Bullous Pemphigoid

Bullous pemphigoid (BP) is a condition that affects the skin with an autoimmune etiology. It is often seen in those over the age of 80 and the prevalence is even higher in elderly people with neurological comorbidities such as stroke, Parkinson disease and dementia.

It is generally prevalent in people after the fifth decade of life and may occur in younger adults. However, it is rare in infants and children. There is no predisposition towards either sex or associations with HLA to indicate a genetic risk factor.

Clinical signs and symptoms

The first symptom is often intense itchiness. The skin may develop large areas that are raised before the onset of tense fluid-filled blisters called bullae. These blisters are usually surrounded by areas of either visually normal or inflamed, red skin. Eventually, the blisters burst and leave behind a mark that will crust over. Oral blisters are rare. Instead, blisters tend to arise more in the flexures of joints like inside the elbows or behind the knees.

Pathophysiology

The pathogenesis of Bullous pemphigoid is characterized by the action of autoantibodies directed at target antigens responsible for either cell-to-cell adhesion within the epidermis (skin's outermost layer) or adhesion of squamous epithelium to the dermis (the layer next to the epidermis).

The mechanism that leads to the autoimmune process is still not known. We do know that when it occurs in bullous pemphigoid, primarily IgG autoantibodies are directed towards the basement membrane zone. More specifically, they target the residential bullous pemphigoid antigens BP180, or less frequently BP230. These are components of the hemidesmosome adhesion complex at the basement membrane, which ensures the epidermal cell layer is secured to the dermis to form a waterproof seal.

The autoimmune action in bullous pemphigoid affects the basement membrane zone between the epidermis and dermis. The autoantibodies that bind to the target antigens may lead to a series of immunological reactions, which eventually lead to the destruction of the hemidesmosomes. Ultimately, the skin layers begin to separate and fluid accumulates between them to cause the formation of subepidermal blisters.

Diagnosis and treatment

The diagnosis of BP is often through clinical examination followed by confirmation through a biopsy of the affected tissue. Pathological evaluation of the biopsy can reveal inflammation of the affected skin. Further testing of the biopsy specimen can be used to reveal the location of the autoantibodies in the basement membrane layer or mucosal membrane.

Treatment aims to make the disease tolerable by decreasing the rate at which bullae form. As the majority of those affected are elderly, treatment can become more complicated, because these patients often present with other comorbidities. This makes them more susceptible to the side-effects from systemic agents.

Therapy can vary depending on the severity of the presenting case. Mild or non-extensive cases may benefit from twice daily application of potent topical steroids. In support of this, there has been research suggesting that large quantities of high-potency topical corticosteroids applied to the affected surface are safer than oral corticosteroids in controlling localized bullous pemphigoid. On the other hand, moderate to severe cases require systemic steroids. Oral prednisolone is the predominant established treatment used for rapid, definite remission.

References:

Further Reading

Last Updated: Feb 26, 2019

Afsaneh Khetrapal

Written by

Afsaneh Khetrapal

Afsaneh graduated from Warwick University with a First class honours degree in Biomedical science. During her time here her love for neuroscience and scientific journalism only grew and have now steered her into a career with the journal, Scientific Reports under Springer Nature. Of course, she isn’t always immersed in all things science and literary; her free time involves a lot of oil painting and beach-side walks too.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Khetrapal, Afsaneh. (2019, February 26). Bullous Pemphigoid. News-Medical. Retrieved on September 15, 2019 from https://www.news-medical.net/health/Bullous-Pemphigoid.aspx.

  • MLA

    Khetrapal, Afsaneh. "Bullous Pemphigoid". News-Medical. 15 September 2019. <https://www.news-medical.net/health/Bullous-Pemphigoid.aspx>.

  • Chicago

    Khetrapal, Afsaneh. "Bullous Pemphigoid". News-Medical. https://www.news-medical.net/health/Bullous-Pemphigoid.aspx. (accessed September 15, 2019).

  • Harvard

    Khetrapal, Afsaneh. 2019. Bullous Pemphigoid. News-Medical, viewed 15 September 2019, https://www.news-medical.net/health/Bullous-Pemphigoid.aspx.

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
Post a new comment
Post