Pediatric emergency medicine trisk 323

TABLE 67.1
ACUTE VESICULOBULLOUS DISEASES INVOLVING PALMS AND
SOLES
Child <3 yrs old
Scabies
Acropustulosis of infancy
Syphilis (transiently at birth)
Adolescent or older
Tinea pedis or manuum
“Id” reaction
Epidermolysis bullosa of hands and feet
Any age
Drug eruption
Friction blisters or burns
Dyshidrotic eczema
Vasculitis (e.g., Henoch–Schönlein purpura)
Frostbite

INHERITED BLISTERING DISEASES
Epidermolysis Bullosa
Epidermolysis bullosa (EB) is a group of inherited blistering disorders that tends
to present in infancy or early in life with localized or widespread blistering at
sites of friction ( Fig 67.4 ). The cleavage plane leading to blistering is
determined by specific mutations that lead to loss of function in the attachments
between the epidermis and dermis. There are now over 30 subtypes of EB
categorized under 4 major broad categories ( Table 67.2 ), so for the purpose of
this chapter, we will discuss general recognition of the condition.


FIGURE 67.3 A: Infant with mastocytoma on the neck. B: Same patient with another
mastocytoma demonstrating the Darier sign following vigorous rubbing of the lesion.

FIGURE 67.4 A patient with junctional epidermolysis bullosa and a large, chronic ulceration
of the right leg.

All subtypes of EB may present at or shortly after birth with variably sized
bulla and erosions at sites of friction or adhesion. They may affect all areas of the
skin and the mucosa, particularly the oral mucosa, making early feedings a
challenge due to pain. EB may also affect several other organs depending on the
subtype. Patients may be born with large areas of absent skin known as congenital
localized absence of skin (CLAS). Milia are also frequently seen at sites of
blisters, and erosions and may be present at birth. A hoarse cry may indicate
airway involvement and is seen more commonly with junctional EB subtypes.
Milder types may also present with localized blistering at birth, however some
patients may not present until they are adolescents or adults. Certain types of EB
simplex, for example, may not be diagnosed until the patients enter the army or
other occupations where they are required to walk for long distances and
subsequently develop blisters on their feet or use their hands in a repetitive
motion leading to blistering on the palms. Patients may have other associated


findings such as anonychia or dystrophic nails, and certain subtypes are
associated with other systemic complications such as muscular dystrophy, pyloric
atresia, or photosensitivity. Over time, severe subtypes may mitigate, and milder
subtypes can become more severe. Mode of transmission varies depending on the
subtype, therefore family history may be useful in making the diagnosis.
The differential diagnosis of EB in the newborn period includes infections such
as herpes simplex virus (HSV), varicella (VZV) and bullous impetigo, and
cultures should be obtained to rule out an infectious etiology. Epidermolytic
ichthyosis, also known as bullous congenital ichthyosiform erythroderma, is a
rare, autosomal dominant ichthyosis caused by mutations in keratins 1 and 10

found in the epidermis and presents with widespread superficial blistering and
erythroderma in the neonatal period that can be confused with EB. The flexures,
palms, and soles are most commonly involved, and mucosal surfaces are spared.
With time, the skin develops thick, corrugated-like scale likely as compensation
for the blistering, which helps to clinically differentiate it from EB.
Diagnosis is made by skin biopsy using immunofluorescence antigen mapping
(IFM) and/or transmission electron microscopy (TEM) on newly induced blisters
to detect the location of blistering and which cellular attachments are disrupted.
However, genetic testing via mutation analysis is becoming first line as inducing
new blisters can be challenging, especially in the newborn period. Additionally,
mutation analysis allows for specific subclassification, which is important for
prognosis and genetic counseling.
In the emergency setting, the most important part of managing patients with
possible or known EB is handling the patients with care. This includes limiting
palpation only to areas of concern and avoiding adhesives as much as possible
(this includes adhesives for intravenous lines, nasogastric tubes,
electrocardiogram leads, etc.). Due to the numerous open areas of skin, EB
patients are at high risk for skin infection and frequently become infected (as well
as colonized) with Staphylococcus aureus and Pseudomonas aeruginosa. Areas
concerning for infection should be cultured and treated. If the patient is acutely
ill, they should be managed as needed in the acute setting with attention to skin as
secondary. Once stable, dermatology consultation is warranted, and further
wound care recommendations may be provided. For more information about EB,
visit www.debra.org .


TABLE 67.2
EPIDERMOLYSIS BULLOSA SUBTYPES