Immunobullous
(blistering) diseases of the skin are
autoimmune disorders. Any autoimmune condition
involves the immune system “attacking”
its own organs or tissues by producing autoantibodies
(antibodies against the self). In the skin, there
are proteins that attach epidermal cells to each
other and proteins that attach the epidermis to
the dermis. These proteins are the glue that keeps
the skin intact. When these proteins are damaged
by autoantibodies, the cells separate from each
other and a blister appears. The two main forms
of immunobullous disease of the skin are Pemphigus
and Pemphigoid.
Pemphigus presents as blistering
and raw sores inside the mouth or on the skin.
In some people, both locations are affected. Pemphigus
is derived from the Greek word pemphix meaning
bubble or blister. In Pemphigus, autoantibodies
attack proteins that connect each epidermal cell
to each other. There are three main types: pemphigus
vulgaris, pemphigus foliaceus,
and paraneoplastic pemphigus.
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Pemphigus
vulgaris most commonly occurs in people between
the ages of 40-60, often of Jewish or Mediterranean
descent. Pemphigus vulgaris most often affects
the inside of the mouth. |
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Pemphigus
foliaceus is characterized by crusty sores
that often begin on the scalp, and may move
to the chest, back, and face. It is not as
painful as pemphigus vulgaris, and is often
mis-diagnosed as dermatitis or eczema. |
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In
paraneoplastic pemphigus, painful sores appear
on the mouth, lips, and the esophagus. This
type of pemphigus is associated with underlying
cancer. Paraneoplastic pemphigus usually results
in fatal destruction of lung tissue (bronchiolitis
obliterans). |
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The
diagnosis of any pemphigus variant relies
on visual examination of skin lesions, skin
biopsy which must include direct immunoflourescence
examination. |
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If
not treated, pemphigus can be fatal, due to
overwhelming systemic infection and fluid
losses through the skin. Pemphigus can cause
scarring in severe cases, or when secondary
infections occur. |
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The
most common treatment is the administration
of oral corticosteroids, usually prednisone,
in conjunction with “steroid sparing”
agents or immunosuppressants. These drugs
quiet the immune attack so that blistering
stops and sores can heal. |
There are two major forms
of Pemphigoid, Bullous Pemphigoid
and Mucous Membrane (Cicatricial) Pemphigoid.
The type of Pemphigoid one has depends on the
autoantibodies that are present.
Bullous Pemphigoid
(BP) is a blistering disease of the skin
caused by autoantibodies directed against skin
proteins that connect the epidermis and the dermis.
BP causes blisters, itching and sometimes pain.
The majority of patients with BP experience remission
within five years of initial diagnosis, but sometimes
the disorder relapses. BP can often be treated
with a combination of topical steroids and non-steroidal
medications, but there are cases in which treatment
with oral corticosteroids or immunosuppressants
is required because of more severe or widespread
blistering. BP blisters usually heal without scarring.
Good wound care is important to promote healing
and prevent infection and scarring.
Mucous Membrane
Pemphigoid (MMP or Cicatricial pemphigoid)
is a blistering disease than can arise on any
mucous membrane surface including the nose, mouth,
eyes, esophagus, larynx, urethra and anal mucosa.
Scarring commonly occurs in affected areas and
spontaneous improvements and remissions are rare.
The affected organs dictate what treatment should
be used. Systemic steroids are generally not adequate
to control progression of MMP. Dapsone is drug
that can be helpful in less severe cases of MMP.
Azathioprine, mycophenolate mofetil and cyclophosphamide
are immunosuppressant medications that are used
in severe cases of MMP. It is important to treat
this condition promptly to avoid scarring. Sometimes
it is difficult to make the initial diagnosis
of MMP; more than one biopsy may be needed to
confirm the diagnosis and implement appropriate
therapy.
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