Pemphigus

Diagnosis

Indications for Testing

  • Presence of chronic, recurring bullae (blisters), erosive or crusting/scaling skin, and/or mucous membrane disease
  • After more common diseases have been ruled out

Laboratory Testing

  • Direct immunofluorescence (DIF) performed on perilesional skin biopsy
    • Immunohistology
      • Perilesional skin biopsy – cutaneous DIF submitted in Michel’s transport medium or Zeus fixative
        • Pemphigus vulgaris, vegetans, and foliaceus
          • IgG and C3 (third component of complement) are detected on cell surfaces (formerly referred to as intercellular substance) of epidermal and stratified squamous epithelial cells in and around affected skin areas
          • Location of IgG and C3 cell surface staining within epithelium may indicate subtype of pemphigus
            • Cell surface staining is typically around basal cells in pemphigus vulgaris and vegetans, whereait is higher in epithelium in pemphigus foliaceus
            • ELISA testing for desmoglein 1 and 3 antibodies may better distinguish pemphigus subtypes
        • Pemphigus erythematosus
          • Features of pemphigus and lupus erythematosus are present on histologic examination of formalin-fixed tissue and show cell surface antibodies with granular immune deposits at the basement membrane zone (BMZ) by DIF, with or without positive lupus serologies
        • IgA pemphigus (rare)
          • IgA (with or without C3) – detected on cell surfaces of epidermal and stratified squamous epithelial cells in and around affected areas
  • Initial serum testing – pemphigus panel, pemphigoid panel, and endomysial antibodies (all three tests for initial testing), or epithelial skin antibodies testing (see Lab Tests tab)
    • Broad epithelial antibody screening recommended unless a specific immunobullous skin disease type is suspected due to overlap in clinical presentations of immunobullous disease
    • Pemphigus types with IgG cell surface antibodies are more common than IgA pemphigus – ruling out IgG pemphigus prior to testing for IgA pemphigus is recommended
  • Serum IgG cell surface antibody testing
    • IgG cell surface antibodies detected in serum by indirect immunofluorescence (IFA) on intact human skin and monkey esophagus substrates
    • Testing for IgG cell surface and desmoglein antibodies is highly sensitive and specific for IgG pemphigus types
      • Up to 80% of pemphigus patients have IgG antibodies present in serum
        • Presence of IgG cell surface antibodies and desmoglein antibodies in serum correlates with disease activity in the most common types of pemphigus (pemphigus vulgaris and pemphigus foliaceus)
      • Useful for establishing the diagnosis of most pemphigus types
      • Can distinguish pemphigus from other immune-mediated skin disease, including other immunobullous diseases
      • Cell surface antibodies are pathogenic (not epiphenomena of the disease)
      • IFA is often positive in paraneoplastic pemphigus, showing cell surface antibody staining (desmoglein antibodies may or may not be positive)
      • Refer to Paraneoplastic Pemphigus topic
  • Serum desmoglein 1 and 3 IgG antibodies
    • Desmoglein 1 autoantibodies predominate in pemphigus foliaceus (likely pemphigus erythematosus)
    • Desmoglein 3 autoantibodies are present in pemphigus vulgaris (likely pemphigus vegetans)
    • Although predominant antibodies differentiate the subtypes of pemphigus, overlap may occur
      • Patients with both skin and mucosal lesions may have IgG antibodies to desmogleins 1 and  3
      • Predominant antibody may change over course of disease
    • Nondesmoglein antibody pemphigus has been described
      • For diagnosis, IFA and desmoglein 1 and 3 IgG antibodies testing is advised
  • Serum IgA cell surface antibody testing
    • Cell surface antibodies detected by IFA on intact human skin and monkey esophagus substrates
    • Testing for IgA cell surface antibodies is important in the diagnosis of IgA pemphigus
      • Testing is highly sensitive and specific
    • Can distinguish IgA pemphigus from other pemphigus variants and other immune-mediated skin disease

Differential Diagnosis

Monitoring

  • Both IgG cell surface antibodies by IFA and IgG desmoglein (desmoglein 1 and desmoglein 3) antibodies by ELISAs are useful in monitoring disease activity and response to therapy in IgG pemphigus types
    • Levels of IgG antibodies to desmoglein 1 and/or desmoglein 3 fluctuate with disease activity
      • Relative levels may change over time with associated clinical changes
  • IgA cell surface antibody by IFA – useful for monitoring disease activity and response to therapy in IgA pemphigus

Clinical Background

Pemphigus is an autoimmune blistering disease that affects epithelium, including skin and mucous membranes.

