Pemphigoid
D E F I N I T I ON
An autoimmune subepidermal blistering (bullous) disease of the skin.
AET IOLOGY
Autoantibodies are formed against the basement membrane hemidesmosomal
glycoproteins BP180 and BP230. Serum levels of anti-BP180 antibodies (present in
65%patients) correlate with disease activity. MHC class II allele DQB10301 is a marker
for enhanced susceptibility to this disorder, possibly by facilitating presentation of BP180
proteins to T cells. Anti-BP230 antibodies may form as a consequence of keratinocyte
injury. Deposits of polyclonal IgG and complement at the junction of the dermis and
epidermis result in activation of the complement cascade, release of proteolytic enzymes
and destruction of the basement membrane. Mast cells appear to play an integral role in
this process.
Drug-induced bullous pemphigoid may be caused by penicillamine, furosemide, captopril,
penicillin, sulfasalazine. Most causative drugs contain sulfhydryl groups that cleave
epidermal intercellular substance, resulting in the production of the antibodies.
E P IDEMI OLOGY
Incidence of 4.3 per 100,000 person-years was found in a populationbased
study from the United Kingdom. Median age at presentation was 80 years. More cases
occur in women than men (60 % versus 40 %).
H ISTORY
Acute onset. The tense blisters are tender and can be very itchy.
New blisters can keep developing without adequate treatment.
EXAMI N A T ION
Primary lesions are often erythematous and eczematous plaques, generalized
on trunk and limbs. Large tense blisters then develop on these sites. (‘Cicatricial’
pemphigoid: Heals with scarring and may affect the eye and orogenital mucous membranes.)
I N V E S T IGATIONS
Skin biopsy:
A delicate 4-mm punch biopsy from the edge of an intact bulla: for light microscopy, to reveal
the ‘subepiderma’l blister.
A second biopsy for direct immunofluorescence (plus a biopsy of normal skin taken a few
millimeters from an involved area placed in Michel’s fixative). Deposits of IgG and
complement are seen in a linear pattern along the basement membrane zone.
MANAGEMENT
Topical corticosteroid therapy e.g. clobetasol propionate cream.
Patients with disease affecting mucous membranes who cannot be treated topically are
treated with oral corticosteroids and steroid-sparing agents.
In patients with extensive involvement: management of fluid loss, pain, temperature control,
and septicemia.
COMPL I C A T IONS
Fluid and electrolyte loss, secondary infections, complications of steroids
(diabetes mellitus, hypertension, gastric ulceration, osteoporosis).
P ROGNOS I S
Good. Control of pemphigoid is easier than that of pemphigus. Complete
remission after 1 year is common.
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