Pemphigus

Indications for Testing

Presence of chronic bullae (blistering), erosive or crusting/scaling skin, and/or mucous membrane disease
Other more common diseases ruled out

Laboratory Testing

Perilesional skin biopsy by direct immunofluorescence (DIF)
- Immunohistology
  - Perilesional skin biopsy – cutaneous DIF submitted in Michel’s (or Zeus) medium
    - Pemphigus vulgaris, vegetans, and foliaceus
      - IgG and C3 (3rd 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 whereas it 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 3 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 because of overlap in clinical immunobullous disease presentations
- Pemphigus types with IgG cell surface antibodies are more common than IgA pemphigus – recommend ruling out IgG pemphigus first before testing for IgA pemphigus
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 sera
    - Presence of IgG cell surface antibodies and desmoglein antibodies in serum correlates with disease activity in the most common types of pemphigus, namely pemphigus vulgaris and pemphigus foliaceus
  - Useful to establish 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; however, desmoglein antibodies may or may not be positive
  - Refer to Paraneoplastic Pemphigus topic
Serum IgG desmoglein 1 and IgG desmoglein 3 antibody testing by ELISA
- Desmoglein 1 autoantibodies predominate in pemphigus foliaceus (and likely pemphigus erythematosus)
- Desmoglein 3 autoantibodies are present in pemphigus vulgaris (and likely pemphigus vegetans)
- Although the 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 pemphigus
- Nondesmoglein antibody pemphigus has been described; therefore, for diagnosis, IFA and IgG desmoglein 1 and IgG desmoglein 3 antibody testing advised
Serum IgA cell surface antibody testing
- Testing for IgA cell surface antibodies is important in establishing the diagnosis of IgA pemphigus, a rare variant
  - Testing is highly sensitive and specific
- Can distinguish IgA pemphigus from other pemphigus variants and from other immune-mediated skin disease
- Cell surface antibodies detected by IFA on intact human skin and monkey esophagus substrates

Differential Diagnosis

Aphthous stomatitis
Behçet disease
Candida spp
Drug reaction
Epidermolysis bullosa acquisita
Erythema multiforme
HIV acute infection
Lichen planus
Systemic lupus erythematosus
Paraneoplastic pemphigus
Pemphigoid
Stevens-Johnson syndrome
Transient acantholytic dermatosis (Grover disease)
Viral infection, herpes simplex viruses, and coxsackievirus A16 (hand-foot-and-mouth disease)

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

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

Epidemiology

Incidence - 1-2/1,000,000
Age – all ages, including childhood; usually diagnosed in 40s-50s
Sex – M:F, equal
Ethnicity
- Pemphigus vulgaris is more common in patients of 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
  - IgG desmoglein 1 antibodies predominate in pemphigus foliaceus and pemphigus erythematosus
    - Associated with nonmucosal lesions
    - Detected by enzyme linked immunosorbent assay (ELISA)
    - Levels correlate with disease activity
  - IgG desmoglein 3 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
- 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 off drug

Clinical Presentation

Flaccid blisters on face, scalp, upper body, and intertriginous areas
- Nikolsky sign – applying pressure on blister periphery extends the lesion laterally
Mucosal blisters and erosions
Types
- Pemphigus vulgaris – initial presentation is usually oral ulcers with mucosal involvement
  - Subsequent development of superficial blisters and erosions on the trunk, face, scalp, and proximal limbs
- 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 – superficial blisters typically on neck and upper trunk, "cornflake" scale as in seborrheic distribution
- 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

Treatment

Treatment, disease course, and prognosis vary with type of pemphigus identified

Tests generally appear in the order most useful for common clinical situations

Test name: Cutaneous Direct Immunofluorescence, Biopsy

ARUP #: 0092572

Methodology: Direct Immunofluorescence
(Direct Fluorescent Antibody Stain)

Use:

Use to determine the presence and characteristic staining pattern of immunoglobulins (IgG, IgM, IgA), third component (C3) of complement and fibrinogen in skin or mucous membrane biopsy specimens (biopsy site is critical; see below) from patients suspected of having pemphigus; perform this test with serum pemphigoid panel

For skin involvement, biopsy perilesional skin

For mucous membrane involvement, biopsy nonlesional mucosa

See Immunobullous Skin Diseases Testing algorithm

Limitations:

May be inaccurate if tissue not taken from correct perilesional location (attached/intact epithelium or epidermis is needed)

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

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

Follow-up:

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

See Immunobullous Skin Diseases Testing algorithm

Test name: Pemphigus Panel - IgG Epithelial Cell Surface Antibodies and Levels of IgG Desmoglein 1 and Desmoglein 3 Antibodies, Serum

ARUP #: 0090650

Methodology: Enzyme-Linked Immunosorbent Assay/Indirect Fluorescent Antibody

Use:

Panel includes epithelial cell surface IgG antibodies by IFA on intact human skin and monkey esophagus substrates, IgG desmoglein 1 and IgG desmoglein 3 antibodies by ELISAs

Use to diagnose most major types of pemphigus and to monitor disease activity and therapeutic response