Epidemiology

  • Incidence - 1-5/million (Baum, 2014)
  • Age – all ages, including childhood; peak during 50s-60s
  • Sex – M:F, equal
  • Ethnicity
    • Pemphigus vulgaris is more common in patients of Ashkenazi Jewish or Mediterranean descent and is HLA-associated
    • Fogo selvagem (endemic pemphigus foliaceus) occurs in rural areas of Brazil, Columbia, and Tunisia

Types of Pemphigus

  • IgG pemphigus – most common
    • Pemphigus vulgaris (70%)
      • Spontaneous
      • Drug-induced
    • Pemphigus vegetans
    • Pemphigus foliaceus (20%)
      • Spontaneous
      • Drug-induced
      • Fogo selvagem
    • Pemphigus erythematosus (Senear-Usher syndrome)
    • Pemphigus herpetiformis
  • Paraneoplastic pemphigus
    • Typically IgG antibodies
    • IgA antibodies – rarely described
  • IgA pemphigus – rare, with two main subsets
    • Subcorneal pustular dermatoses
    • Intraepidermal neutrophilic IgA dermatosis

Pathophysiology

  • Association with HLA genotypes DRB1*0402, DRB1*1401, and DQB1*0302 in Caucasians and DRB1*14 and DQB1*0503 in Japanese, indicating that antibody production is T-cell dependent
  • Autoantibodies to cell adhesion proteins in epithelium cause separation or suprabasilar keratinocyte acantholysis
  • Eosinophil infiltration, including eosinophil-associated spongiosis and abscesses
  • IgG pemphigus – most common
    • Presence of serum IgG cell surface antibodies with demonstrated pathogenic activity (not simply as epiphenomena of the disease)
      • IgG epithelial cell surface antibodies (formerly known as intercellular substance antibodies) detected by direct immunofluorescence (DIF) in perilesional skin and/or mucous membrane
      • Limiting dilution serum titers correlate with disease activity
    • Major (but not exclusive) antigenic targets for pathogenic antibodies in certain types of pemphigus are desmogleins, which are cell adhesion components of desmosomes in keratinocytes
      • Desmoglein 1 IgG antibodies predominate in pemphigus foliaceus and pemphigus erythematosus
        • Associated with nonmucosal lesions
        • Detected by enzyme linked immunosorbent assay (ELISA)
        • Levels correlate with disease activity
      • Desmoglein 3 IgG antibodies predominate in pemphigus vulgaris and pemphigus vegetans
        • Associated with mucosal lesions
        • Detected by ELISA
        • Levels correlate with disease activity
      • Overlap occurs with antibodies to both desmoglein 1 and desmoglein 3; the relative predominance of antibodies may change over time
        • Testing for desmoglein 1 and 3 antibodies by ELISA is performed to monitor relative levels in association with disease activity and response to therapy
        • Correlation with IFA findings reveals changing antibody profiles
  • IgA pemphigus
    • Rare form of pemphigus (most pemphigus cases have IgG antibodies)
      • IgA epithelial cell surface antibodies detected by DIF of perilesional skin
    • Serum IgA cell surface antibodies detected by indirect immunofluorescence (IFA)
      • Subcorneal pustular dermatosis (SPD) type – vesicles and pustules in a subcorneal or upper epidermal location
      • Intraepidermal neutrophilic (IEN) IgA dermatosis type – pustules throughout the epidermis
  • Drug-induced pemphigus
    • Multiple drugs implicated
      • Some drugs may induce acantholysis without production of antibodies
      • Penicillamine and captopril have sulfhydryl groups that may interact with sulfhydryl groups in the desmogleins to modify their antigenicity or interfere with adhesion activities
    • Disease typically remits once drug use is discontinued

