Pemphigus is a group of severe, chronic, recurrent blistering skin diseases.

bubble_chart Etiology

The etiology of this disease remains unclear. Currently, most scholars believe it may be an autoimmune disorder, as indirect immunofluorescence tests have detected specific antibodies (also known as pemphigus antibodies) against intercellular substances of epidermal spinous cells in patients' sera, primarily IgG. The titer of pemphigus antibodies in the serum correlates with the severity of the disease. The reactive sites of pemphigus antibodies histopathologically correspond to the lesion sites of pemphigus (where acantholysis occurs). These antibodies act on the intercellular junctions of epidermal cells.

bubble_chart Pathological Changes

Intraepidermal acantholytic blister. Under electron microscopy, acantholysis can be observed as the dissociation of the central part of desmosomes, leading to the loss of intercellular binding capacity. This is also the pathological basis of Nikolsky's sign.

Acantholytic cells (Tzanck cells) can be found within the blister, with villous formation at the base of the blister and grade I inflammatory cell infiltration in the dermis.

In addition to the aforementioned changes, pemphigus vegetans also exhibits epidermal hyperplasia with pseudoepitheliomatous changes, and the formation of numerous eosinophilic microabscesses within the epidermis.

In pemphigus foliaceus and pemphigus erythematosus, acantholytic blisters occur in the superficial layers of the epidermis (subcorneal or within the granular layer).

bubble_chart Clinical Manifestations

This disease is also known as Sener-Usher syndrome or seborrheic pemphigus (Pemphigus seborrhoicus). It is a variant of pemphigus foliaceus, characterized mainly by erythema and small blisters, with a positive Nikolsky's sign, and may be covered with scales or crusts. It commonly occurs on the head, cheeks, chest, and back. Facial lesions often present as butterfly-shaped erythema, resembling lupus erythematosus. The head, chest, and back are frequently covered with seborrheic crusts, similar to seborrheic dermatitis.

bubble_chart Diagnosis

1. Flaccid blisters with crusts or refractory erosions on the skin.
2. Mucous membranes, especially the oral mucosa, are often the early symptoms of pemphigus vulgaris.
3. Nikolsky's sign is positive.
4. Scrapings from the base of blisters may reveal pemphigus cells (Tzanck cells).
5. Immunofluorescence examination
   1. Direct method: IgG and C3 deposits are found between epidermal cells in the lesional area. Additionally, approximately 25-30% of patients may show IgA and IgM deposits. In non-lesional areas, about 60% exhibit IgG and C3 deposits.
   2. Indirect method: Approximately 100% of patients' sera contain pemphigus antibodies. The antibody titer generally correlates with disease activity.
   In addition to the above findings, pemphigus erythematosus also shows positive antinuclear antibodies and IgG and C3 deposits at the dermo-epidermal junction, similar to findings in lupus erythematosus.

bubble_chart Treatment Measures

1. Corticosteroids: Prednisolone or Prednisone is primarily used at 40-60mg/day. Alternatively, hydrocortisone 300mg can be administered intravenously depending on the condition. After the condition is controlled, the dosage should be reduced gradually and systematically until a maintenance dose of 10-15mg/day of Prednisolone or Prednisone is reached.
2. Immunosuppressants: Cyclophosphamide 100mg/day (approximately 2mg per kg) is the main choice. The dosage should be gradually reduced to zero once the condition stabilizes. Alternatively, Azathioprine 50mg twice daily can be used.
3. Gold Therapy: For cases that are difficult to treat with conventional methods, especially persistent mucosal erosions, this therapy can serve as a supplementary treatment. Gold thioglucose is primarily used, administered via intramuscular injection once a week or every other day, with gradual dose increases.

   Week 1→4: 10mg per dose. Week 5→8: 25mg per dose. Week 9→12: 50mg per dose. After Week 13: 50mg per dose. The total cumulative dose can reach up to 1000mg.

4. Plasmapheresis: The goal of this therapy is to remove abnormal plasma components, particularly antibodies, immune complexes, and other harmful non-diffusible substances, and replace them with fresh plasma from healthy donors, fresh frozen plasma, or albumin preparations. This method serves as a supplementary therapy for patients experiencing side effects from corticosteroids. 1000ml/day for 3 consecutive days constitutes one course, with one course per week for a total of 3 courses.
5. Traditional Chinese Medicine Treatment:
   1. Excessive Toxic Heat Type: The treatment principle focuses on clearing heat and removing toxins, cooling blood, and clearing the nutrient aspect. The prescription includes charred Unprocessed Rehmannia Root, charred Lonicera Flower, Lotus Plumule, Lalang Grass Rhizome, Mongolian Snakegourd Root, Viola, Gardenia, Chinese Manyleaf Paris Rhizome, raw Liquorice Root, Coptis Rhizome, raw Gypsum. For persistent high fever, add Rhinoceros Horn 0.5g; for dry stool, add Rhubarb Rhizoma.
   2. Heart Fire and Spleen Dampness Type: The treatment principle focuses on clearing the heart and reducing fire. The prescription includes Poria, White Atractylodes Rhizome, Atractylodes Rhizome, Scutellaria, Unprocessed Rehmannia Root, Alisma, raw Liquorice Root, Forsythia, Mirabilite, Rush Pith, Bamboo Leaf, Submature Bitter Orange. For high fever, add Turtle Shell and raw Gypsum; for intense heart fire, add Lotus Plumule and Coptis Rhizome; for oral mucosal erosions, add Trollius and Genista; for dry stool, add Rhubarb Rhizoma.
   3. Qi and Yin Deficiency Type: The treatment principle focuses on tonifying qi, nourishing yin, and clearing residual toxins. The prescription includes American Ginseng, Southern Glehnia, Dendrobium, Black Scrophularia Root, Finger Citron, raw Astragalus, dried Unprocessed Rehmannia Root, Salvia, Lonicera Flower, Dandelion, Ophiopogon, and Polygala.
6. Supportive therapy and anti-infection treatment should be intensified as needed based on the condition.
7. Local Therapy: Exposure is preferred. Anti-infection topical membrane agents or 2% Gentian Violet solution can be used. For oral mucosal lesions, medications containing surface anesthetics and antibiotics, such as 1% Dyclonine or 1% Neomycin solution for gargling, can be applied.