Use along with pemphigoid panel and endomysial IgA antibody tests to initially diagnose and distinguish various immunobullous disorders in patients suspected or known to have any type of immunobullous disease

Concurrent perilesional skin biopsy for DIF is important for diagnosis because of increased sensitivity (85-100% of pemphigus cases are positive)

See Immunobullous Skin Diseases Testing algorithm

Limitations:

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) also may be confused with IgA pemphigus testing (rare disorder)

Follow-up:

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

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

Repeat pemphigus panel for indeterminate results and/or continuing clinical consideration of pemphigus vulgaris or pemphigus foliaceus

See Immunobullous Skin Diseases Testing algorithm

Test name: Pemphigoid Panel - Epithelial Basement Membrane Zone IgG & IgA, BP180 & BP230 IgG Antibodies

ARUP #: 0092001

Methodology: Enzyme-Linked Immunosorbent Assay/Indirect Fluorescent Antibody

Use:

Panel includes epithelial basement membrane zone (BMZ) IgG & IgA antibodies by indirect immunofluorescence (IFA) on split human skin and monkey esophagus substrates, BP180 & BP230 IgG antibodies by ELISAs

Use to diagnose most types of pemphigoid, epidermolysis bullosa acquisita, linear IgA disease (including linear IgA bullous dermatosis and chronic bullous disease of childhood), mixed immunobullous disease

Use along with pemphigus panel and endomysial 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

See Immunobullous Skin Diseases Testing algorithm

Limitations:

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

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

Test name: Epithelial Skin Antibody

ARUP #: 0090299

Methodology: Indirect Immunofluorescence
(Indirect Fluorescent Antibody)

Use:

Panel includes epithelial basement membrane zone (BMZ) IgG and IgA antibodies by IFA and IgG and IgA cell surface antibodies by IFA on split human skin, intact human skin, and monkey esophagus substrates

Use as alternate to pemphigoid and pemphigus panel tests to initially diagnose and discriminate among clinically similar immune-mediated skin diseases such as pemphigus, linear IgA disease, pemphigoid, epidermolysis bullosa acquisita, and dermatitis herpetiformis in patients suspected of having or known to have any type of subepidermal immunobullous disease

Limitations:

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

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

Follow-up:

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

Test name: Pemphigus IgA Antibodies

ARUP #: 0092106

Methodology: Indirect Fluorescent Antibody

Use:

This test comprises components included in the epithelial skin antibody test

Use to test for IgA cell surface antibodies in patients suspected of having or known to have IgA pemphigus and have tested negative for IgG pemphigus (cell surface) antibodies

Use to distinguish IgA pemphigus from other immune-mediated diseases

Use to monitor response to therapy and disease activity in IgA pemphigus

Limitations:

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

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

Follow-up:

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

See Immunobullous Skin Diseases Testing algorithm

Test name: IgG Desmoglein 1 & Desmoglein 3

ARUP #: 0090649

Methodology: Enzyme-Linked Immunosorbent Assay

Use:

These ELISA tests are components included in the pemphigus panel

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

Use to distinguish pemphigus foliaceus from pemphigus vulgaris and other immune-mediated skin disease

Use to measure relative levels of desmoglein 1 and desmoglein 3 IgG antibodies to support a diagnosis of pemphigus (may be more sensitive than IFA in some patients) and to monitor disease activity and therapeutic response

User along with epithelial cell surface antibodies by IFA for added sensitivity and to identify patients with pemphigus antibodies to epitopes other than those in the assay

Limitations:

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

Patients with pemphigus may show reactivity to various cell surface antigens; therefore, negative/normal IgG desmoglein 1 and desmoglein 3 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 and typically not positive in IgA pemphigus, although cross expression of antibody classes may develop

Follow-up:

Use IgG desmoglein 1 & desmoglein 3 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

See Immunobullous Skin Diseases Testing algorithm

Test name: Tissue Transglutaminase (tTG) Antibody, IgA with Reflex to Endomysial Antibody, IgA by IFA

ARUP #: 0050734

Methodology: Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody

Use:

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

Limitations:

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

Test name: IgG Epithelial Cell Surface Antibodies

ARUP #: 0090266

Methodology: Indirect Fluorescent Antibody

Use:

This test comprises components included in the pemphigus panel and epithelial skin antibody test

Use to test for IgG cell surface antibodies in patients suspected of having or known to have the major types of pemphigus

Use to distinguish pemphigus from other immune-mediated diseases

Use to monitor response to therapy and disease activity in pemphigus

Limitations:

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

Follow-up:

Use or IgG epithelial cell surface antibodies and/or IgG desmoglein 1 and desmoglein 3 antibody or pemphigus panel tests 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

See Immunobullous Skin Diseases Testing algorithm

General

Comprehensive Review: September 2011
Last Update: December 2012

Dermatitis Herpetiformis

Epidermolysis Bullosa Acquisita

Immunobullous Skin Diseases Screening

Linear IgA Disease

Paraneoplastic Pemphigus

Pemphigoid

Pemphigoid Gestationis

Porphyrias