Bullous pemphigoid BP lecture

2021-03-24 12:00 AM

Usually begins with urticaria or papules, less dermatitis, eczema precedes the bladder for weeks or months, and then blisters spread to many places.

Outline

Bullous pemphigoid (BP) is a benign bullous skin disease occurring in the skin and mucous membranes, an unknown aetiology, with an autoimmune disorder with autoantibodies to IgG around lamina lucida and basal membrane of the epidermis, progressing chronic.

Uncommon disease, usually occurs in people over 60 years old, however, there are a few cases in children.

Pathogenesis

The cause is not clear.

The factor that incorporates HLA is unknown.

The BP antigen located on the cell surface stretching on the lamina lucida of the cell membrane combines with autoantibodies, with the participation of a complement that causes an inflammatory response that attracts polymorphonuclear leukaemia and eosinophils, there is an action and protein phenomenon leading to destruction of the basal membrane, splitting the epidermis, causing burns of water under the epidermis.

Some drugs can induce Pemphigoid.

Some drugs can cause bullous Pemphigoid in combination with malignancies inside the body.

Clinical symptoms

Usually begins with urticaria or papules, less dermatitis, the eczema precedes the bladder for weeks or months, and then blisters spread to many places.

The lesions are often distributed in many places, the most common locations are: lower abdomen, inner thighs, groin, armpits, forearm folds, lower leg chalk (usually first appearance).

The most characteristic lesions of bullous Pemphigoid are large, stretchy blisters that grow on an inflamed red background or on normal skin. Because it is bullous, it burns water under the epidermis, so it is usually intact without being broken, often stretched, firm. Fluid-filled bullae, sometimes haemorrhagic, when ruptured into a scaly-filled area, these plumes do not tend to spread around like Pemphigus and generally heal without scarring.

Nikilsky skin mark (-). The bullae are round, oval, arranged in an arc, round or zigzag shape, scattered individually, localize a region or spread, difficult to rupture, and cause less pain.

There are also red inlays, urticaria plaques and bullae appearing on it.

Mucosal injury is rare (8-39%), if any, it is usually a small blister in the mouth, difficult to rupture, less painful.

Symptoms of itching vary from non-itchy to severe itching.
Systemic symptoms are only present when the disease is severe, with widespread skin damage.

Clinical forms

There are a few less common clinical variants of BP.

Pemphigoid warts: there are plaques, pus in the armpit like Pemphigus warts.

Instrument Pemphigoid: there are scattered keratoses and keratinous plaques on blister, definitive diagnosis must be based on clinical and direct immunofluorescence.

Test

Histopathology

Subcutaneous blistering, inflammatory infiltrates of the dermis consisting of eosinophils, mononuclear and polymorphonuclear leukocytes, lymphocytes. Polymorphonuclear leukocytes line up one by one at the junction of the epidermis and dermis.

Pathological immunity

Direct immunofluorescence of nearly 90% of patients has IgG deposition, in nearly 100% of cases with C3, and IgG and C3 deposition along the basal membrane are typical for BP and some burns.

Indirect immunofluorescence 70% of patients with active BP have antibodies against the basilar membrane circulating.

Hematology

Peripheral eosinophilia 50% of patients.

Increased IgG in 70% of patients.

Diagnosis

Diagnosis is clinically confirmed by lesions such as large, tight, unbreakable blisters that grow on the background of inflammatory red or normal skin, patients 60 years of age and older, histopathology and immunofluorescence.

Differential diagnosis with:

Epidermal cup burns infected water.

 Duhring – Brocq desease.

Pemphigus.

Allergy to bullous drugs.

Evolution

Progression varies depending on the case: localized or diffuse, remission followed by relapse.

Treatment

In place:

Apply antiseptic gauze if the lesion erupts, apply antibiotic ointment, and corticoid fat when the lesion is dry.

Systemic treatment:

Corticoid starting with a dose of 40-100 mg/day using 2-3 weeks shows that 70-80% of the response is good after gradual dose reduction and maintenance dose.

Combination of corticosteroids with immunosuppressants (Azathioprine, cyclophosphamide, methotrexate, chlorambucil), especially in patients who do not respond to corticosteroids after 6-8 days of treatment. When the clinical response is good, the dose of both types is reduced, followed by the maintenance dose with corticosteroids alone.

In mild cases can use Sulfones (dapsone, DS) 100 - 150 mg / day usually respond after 2 weeks.

There are reports that the effective combination of nicotinamide Tetracycline in some cases.

If there is itching give Atarax (hydroxyzine).

Avoid scratching and ultraviolet rays.

Some suspected drugs should be avoided.