Clinical Presentation

  • General signs and symptoms
    • Flaccid blisters on face, scalp, upper body, and intertriginous areas
      • Nikolsky sign – applying pressure on blister periphery extends the lesion laterally
    • Mucosal lesions and erosions
  • Types of pemphigus
    • Pemphigus vulgaris – initial presentation is usually oral ulcers with mucosal involvement
      • Subsequent development of superficial flaccid blisters and erosions on the trunk, face, scalp, and proximal limbs, positive Nikolsky sign
    • Pemphigus vegetans – intertriginous and oral with involvement of tongue (cerebriform tongue)
      • Flaccid bullae and erosions (Neumann type)
      • Pustules (Hallopeau type)
    • Pemphigus foliaceus, including fogo selvagem – small superficial blisters typically on neck and upper trunk, "cornflake" scale as in seborrheic distribution
      • No mucosal involvement
      • Positive Nikolsky sign
    • Pemphigus erythematosus (Senear-Usher syndrome) – rare form of pemphigus with features of lupus
      • Variant of pemphigus foliaceus
      • Predisposition for the face
    • Drug-induced (may be either pemphigus vulgaris or foliaceus) – multiple drugs implicated
    • IgA pemphigus types (rare)
      • Pruritic vesicles and pustules with SPD (clinically similar to Sneddon-Wilkinson disease, but immunologically distinguishable)
      • Variable skin lesions with numerous pustules in IEN
    • Paraneoplastic pemphigus

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
Cutaneous Direct Immunofluorescence, Biopsy 0092572
Method: Direct Immunofluorescence
(Direct Fluorescent Antibody Stain)

Order concurrently with serum antibody testing and fixed tissue histopathology for assessment of patient with pruritic, urticarial, blistering and/or erosive disorders, including possible pemphigoid and pemphigoid variants, pemphigus and pemphigus subtypes, dermatitis herpetiformis, epidermolysis bullous acquisita, porphyria, and pseudoporphyria

Order concurrently with fixed tissue histopathology for assessment of patient with inflammatory, immune-mediated cutaneous disease, including possible lupus and lupus variants, vasculitis, drug reactions, lichen planus and lichenoid reactions

For skin involvement, biopsy perilesional skin

For mucous membrane involvement, biopsy nonlesional mucosa

See Immunobullous Skin Diseases Testing algorithm

May be inaccurate if tissue is taken from incorrect perilesional location (attached/intact epithelium or epidermis is required)

Not possible to reliably distinguish pemphigus subtypes based on direct immunofluorescence (DIF); serum testing is helpful for subtyping

Tissue must be submitted in Michel’s transport medium or Zeus tissue fixative; this test cannot be performed on formalin-fixed tissue

Initial concurrent and repeat serum testing with pemphigus panel and pemphigus IgA antibodies is the most sensitive testing for diagnosis, for determining pemphigus subtype, and following disease activity

Patients with indeterminate results should have repeat DIF biopsy

Patients with changing clinical features should have repeat DIF biopsy because antibody profiles may change over time

Pemphigus Antibody Panel - Epithelial Cell Surface Antibodies and Desmoglein 1 and Desmoglein 3 Antibodies, IgG 0090650
Method: Enzyme-Linked Immunosorbent Assay/Indirect Fluorescent Antibody

Preferred panel for initial assessment and disease monitoring in IgG-variant pemphigus

Panel components include antibody testing for IgG epithelial cell surface and IgG desmoglein 1 and 3; to order individual component tests, refer to epithelial skin antibody and/or desmoglein 1 and 3 antibodies in pemphigus, IgG

To screen for pemphigus along with other possible immunobullous diseases, order concurrently with antibody panel test for pemphigoid, IgG collagen type VII antibody, AND perilesional skin biopsy for direct immunofluorescence (DIF)

Concurrent perilesional skin biopsy for DIF is important for diagnosis because of increased sensitivity (85-100% of pemphigus, pemphigoid, linear IgA disease, epidermolysis bullosa acquisita, and dermatitis herpetiformis cases are positive)

See Immunobullous Skin Diseases Testing algorithm

Clinical correlation is necessary because cell surface antibodies by IFA, usually in low titers, may be found in normal individuals (possible blood group reactivity) or in patients with fungal infections, burns, drug reactions, and other dermatoses, including other immunobullous diseases

Because of clinical overlap among immunobullous diseases and similar names, pemphigoid testing may be confused with pemphigus testing and inadvertently misordered

