Bullous Diseases Flashcards
3 most common bullous diseases
- bullous pemphigoid
- pemphigus vulgaris
- dermatitis herpetiformis
diagnosing bullous disease invollves:
skin biopsy for histopathology and immunofluorescence, as well as direct antibody testing
____ ____(BP) is a chronic autoimmune sub-epidermal blistering disease most frequently seen in the elderly.
bullous pemphigoid
explain the mechanism of BP
IgG autoantibodies bind to antigens that comprise the hemidesmosome adhesion complex in the basement membrane of the skin (BP180 or BP230).
This triggers complement activation and release of inflammatory mediators, resulting in the formation of local or generalized tense bullae.
The disease can occur on any, body surface, but mucous membrane involvement is rare.
in bp: ____ ____ bind to antigens that comprise the ____ adhesion complex in the _____ membrane of the skin (BP180 or BP230).
This triggers ____ activation and release of inflammatory mediators, resulting in the formation of local or generalized ____ bullae.
The disease can occur on any, body surface, but mucous membrane involvement is rare.
IgG autoantibodies bind to antigens that comprise the hemidesmosome adhesion complex in the basement membrane of the skin (BP180 or BP230).
This triggers complement activation and release of inflammatory mediators, resulting in the formation of local or generalized tense bullae.
The disease can occur on any, body surface, but mucous membrane involvement is rare.
____ should always be highly considered when tense bullae are present in patients older than 60 years.
BP should always be highly considered when tense bullae are present in patients older than 60 years.
compare and contrast BP and PV
BP rarely has mucosal lesions, as compared with pemphigus vulgaris, which frequently begins with oral erosions.
why is BP usually tense?
bulla is often intact because it’s a sub-epidermal blister– the full thickness of the epidermis comprises the roof of the blister
what would you see on an immunofluorescnece of a skin biopsy of someone with BP?
deposition of igG at the dermal/epidermal junction
treatment for BP
Therapeutic options depend upon the extent of the skin disease. Localized disease can be treated with potent topical corticosteroids. More extensive disease requires systemic corticosteroids (prednisone) in the short term in order to get the blistering under control.
Oral Doxycycline may be used as a steroid sparing agent once prednisone has blistering under control. Other immunosuppressive agents such as Methotrexate or Azothioprine are also options.
steroid sparing options for BP
Oral Doxycycline may be used as a steroid sparing agent once prednisone has blistering under control. Other immunosuppressive agents such as Methotrexate or Azothioprine are also options.
Pemphigus vulgaris is a chronic autoimmune blistering disease that can cause significant morbidity and serious complications. what genetic predispositions are there towards PV?
Pemphigus vulgaris is a chronic autoimmune blistering disease that can cause significant morbidity and serious complications.
There is a genetic predisposition for Ashkenazi Jews and certain HLA types
key feature of PV that distinguishes it from BP
firstly, Patients usually complain of painful sores in the mouth and bleeding of the gums when brushing their teeth. The oral cavity is frequently the first site of involvement, with painful skin lesions appearing months or years later. Other mucosal sites such as the nasal mucosa, throat, eyes, and genital areas may also have lesions.
Look for painful erosions and ulcers anywhere on the oral mucosa, but particularly on the hard and soft palate. The gingiva may have lesions in a “desquamative gingiva” pattern with marked erythema and peeling of the attached gingiva. It is rare to see intact vesicles or bullae in the oral cavity.
etiology/mechanism of pemphigus vulgaris
The etiopathogenesis is antibody-mediated cell damage, known classically as acantholysis and more recently as apoptolysis. A variety of antigens including desmoglein 1 and 3 (mucosal) are involved.
PV: The etiopathogenesis is antibody-mediated cell damage, known classically as ____ and more recently as ____. A variety of antigens including ___ 1 and 3 (mucosal) are involved.
The etiopathogenesis is antibody-mediated cell damage, known classically as acantholysis and more recently as apoptolysis. A variety of antigens including desmoglein 1 and 3 (mucosal) are involved.
bulla differences in BP vs PV
BP: tense because entire epidermis is the roof of the blister
PV: bulla are flaccid and break easily.
in PV:Lateral pressure on adjacent lesional skin or rubbing normal-appearing skin will extend the bullae or cause erosion, respectively. This is a positive ____ sign. Lesions will not remit without treatment and may become extensive.
Lateral pressure on adjacent lesional skin or rubbing normal-appearing skin will extend the bullae or cause erosion, respectively. This is a positive Nikolsky’s sign. Lesions will not remit without treatment and may become extensive.
in PV, what would you see on the histopathological slide and the immunofluorescent slide?
Histopathology shows Intraepithelial vesicles with acantholysis. The bullae rupture easily because of the immunologic deconstruction of the epidermis
Direct immunofluorescence exhibits “chicken-wire” deposition of IgG and C3 between keratinocytes
treatment for PV
Systemic immunosuppression is used if oral disease cannot be successfully managed with topical steroids, or if skin disease develops.
Systemic therapy such as Mycophenolate mofetil. IVIG or Cyclosporine however is more often required to treat pemphigus vulgaris
Newer studies have shown that rituximab* either alone or combined with intravenous immunoglobulin (IVIG) or prednisone may lead to durable remission for many patients with skin disease and allow patients to be discontinued from prednisone completely.
_____ ____ is a chronic pruritic autoimmune blistering disorder associated with gluten-sensitive enteropathy.
It most commonly affects patients of Northern European descent and occurs more frequently in ___ than ____.
Dermatitis herpetiformis (DH) is a chronic pruritic autoimmune blistering disorder associated with gluten-sensitive enteropathy.
Dermatitis Herpetiformis most commonly affects patients of Northern European descent and occurs more frequently in men than women.
Even those DH is a bullous disease, why are blisters often absent? where do you usually find the blisters?
Blisters are usually small, between 1 and 2 mm in diameter. Symmetrically grouped, extremely pruritic urticarial plaques with pinpoint vesicles over extensor arms, legs, scalp, and buttocks.
Because of the intense pruritus, blisters are often absent and instead multiple excoriations are more commonly seen as secondary morphology
treatment of DH
. Many patients who adhere to a strict gluten-free diet experience complete remission of their disease.
Dapsone, for more extensive disease, can be started at 25 mg p.o. daily with gradual increase to an average maintenance dose of 0.5-1.0 mg/kg p.o. daily. Dapsone will improve cutaneous disease but has no effect on intestinal involvement.
Dapsone however, may produce hemolysis, methemoglobinemia, a hypersensitivity syndrome, and peripheral neuropathy as known side effects and should be used with caution.
DH predisposes patients to which other diseases?
Patients with DH are at an increased risk of developing Hashimoto’s thyroiditis, Diabetes mellitus, and enteropathy associated T cell lymphoma, and therefore warrant close surveillance.
what would you see on histopathology of someone with DH?
collections of neutrophils at the top of the papillary dermis
