Dermatology - Pemphigoid

Dr. Corey Simpson

What are the protective layers of the skin and mucosae?

Blade > Epidermis > Dermis > Fat

What is the composition of the epidermis

Cornified > Granular > Spinous > Basal > Basement Membrane

What is the differential diagnosis for oral erosions?

1. Pemphigus Vulgaris (PV)

2. Mucous Membrane Pemphigoid (MMP)

3. Oral Lichen Planus (OLP)

4. Erythema Multiforme (EM)

What is the pathophysiology of pempigus vulgaris

Autoantibodies against desmosomes (Dsg1, Dsg3) → loss of adhesion between keratinocytes (acantholysis)

What is the pathophysiology of phemphigoid?

Autoantibodies against hemidesmosomes (BP230, BP180, Laminin 332) → separation at the basement membrane

What is the pathophysiology of lichen planus?

Lichenoid inflammation → destruction of basal keratinocytes via immune attack

What is the pathophysiology of erythema multiforme?

Dead keratinocytes separate from BM due to immune response to HSV, drugs, or other triggers

What is the patient presentation of pemphigus?

Oral erosions, painful blisters, skin involvement, weight loss in severe cases

What is the patient presentation of pemphigoid

Oral, ocular, genital, nasal erosions

What is the patient presentation of lichen planus?

Reticular white striae (Wickham’s striae), erosive ulcers, pain

What is the patient presentation of erythema multiforme?

target lesions on palms, oral ulcers, systemic symptoms

What is the histology or immuno-fluorescense pattern of PV?

DIF: Intercellular IgG & C3 between keratinocytes

What is the histology or immuno-fluorescense pattern of MMP?

DIF: IgG, C3 at basement membrane

What is the histology or immuno-fluorescense pattern of LP?

DIF: Linear fibrin deposits at basement membrane

What is the histology or immuno-fluorescense pattern of EM?

DIF: Non-specific inflammation with necrotic keratinocytes

What are some special notes about PV?

Needs systemic immunosuppression, Rituximab is FDA-approved

What are some special notes about MMP?

Ocular referral is necessary to prevent scarring/blindness

What are some special notes about LP?

Can be associated with Hep C, screen before immunosuppressants

What are some special notes about EM?

Associated with HSV, supportive treatment

why should you test for hep B before immunosuppressants?

risk of reactivation with immunosuppressants like rituximab

why should you test for hep C before immunosuppressants?

associated with LP

Why is maintaining oral hygiene difficult in oral erosive diseases?

Due to pain and sensitivity, making brushing and flossing uncomfortable

What are recommended oral hygiene practices for patients with oral erosions?

Use a soft toothbrush, alcohol-free mouthwash, and chlorhexidine (short-term to avoid staining)

what is the first-line topical treatment for oral erosions?

Topical steroids, such as dexamethasone rinse or clobetasol gel

What are possible side effects of topical steroids?

Risk of oral candidiasis (thrush), tissue thinning, and delayed healing

When are systemic steroids used?

For moderate to severe cases when topical steroids are not enough.