Britannica Sources used in this answer

Why can skin inflammation cause blisters to form?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

skin rash caused by Lyme disease — skin disease Visible alterations in the texture of the skin, such as rashes and hives, can be indicative of serious disease. For example, one of the first signs of Lyme disease is a circular rash in a bull's-eye pattern on the skin.

Blisters form during intense skin inflammation due to the breakdown of proteins that maintain the skin's structural integrity. This degradation is triggered by enzymes released from inflammatory cells, resident skin cells, or blood plasma components.1

As these enzymes break down the structural connections, a separation occurs either between layers of the epidermis or between the epidermis and the dermis. This resulting gap fills with fluid, creating a rounded elevation on the skin. While blisters are often associated with physical friction, they also frequently appear as symptoms of contact dermatitis, viral infection, or autoimmune disease. In some conditions, such as pemphigus, the development of these fluid-filled lesions is the primary morphological feature of the disease.21