What is the Difference Between Pemphigus Vulgaris and Pemphigus Foliaceus?

Pemphigus vulgaris and pemphigus foliaceus are both autoimmune blistering diseases that affect the skin and mucous membranes, but they have distinct differences in their clinical presentation, histopathology, and immunopathogenesis. Here are the key differences between the two:

1. Mucosal involvement: Pemphigus vulgaris classically presents with mucosal lesions, while pemphigus foliaceus does not involve mucosal lesions and only involves skin involvement.
2. Clinical presentation: Pemphigus vulgaris usually presents with widespread mucocutaneous blisters and erosions, while pemphigus foliaceus tends to develop in a seborrheic distribution, affecting the scalp, face, and trunk. The skin lesions in pemphigus foliaceus consist of small, scattered superficial blisters that rapidly evolve into scaly, crusted erosions.
3. Histopathology: In the early stages of pemphigus foliaceus, histopathology may not be diagnostic, as the stratum corneum is often lost from the surface, and the deeper epidermis remains intact. In contrast, pemphigus vulgaris typically shows a clear pattern of acantholysis (separation of keratinocytes).
4. Immunopathogenesis: Pemphigus foliaceus is caused by immunoglobulin G (IgG) antibodies directed against desmoglein-1 (Dsg1) found in the granular layer of the epidermis. In pemphigus vulgaris, testing reveals antibodies against both Dsg3 and Dsg1.
5. Susceptibility: Susceptibility to pemphigus foliaceus has been correlated with the presence of HLA-DR4, DR-14, and DR-1, but unlike pemphigus vulgaris, no single allele has been associated with the disease.
6. Epidemiology: Pemphigus foliaceus is less common worldwide than pemphigus vulgaris, but it is more commonly encountered in some regions like New Zealand. The mean age of onset for pemphigus foliaceus is usually between 40 to 60 years.
7. Treatment: Pemphigus foliaceus can require a shorter duration of therapy compared to pemphigus vulgaris due to its milder course and different antibody targets.

Comparative Table: Pemphigus Vulgaris vs Pemphigus Foliaceus

Pemphigus vulgaris and pemphigus foliaceus are two types of autoimmune blistering diseases that affect the skin and mucous membranes. They can be differentiated by various factors, including clinical presentation, histopathology, and antibodies. Here is a table summarizing the differences between the two conditions:

In terms of treatment, pemphigus foliaceus can require a shorter duration of therapy compared to pemphigus vulgaris. The diagnosis of both conditions can be further determined by using ELISA to detect the target antigen (Dsg3 for pemphigus vulgaris and Dsg1 for pemphigus foliaceus), which is highly sensitive and specific.