Pemphigus vulgaris, a rare chronic vesicular skin disease that has aroused human interest since ancient Greece, is the most common member of the pemphigus family. Its name is derived from the Greek word "pemphix" which means blister. Pemphigus forms primarily because the body's own antibodies attack proteins that structure the connections between skin cells, a process that reflects an autoimmune pathology. Over time, without treatment, the blisters and ulcers that appear on the skin of patients will continue to increase, which is worrying.
The mortality rate without medical treatment was close to 90%. Today, with treatment, this figure has been reduced to between 5% and 15%, but it is still considered a potentially fatal disease.
Symptoms of pemphigus are most commonly manifested in the mouth, especially the cheeks and roof of the mouth. In addition to blisters in the mouth, blisters may also be seen on the skin surface. The disease is characterized by tender blisters that generally spare the skin of the palms and soles of the feet. These blisters often rupture and form erosive lesions, which have a significant impact on the patient's quality of life. Loss of the pleasure of eating and ongoing pain can lead to weight loss and malnutrition.
The appearance of Nikolsky's sign is an indicator sign of the disease, that is, blisters appear after slight friction on normal skin.
The pathophysiology of pemphigus is caused by antibodies directed against demyelinating proteins (desmoglein 1 and 3), which are intercellular structures in the skin. The presence of these antibodies leads to the separation of skin cells in the epidermis, forming blisters, a phenomenon called "cell detachment." Histologically, the keratinocytes of the basal layer remain connected to the basement membrane, a phenomenon known as the "tombstone appearance." As the bonds between cells are destroyed, auditory fluid accumulates between the keratinocytes of the skin, forming blisters that are easy to break away.
Due to its low prevalence, the diagnosis of pemphigus is often confusing and time-consuming. In the early stages, patients may develop mouth ulcers or skin blisters. Further diagnosis can be made through a biopsy, where the tissue taken is tested with immunofluorescence staining, which clarifies damage to the connections between cells. The standard test is to take a sample of the skin surrounding the lesion, and special techniques can see damage to the antibodies.
The gold standard for confirming the diagnosis of pemphigus is biopsy and direct immunofluorescence examination.
Historically, corticosteroids and other immunosuppressive agents have been widely used to reduce the symptoms of pemphigus. However, these drugs are associated with serious and long-term side effects, so their use should be limited as much as possible. In recent years, monoclonal antibodies such as rituximab have shown better efficacy and have become the preferred indirect treatment. With full FDA approval in 2018, many patients are experiencing remission after just one dose of rituximab.
Early interventional treatment can improve the efficacy, and rituximab combined with intravenous immunoglobulin therapy has been free of recurrence for 10 years during follow-up.
The prevalence of pemphigus in the UK is approximately 1 to 5 cases per million people, while the global incidence rate is 1 to 10 cases per million people. The number of cases in the United States is expected to exceed 14,000. In the Israeli study, the incidence of the disease was significantly higher among Jews, with the risk being one-forty that of other ethnic groups. However, without proper treatment, approximately 80% of patients will die within a year from infection or fluid loss due to ulcers.
The focus on rare diseases always seems to sound alarm bells, and researchers continue to seek more effective treatments and consider possible future gene therapy and cell therapy options. Do these studies offer hope for people with pemphigus?