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.
A patient with pemphigus vulgaris has mucosal involvement. What ELISA test result would confirm this diagnosis?
An ELISA test showing Dsg3 (130 kDa) confirms mucosal involvement in pemphigus vulgaris.
A patient with pemphigus foliaceus has cutaneous involvement. What ELISA test result would confirm this diagnosis?
An ELISA test showing Dsg1 (160 kDa) confirms cutaneous involvement in pemphigus foliaceus.
A patient with pemphigus vulgaris is treated with methotrexate. What is the dosing schedule for this medication?
Methotrexate is used once a week.
A patient with pemphigus vulgaris is treated with plasmapheresis. What is the purpose of this treatment?
Plasmapheresis is used to remove pathogenic autoantibodies from the patient’s circulation.
A patient with pemphigus foliaceus has a seborrheic distribution of lesions. What histological feature is characteristic of this condition?
Histological features include subcorneal acantholysis and subcorneal pustules containing neutrophils.
A patient with pemphigus vulgaris has painful mucous membrane erosions. What is the most likely presenting sign?
Painful mucous membrane erosions are often the presenting sign of pemphigus vulgaris.
A patient with pemphigus vulgaris has a burning feeling of the skin. What environmental factor can exacerbate this condition?
Photoexacerbation can worsen the burning feeling of the skin in pemphigus vulgaris.
A patient with pemphigus vulgaris has a chronic course. What is the likelihood of long-term remission?
Long-term remission may occur in months to years.
A patient with pemphigus vulgaris has a suprabasal blister. What histological feature is seen in the basal keratinocytes?
Retention of basal keratinocytes along the BMZ gives a ‘row of tombstones’ appearance.
A patient with pemphigus foliaceus has hyperkeratosis and parakeratosis. What layer of the skin is affected?
The granular layer of the skin is affected in pemphigus foliaceus.
A patient with pemphigus vulgaris has a sparse dermal inflammatory infiltrate. What type of cells are predominantly present?
Eosinophils are predominantly present in the sparse dermal inflammatory infiltrate.
A patient with pemphigus vulgaris has a subcorneal blister. What type of acantholysis is observed?
Subcorneal acantholysis is observed in pemphigus vulgaris.
A patient with pemphigus vulgaris has a burning sensation in vulvar lesions. What symptom does this cause?
Burning with urination is caused by vulvar lesions in pemphigus vulgaris.
A patient with pemphigus vulgaris has a chronic course. What is the mortality risk if untreated?
Pemphigus vulgaris is potentially fatal if untreated.
A patient with pemphigus vulgaris has a positive Nikolsky sign. What does this indicate about the skin?
A positive Nikolsky sign indicates that the skin can be extended into visibly normal areas by pulling or rubbing at the periphery of active lesions.
What is the etiology of Pemphigus vegetans?
Pemphigus-Lupus overlap.
What are the clinical features of Pemphigus erythematosus (Senear-Usher syndrome)?
Crusted erosions in a seborrheic distribution, lupus-like discoid lesions with ‘carpet-tack’ scale, burning sensation, and exacerbation on sun exposure.
What histopathological findings are associated with Endemic pemphigus foliaceous?
Suprabasal acantholysis, papillomatosis of the dermal papillae, downward growth of epidermal strands into the dermis, presence of hyperkeratosis and scale-crust, and eosinophilic or neutrophilic intraepidermal abscess.
What are the Direct Immunofluorescence (DIF) findings in Pemphigus vegetans?
IgG on the cell surface of keratinocytes.
What is the ELISA testing result for Pemphigus erythematosus?
Dsg1.
What is the expected course of Pemphigus vegetans?
Better and milder course with higher chance of remission.
What are the treatment options for Drug-induced pemphigus?
Remission after stopping the offending drug; improvement of Pemphigus Vulgaris with cigarette smoking and cholinergic agonists (pyridostigmine, carbachol, pilocarpine).
A patient with pemphigus vegetans presents with excessive papillomatosis and crusting. What histological feature is characteristic of this condition?
Histological features include suprabasal acantholysis with papillomatosis of the dermal papillae and downward growth of epidermal strands into the dermis.
A patient with pemphigus erythematosus has lupus-like discoid lesions. What test result would confirm this diagnosis?
A positive lupus band test due to granular deposits of IgG and cleaved Dsg1 ectodomain deposited at the BMZ after UV light exposure would confirm the diagnosis.
A patient with drug-induced pemphigus is found to have consumed thiol-containing foods. What are examples of such foods?
Examples of thiol-containing foods include garlic, leeks, and onions.
A patient with pemphigus erythematosus has IgG and C3 deposition at the granular BMZ. What clinical feature is associated with this condition?
Clinical features include lupus-like discoid lesions with ‘carpet-tack’ scale.
A patient with pemphigus vegetans has eosinophilic intraepidermal abscesses. What clinical presentation is expected?
Clinical presentation includes excessive papillomatosis and crusting, often in intertriginous areas, scalp, and face.
A patient with drug-induced pemphigus is taking penicillamine. What is the mechanism of action leading to pemphigus?
Penicillamine interacts with sulfhydryl groups in Dsg1, Dsg3, or both, leading to pemphigus.
