering may be exceptionally severe during the neonatal
period, and these babies can present a devastating picture. Death
in the neonatal period is probably not infrequent, and in the
past many of these severe cases were probably thought to have
lethal Junctional EB. A rather characteristic thickening of the
nails is also commonly seen in Dowling-Meara EBS. Even in the
neonatal period, involvement of the hands and feet is prominent,
and is often already associated with nail thickening. Blisters
frequently occur at other sites on the face, trunk and limbs, and
tend to be disposed in groups. Of these other sites, the neck is
particularly commonly affected. A major provocative factor
appears to be friction from the seams of clothing. However, in
this condition, groups of blisters may appear with remarkably
little provocation. High environmental temperatures seem to be of
great importance in reducing the threshold for blistering. trike
other types of EB Simplex, secondary infection is very common and
is perhaps more of a problem in this than any other form.
Prognosis Generally, the prognosis in EB Simplex
is good, particularly in the common Weber-Co7ckayne type, the
great majority of patients having a normal life expectancy.
However, disability can be significant, patients' choices of
career, housing, employment and leisure activity being
constrained by limitations on the distance they can walk. While
the Dowling-Meara type of EB Simplex can undoubtedly be lethal in
early infancy, the blistering tendency tends to improve with
time, and some adults who had problems with the condition as
children later become more or less free from any evidence of the
disease. However, other adults remain substantially disabled by
Dowling-Meara EBS throughout their lives, particularly as a
result of persisting blistering of the hand and feet.
Techincal overview by Prof A Hovanian
Epidermolysis bullosa simplex (EBS) is a group of epidermal blistering
diseases almost invariably transmitted as a dominant trait, which has
recently been shown to arise from mutations in keratins 14 and 5
(K14 and K5). We describe a family with recessive EBS in which the
disease is tightly linked to the substitution of the highly conserved
glutamic acid-144 to alanine in the first helical segment of the rod
domain of keratin 14. In contrast, linkage with keratin 5 was excluded.
The loss of an ionic interaction with keratin 5 is likely to affect
K14-K5 heterodimer formation. Our data suggest that this mutation
underlies EBS in our family, and that mutations in keratin genes may
impair the mechanical integrity of basal keratinocytes in a recessive
as wellas dominant fashion.
Debra UK
From a new DEBRA publication, Epidermolysis
Bullosa: an Outline for Professionals, which is now arailable
from DEBRA. This new
publication has been adapted by Dr. David Atherton and Jacqueline
Denyer from a chapter written for "Textbook of Paediatric
Dermatology" published by Blackwell science.
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