Bullous pemphigoid: symptoms, causes and treatment
Bullous pemphigoid is a very rare epidermal pathology, autoimmune in nature. It is estimated that its incidence is 2.8 patients per 10,000 inhabitants in the United States, almost always aged around 60 years. This pathology causes a variety of events on the skin, among which the appearance of blisters stands out.
In general, it is considered benign, but an annual mortality of between 23 and 28% of the people who suffer it is reported. This could be explained by the age of the patients and their fragile state of health, rather than by the disease itself. Are you interested in knowing more about it?
What is bullous pemphigoid?
Bullous pemphigoid (PA) It is the result of a dysfunction in the patient's immune system. In particular, patients present autoantibodies at the dermoepidermal junction, a structure that separates the dermis from the epidermis.
Biopsies of the lesions show type G immunoglobulins and C3 complement components in practically all cases. Some accessory immunoglobulins, such as IgM, IgA, IgE or IgD, can also be seen in the blisters. In any case, as we have said, IgG is the most prevalent, in almost 90% of cases.
The presence of these antibodies in the lesions shows that the immune system is erroneously attacking the patient's tissues. In this case, the action is directed against the fibers that connect the dermis and epidermis, which gives rise to localized inflammation and previously described lesions.
Thus, the pathogenesis of AP can be classified into 2 different categories, an immune response and an inflammatory response. Both are derived from the action of cells that protect us against viral and bacterial infections.
Antibodies bind to antigens BP180 and BP230, essential proteins in cell binding.
Causes of bullous pemphigus
According to the MSD Manual, the cause of bullous pemphigoid is still unknown. In any case, we present some factors that can favor its appearance.
1. Consumption of certain medications
Drugs such as furosemide, spirolactone, penicillin, antipsychotics, and others can promote bullous pemphigoid. According to a post on DermNet NZ, the most common drugs that trigger it are checkpoint inhibitors targeting PD-1, essential in immunotherapeutic treatments to treat melanomas.
2. Physical factors
Physical trauma to the skin, radiation therapy for the treatment of cancerous tumors and phototherapy with ultraviolet light they can promote a bullous pemphigus.
3. Predisposing disorders
Here is a list that relates certain personal diseases and conditions to bullous pemphigoid. Among them, we find the following:
- This pathology occurs in both sexes equally, so it is not linked to specific hormonal issues in men or women, as is the case with other disorders.
- There is a certain genetic predisposition in the development of the disease.
- It is more prevalent in elderly patients with neurological problems, such as those who have had a stroke or those with dementia.
- In some people it is associated with malignant neoplastic processes, that is, some types of cancer.
You must bear in mind that this pathology arises from errors in the autoimmune system, so any factor that can "confuse" it will lead to its appearance. Thus, multiple pathologies are associated with bullous pemphigoid, but none is considered a trigger in 100% of the cases.
In any case, the typical patient is one of geriatric age, 60 years of age or older. This condition is very rare in adults and children, but isolated cases have been reported in all age groups.
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Symptoms of bullous pemphigoid
The Spanish Academy of Dermatology and Venereology (AEDV) expertly shows the clinical picture of the disease. First, a series of eczema-like lesions typical of urticaria appear —Which cause a lot of itching—, on which large blisters appear that do not explode easily.
Most of the time, itching is the symptom that appears first, since the blisters do not have to become effective until several years after the disorder. As the immune system creates antibodies to damage the dermoepidermal junction, the blisters become more noticeable, painful, and reddened.
As usual, these blisters appear in the folds of the skin, especially in areas where repeated bending movements occur. Because of this, it is rare for patients to develop bullous lesions on the head and neck.
The Cleveland Clinic stresses that the first step in diagnosing bullous pemphigoid is a physical exam. The medical professional will go to the anamnesis, that is, ask the patient for certain relevant information, such as the following:
- When the symptoms appeared.
- What are your feelings.
- Family background.
After suspecting the clinical picture, a blood test and samples are taken from an affected area – biopsy. This can show the presence of antibodies that attack the body's tissues, confirming the immune disorder.
Treatment of bullous pemphigoid
According to information from the United States National Library of Medicine, corticosteroids are often the first line of treatment for PA. These relieve skin inflammation, heat, and pain. What's more, They contribute to the suppression of misdirected immune responses in the body.
The most widely used corticosteroid is prednisone, a synthetic drug that is generally taken orally, but can also be injected intramuscularly. It is often used to treat flu, asthma, fever, and cough, as it acts as an immunosuppressant on most of the person's immune system.
Frequently, prednisone treatment is systemic and prescribed as an oral pill —60 to 80 milligrams — once a day. In more localized variants of the disease, clobetasol can be used, a topical cream that reduces symptoms and avoids the consumption of many general drugs.
If corticosteroids don't work, other stronger immunosuppressive drugs are used.
The percentage of death in patients with untreated bullous pemphigoid is 18% annually. In any case, this is related to the age and health of the patients who present it. In the best cases, the pemphigoid disappears after a few months or years, even without the need for treatment.
Most affected people who respond to corticosteroid treatment achieve remission of symptoms within 2 to 10 months. Still, oral administration of drugs may be required for several years to prevent the immune system from getting out of control again and causing the aforementioned epidermal damage.
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What should you remember?
We are facing a clinical entity that is difficult to approach and understand, since, as with many other autoimmune disorders, finding a specific cause is a complex task. Certain predisposing factors have been identified, but none of them appear to be the clear and universal trigger for bullous pemphigoid.
In addition to the difficulty in finding the cause, it should be noted that treatment does not work in all patients. This can greatly worsen the prognosis of the disease, especially considering that most of those affected already have an advanced age and a delicate health condition.
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