Testing for IgG pemphigus antibody types (most common) may be confused with IgA pemphigus testing (rare disorder)

Use pemphigus panel to monitor pemphigus disease activity; use relevant tests to monitor other immunobullous disease activity

Repeat pemphigus panel for indeterminate results and/or continuing clinical consideration of immunobullous disease

Pemphigoid Antibody Panel - Epithelial Basement Membrane Zone Antibodies, IgG and IgA, BP180 and BP230 Antibodies, IgG 0092001
Method: Enzyme-Linked Immunosorbent Assay/Indirect Fluorescent Antibody

Preferred antibody panel for initial diagnostic assessment and disease monitoring in pemphigoid, epidermolysis bullosa acquisita, and linear IgA bullous dermatosis

Panel components include IgG and IgA epithelial BMZ antibodies and IgG bullous pemphigoid BP180 & 230 antigens

To order individual component tests, refer to antibody testing for IgG BMZ, IgA BMZ, and/or IgG bullous pemphigoid BP180 & 230 antigens

To screen for pemphigoid along with other possible immunobullous diseases, order concurrently with the pemphigus antibody panel  IgG collagen type VII antibody, AND perilesional skin biopsy for direct immunofluorescence

Concurrent perilesional skin biopsy for DIF is important for diagnosis because of increased sensitivity (85-100% of pemphigus, pemphigoid, linear IgA disease, epidermolysis bullosa acquisita, and dermatitis herpetiformis cases are positive)

See Immunobullous Skin Diseases Testing algorithm

Clinical correlation is necessary because the incidence of false positives, although rare, increases with age

Because of similar names and clinical overlap among immunobullous diseases, pemphigoid testing may be confused with pemphigus testing and inadvertently misordered

Use pemphigoid panel to monitor pemphigoid disease activity; use relevant tests to monitor other immunobullous disease activity

Repeat pemphigoid panel for indeterminate results and/or continuing clinical consideration of immunobullous disease

Epithelial Skin Antibody 0090299
Method: Indirect Immunofluorescence
(Indirect Fluorescent Antibody)

General screen for immunobullous diseases

Test includes IgG and IgA BMZ antibodies (pemphigoid, epidermolysis bullosa acquisita, linear IgA disease) and IgG and IgA cell surface antibodies (IgG and IgA pemphigus subtypes)

Consider ordering concurrently with IgG bullous pemphigoid (BP180 & 230) antigens for suspected pemphigoid and/or IgG desmoglein 1 and 3 antibodies for suspected pemphigus

For more sensitive and specific testing for pemphigoid or pemphigus, refer to antibody panels for pemphigus or pemphigoid

See Immunobullous Skin Diseases Testing algorithm

Does not include testing for antibodies to target pemphigus antigens desmoglein 1 and 3, which may be more sensitive diagnostic markers in some cases (levels correlate with disease activity)

Although helpful in screening for immunobullous disease, test is not as sensitive as combination of pemphigus and pemphigoid panels

Use epithelial skin antibody test or both pemphigoid and pemphigus panels to follow patients with changing clinical features because antibody profiles may change over time

Pemphigus Antibody IgA 0092106
Method: Indirect Fluorescent Antibody

Assess and monitor patient with possible IgA pemphigus, a RARE disease with certain clinical and histopathological subtypes

If other types of pemphigus are of diagnostic consideration, order the panel test for pemphigus antibodies first or concurrently with this test

See Immunobullous Skin Diseases Testing algorithm

IgA pemphigus is a rare form of pemphigus; testing for IgG autoantibody types with pemphigus panel concurrently or before ordering this test is recommended

Clinical correlation is necessary; cell surface antibodies, usually in low titers, may also be found in normal individuals because of blood group reactivity

Use pemphigus IgA antibodies test to monitor disease activity in IgA pemphigus

Use pemphigus panel or IgG desmoglein 1 and desmoglein 3 to monitor pemphigus vulgaris and pemphigus foliaceus disease activity and response to therapy

Repeat pemphigus IgA antibodies test for indeterminate results and/or continuing clinical consideration of the disease

Desmoglein 1 and Desmoglein 3 Antibodies in Pemphigus, IgG 0090649
Method: Enzyme-Linked Immunosorbent Assay

