What is Pemphigoid

TL;DR: Pemphigoid is a group of rare, chronic autoimmune blistering diseases where the body’s immune system mistakenly attacks the protective layers of the skin or mucous membranes. This process causes the skin to separate, leading to the formation of fluid-filled blisters that can affect the skin, mouth, eyes, nose, and genitals.

What exactly is Pemphigoid?

Pemphigoid is an umbrella term for a family of autoimmune disorders characterized by subepidermal blistering. Unlike some other blistering diseases, Pemphigoid occurs because the immune system produces autoantibodies that target the "basement membrane zone"—the structural glue that holds the top layer of skin (epidermis) to the underlying layer (dermis). When this connection is compromised, fluid collects between the layers, resulting in tense, firm blisters that do not rupture as easily as those seen in conditions like pemphigus vulgaris.

Which body systems are affected by Pemphigoid?

The primary system affected by Pemphigoid is the integumentary system (the skin). However, depending on the specific subtype, the disease can also involve mucosal surfaces. Common areas of involvement include:

• Skin: Large, tense blisters, often on the lower abdomen, inner thighs, or armpits.


• Oral Cavity: Painful erosions or blisters inside the mouth, which can make eating or speaking difficult.


• Ocular (Eyes): Mucous membrane pemphigoid can cause scarring of the conjunctiva, which, if untreated, may threaten vision.


• Respiratory and Genital tracts: Less commonly, these areas may develop erosions or scarring.

What are the main subtypes of Pemphigoid?

Clinical classification is important because the prognosis and treatment vary significantly between types. The most common forms include:

1. Bullous Pemphigoid: The most frequent form, typically presenting with widespread itchy blisters in older adults.


2. Mucous Membrane Pemphigoid (Cicatricial Pemphigoid): A subtype that primarily affects moist linings and carries a higher risk of scarring.


3. Pemphigoid Gestationis: A rare, pregnancy-associated autoimmune blistering disease that usually resolves after delivery.

Who is typically affected by Pemphigoid?

Pemphigoid is primarily a condition of aging. Bullous pemphigoid, for instance, most commonly affects individuals over the age of 60, with an incidence rate estimated between 6 and 43 cases per million people per year, depending on the geographic region. While it can occur in younger adults and children, it is exceptionally rare in those populations. There is no significant gender predisposition for the most common forms, and it does not appear to be linked to specific ethnic or geographic factors.

How does Pemphigoid differ from other blistering diseases?

It is vital to distinguish Pemphigoid from Pemphigus. In Pemphigus, the skin cells themselves detach from one another (acantholysis) because the antibodies attack the "cement" between cells, leading to fragile, flaccid blisters. In contrast, Pemphigoid involves the separation of the entire epidermis from the dermis, resulting in much tougher, more durable blisters. Diagnosis is typically confirmed via skin biopsy and direct immunofluorescence testing, which identifies the specific antibodies present at the basement membrane.

Currently, 95 people with Pemphigoid have joined the DiseaseMaps community, sharing their personal journeys and experiences with diagnosis and management.

Next steps

• Consult a board-certified dermatologist or an immunodermatologist experienced in autoimmune blistering diseases.


• Request a biopsy for direct immunofluorescence (DIF) to ensure an accurate diagnosis.


• Join the DiseaseMaps community to connect with others who have Pemphigoid and share your experiences.


• Keep a symptom journal to track flare-ups and potential triggers to discuss with your clinical team.

Medical disclaimer: This content is for educational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• Orphanet: Rare Disease Database


• NIH Genetic and Rare Diseases Information Center (GARD)


• Online Mendelian Inheritance in Man (OMIM)


• International Pemphigus & Pemphigoid Foundation