Chapter 192: Bullous Pemphigoid

PATIENT STORY

A native of Panama was seen for extensive bullous disease that had a classic presentation for bullous pemphigoid (BP) (Figure 192-1). The classic presentation of BP is described as tense blisters that have an erythematous or urticarial base and are often pruritic. The presence of numerous intact bullae seen in this patient made pemphigus vulgaris very unlikely, as pemphigus has flaccid bullae. The Panama patient was treated with a systemic glucocorticoid (prednisone) and responded quickly. The patient eventually had a good outcome with the oral prednisone.

INTRODUCTION

BP is a chronic autoimmune blistering disease, more commonly of older adults, that may cause significant morbidity and poor quality of life. The term pemphigoid refers to its similarity to the blisters seen in pemphigus. However, BP is usually less severe than pemphigus vulgaris and is not considered a life-threatening condition.

EPIDEMIOLOGY

• BP is the most frequent autoimmune blistering disease of the skin and mucosa.

• It typically affects persons older than 65 years of age but can occur at any age.

• There is no racial or gender predilection (a recent British population study, however, suggested an increased prevalence in women).¹

• Its incidence may be on the rise.¹

• Although it is not considered life threatening, it has been associated with an increased risk of mortality (hazard ratio [HR] 2.3, 95% confidence interval [CI] 2 to 2.7).¹

ETIOLOGY AND PATHOPHYSIOLOGY

• BP is a chronic autoimmune disorder of the skin.

• Immunoglobulin (Ig) G antibodies against BP180 antigen of the basement membrane protein are considered pathognomonic and can be found in up to 65% of patients.²

• Anti-BP230 antibodies are present in virtually all patients but are not considered pathognomonic.³

• Binding of antibodies to the basement membrane activates the complement system, leading to chemotaxis of inflammatory cells such as eosinophils and mast cells, which release proteases. The subsequent degradation of hemidesmosomal proteins leads to blister formation.

• There are several morphologically distinct clinical presentations:

  • Generalized bullous form is the most common (see Figure 192-1). Tense bullae occur on both erythematous and normal-appearing skin surfaces. The bullae usually heal without scarring.

  • Localized form of BP is less common and is limited to a small area of involvement (Figure 192-2).

  • Vesicular (also known as "eczematous") form is characterized by clusters of small tense blisters with an urticarial or erythematous base.

  • Other forms are less common and include vegetative (intertriginous vegetating plaques), urticarial (without any bullae), nodular (resembling prurigo nodularis), acral (bullae on palms, soles, and face in children associated with vaccination), and generalized erythroderma (exfoliative lesions ...