From the Guidelines
Bullae are large, fluid-filled blisters that form when the outer layer of skin separates from the layers beneath or when layers within the skin separate from each other, typically larger than 0.5 cm in diameter and containing clear fluid. These lesions can result from various conditions, including autoimmune disorders like pemphigus or bullous pemphigoid, as noted in the European Dermatology Forum consensus 1. According to this consensus, bullous pemphigoid is the most common autoimmune subepidermal blistering disease of the skin and mucous membranes, often presenting with itch and localized or generalized bullous lesions. The British Association of Dermatologists' guidelines also highlight the importance of differential diagnosis in autoimmune bullous diseases, including the use of DIF and salt-split IIF to distinguish between conditions like bullous pemphigoid, linear IgA disease, MMP, and EBA 1.
Causes and Characteristics
- Bullae can be caused by autoimmune disorders, severe allergic reactions, burns, friction injuries, or certain infections.
- They may appear as tense or flaccid bubbles on the skin surface and can be painful or itchy.
- The formation of bullae occurs when fluid accumulates in spaces created by the separation of skin layers, often due to antibodies attacking the structures that hold skin layers together or from direct damage to the skin.
Importance of Medical Attention
If you develop unexplained bullae, it's crucial to seek medical attention as some blistering conditions can be serious and may indicate an underlying systemic disease, as emphasized by the potential association of bullous pemphigoid with neurological disorders 1. Treatment depends on the underlying cause and may include topical or oral steroids, immunosuppressants, antibiotics for infected bullae, or simply protecting the area until healing occurs. Given the significance of morbidity and impact on quality of life associated with bullous pemphigoid, prompt and appropriate management is essential 1.
From the Research
Definition of Bullae
- Bullae refer to a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes 2
- The term "bullae" is often used to describe the formation of blisters in various skin conditions, including pemphigus and bullous pemphigoid (BP) 2
Causes of Bullae
- Autoantibodies play critical roles in the pathogenesis of bullous skin diseases, including pemphigus and BP 2
- Abnormalities in the adhesion between keratinocytes can lead to acantholysis and formation of intra-epidermal blisters, as seen in pemphigus 2
- Deficient adhesion of keratinocytes to the basement membrane can give rise to subepidermal blisters, as seen in BP 2
Types of Bullae
- Pemphigus is a type of bullous skin disease characterized by intra-epidermal blisters 2, 3
- Bullous pemphigoid (BP) is a type of bullous skin disease characterized by subepidermal blisters 2
- Staphylococcal scalded skin syndrome (SSSS) and bullous impetigo are infections caused by Staphylococcus aureus that can result in bullae 4, 5