Monitor disease in patient previously diagnosed with pemphigus and increased IgG desmoglein 1 and/or 3 antibodies; antibody levels correlate with disease activity; consider ordering with IgG epithelial cell surface antibody

If used to screen for pemphigus, this test has decreased sensitivity and specificity when compared to the pemphigus antibody panel

For initial diagnosis and monitoring disease, the antibody panel testing for pemphigus is preferred; panel components include IgG antibody testing for epithelial cell surface and IgG desmoglein 1 and 3

For diagnosing rare types of pemphigus, refer to IgA pemphigus antibody and paraneoplastic pemphigus

Concurrent perilesional skin biopsy for DIF is helpful with diagnosis because doing so increases sensitivity (>90% of pemphigus cases are positive), although it is not possible to reliably distinguish pemphigus subtypes based on DIF

See Immunobullous Skin Diseases Testing algorithm

Negative, positive,and borderline/indeterminate results should be correlated and confirmed with IFA, epithelial skin antibody test, or IgG epithelial cell surface antibodies test; indeterminate/borderline levels should be monitored

Patients with pemphigus may show reactivity to various cell surface antigens; therefore, negative/normal desmoglein 1 and 3 IgG antibody levels do not rule out pemphigus

These tests are components of pemphigus panel; pemphigus panel is optimal for initial diagnosis of pemphigus and for monitoring response to therapy; otherwise, concurrent testing is recommended with one of the following

  • IgG epithelial cell surface antibodies test
  • Epithelial skin antibody test

Correlations with IFA (epithelial skin antibody test), DIF findings, and clinical presentation are important for initial diagnosis

May not be positive in paraneoplastic pemphigus; typically not positive in IgA pemphigus, although cross expression of antibody classes may develop

Use IgG desmoglein 1 and 3 IgG antibody tests  to follow disease activity in pemphigus vulgaris and pemphigus foliaceus; use relevant tests to monitor other immunobullous disease activity

Patients with pemphigus may show antibody reactivity that changes over time; therefore, testing by both IFA for cell surface antibodies and desmoglein 1 and desmoglein 3 ELISAs with the pemphigus panel is strongly recommended periodically to follow disease activity

Tissue Transglutaminase (tTG) Antibody, IgA with Reflex to Endomysial Antibody, IgA by IFA 0050734
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody

Use along with pemphigoid and pemphigus panel tests and epidermal transglutaminase antibody, IgA, or use with epithelial skin antibody and epidermal transglutaminase antibody, IgA testing to initially diagnose and discriminate among the immunobullous skin diseases in patients suspected or known to have any type of immunobullous disease

Reflex pattern – if tTG IgA is 20 units or greater, then EMA IgA by IFA testing will be added; all EMA IgA by IFA testing is titered to endpoint

Does not detect IgG or IgA cell surface antibodies that characterize pemphigus immunobullous diseases

 
Epithelial Cell Surface Antibody IgG 0090266
Method: Indirect Fluorescent Antibody

Monitor patient with pemphigus who has positive IgG cell surface antibodies, but normal IgG desmoglein 1 and/or 3 antibody levels

For initial diagnosis and disease monitoring, the preferred test is the pemphigus antibody panel; panel components include IgG epithelial cell surface antibodies and IgG desmoglein 1 and 3

May use to screen for pemphigus or pemphigoid; however, this test has decreased sensitivity and specificity when compared to the panel tests for pemphigus antibodies or pemphigoid antibodies

See Immunobullous Skin Diseases Testing algorithm

Clinical correlation is necessary because cell surface antibodies by IFA, usually in low titers, may be found in normal individuals (possible blood group reactivity) or in patients with fungal infections, burns, drug reactions, and other dermatoses, including other immunobullous diseases

Use or IgG epithelial cell surface antibodies and/or IgG desmoglein 1 and desmoglein 3 antibody or pemphigus panel test to monitor pemphigus vulgaris and pemphigus foliaceus disease activity and response to therapy

Repeat IgG epithelial cell surface antibodies and/or IgG desmoglein 1 and desmoglein 3 antibody or pemphigus panel tests for indeterminate results and/or continuing clinical consideration of pemphigus vulgaris or pemphigus foliaceus