52: Pemphigus Flashcards
What is the primary difference in the location of blisters between Pemphigus Vulgaris and Pemphigus Foliaceus?
Pemphigus Vulgaris features blisters above the basal layer due to suprabasal acantholysis, while Pemphigus Foliaceus has blisters in the granular layer due to subcorneal acantholysis.
What are the common demographic characteristics associated with Pemphigus Vulgaris?
Pemphigus Vulgaris is more common in individuals of Jewish and Mediterranean descent, with a male-to-female ratio of 1.33:2.25 and an age of onset typically between 50-70 years.
What are the key clinical features of Pemphigus Vulgaris?
Key clinical features include flaccid blisters, erosions that spread at the periphery, mucosal involvement, and a positive Nikolsky sign.
What is the predominant IgG subclass found in both Pemphigus Vulgaris and Pemphigus Foliaceus?
IgG4 is the pathogenic and predominant IgG subclass found in both Pemphigus Vulgaris and Pemphigus Foliaceus.
What are the treatment options for Pemphigus?
Treatment options include corticosteroids, Rituximab, Azathioprine, Mycophenolate mofetil, Methotrexate, IVIg, and other immunosuppressive therapies.
What are the histopathological findings in Pemphigus Vulgaris?
Histopathological findings include intraepidermal blisters, suprabasal acantholysis, retention of basal keratinocytes, and sparse dermal inflammatory infiltrate with eosinophils.
What is the prognosis for patients with Pemphigus?
The prognosis can be chronic and relapsing, with long-term remission possible; however, it can be potentially fatal and is influenced by factors such as age and comorbidities.
A patient with pemphigus vulgaris has a poor prognosis. What factors contribute to this prognosis?
Poor prognostic factors include old age, comorbidities, and high levels of autoantibodies.
A 55-year-old Ashkenazi Jewish patient presents with flaccid blisters and painful mucosal erosions. What genetic marker is most likely associated with their condition?
The genetic marker most likely associated is HLA-DR4 (DRB1*0402 allele).
A patient from Brazil presents with endemic pemphigus foliaceus (fogo selvagem). What age group is most commonly affected by this condition?
Children and young adults are most commonly affected by endemic pemphigus foliaceus in Brazil.
A patient presents with scaly, crusted erosions on an erythematous base in a seborrheic distribution. What clinical sign would confirm pemphigus vulgaris?
The clinical sign that would confirm pemphigus vulgaris is a positive Nikolsky sign.
A patient with pemphigus vulgaris has mucosal involvement. Which mucosal sites are most commonly affected?
The most commonly affected mucosal sites are the nasal mucosa (76%), pharynx (66%), and larynx (55%).
A biopsy of a blister shows suprabasal acantholysis and a ‘row of tombstones’ appearance. What condition does this indicate?
This indicates pemphigus vulgaris.
A patient with pemphigus foliaceus has subcorneal pustules containing neutrophils. What layer of the skin remains intact?
The epidermis beneath the granular layer remains intact.
A patient with pemphigus vulgaris is treated with corticosteroids. What is the initial dosage and duration of treatment?
The initial dosage is 1.5 mg/kg/day of prednisone equivalent for 2-3 weeks.
A patient with pemphigus vulgaris is started on rituximab. What is the maintenance dosing schedule?
The maintenance dose is 500 mg at 12 months, then every 6 months, with 1000 mg if clinical relapse occurs.
A patient with pemphigus vulgaris is prescribed azathioprine. What is the target dose and monitoring protocol?
The target dose is 2.5 mg/kg/day, and blood and liver function should be monitored over the first 8-12 weeks.
A patient with pemphigus vulgaris is treated with mycophenolate mofetil. What is the maximum daily dose?
The maximum daily dose is 3 g/day, dosed twice daily.
A patient with pemphigus vulgaris is treated with IVIg. What is its mechanism of action?
IVIg functions by saturating the neonatal Fc receptor, increasing the catabolism of the patient’s serum antibodies.
A patient with pemphigus vulgaris has a chronic, relapsing course. What are the potential complications of this condition?
Potential complications include secondary infections, sepsis, and treatment side effects or comorbidities like hypertension.
A patient with pemphigus foliaceus presents with burning sensations and exacerbation on sun exposure. What antigen is targeted in this condition?
The antigen targeted in pemphigus foliaceus is Dsg1 (160 kDa protein).
A patient with pemphigus vulgaris has IgG4 antibodies. What is the role of these antibodies in the disease?
IgG4 is the pathogenic and predominant IgG subclass in both pemphigus vulgaris and pemphigus foliaceus.
A patient with pemphigus vulgaris has intercellular IgG and C3 deposition. What diagnostic test confirms this finding?
Direct immunofluorescence (DIF) confirms intercellular IgG and C3 deposition.
A patient with pemphigus vulgaris has IgG in a cell surface pattern on indirect immunofluorescence (IIF). What substrate is commonly used for this test?
The substrate commonly used is monkey esophagus.
