blisters
Last reviewed 03/2021
A blister is an important physical sign in dermatology. Blisters can be divided by size into:
- vesicles which are less than 0.5 cm in diameter
- bullae which are greater than 0.5 cm in diameter
Blisters can also be divided according to the level of the histological split into:
- intra-epidermal blisters
- sub-epidermal blisters
Intra and sub-epidermal blisters can often be differentiated clinically since intra-epidermal blisters are thin roofed and easily ruptured.