skin vesicle
Meaning of skin vesicle: Size is what separates this from a bulla, and depth is what decides whether it heals with a scar or without one.
Definition of skin vesicle
A skin vesicle is a small blister, a raised pocket of clear fluid sitting within or just beneath the outer layer of skin. The fluid gathers where cells separate from one another or from the layer below, and it may be clear, cloudy or bloodstained. A larger pocket of the same kind is called a bulla rather than a vesicle.
How does the fluid collect?
Skin cells are joined to one another by protein rivets and anchored to the layer beneath in a similar way. When those connections fail, a space opens and tissue fluid seeps into it. Friction pulls the layers apart mechanically. Heat and chemicals kill cells so the connections give way. In some conditions the immune system attacks the connecting proteins directly. In viral infections the virus destroys cells from within, leaving a cavity behind. The result looks much the same in each case, which is why the pattern matters more than the appearance of any one lesion.
What does the depth indicate?
| Level of separation | Appearance | Healing |
|---|---|---|
| Within the outer layer | Fragile roof that breaks easily, often leaving raw skin | Usually without a scar |
| Between outer layer and dermis | Tense and firm, stays intact longer | Usually without a scar |
| Within the dermis | Deep, often painful or bloodstained | May scar |
A blister left intact keeps a sterile cover over the raw surface underneath, which is why an unbroken roof is generally left in place.
What causes them?
Friction and burns are the everyday causes, along with severe sunburn and frostbite. Viral infections produce characteristic patterns: chickenpox scatters lesions across the body in crops of different ages, while shingles and cold sores cluster within the territory of one nerve. Contact with an irritating plant or chemical leaves vesicles in streaks where the substance touched skin. Autoimmune blistering diseases, reactions to medicines, and inherited conditions in which skin is fragile from birth make up the less common causes.
Why does the pattern matter more than the lesion?
A single vesicle looks similar whatever produced it. What identifies the cause is where the lesions sit, how they are grouped, whether they arrived together or in waves, and what else is happening at the same time. Blisters confined to one band on one side of the body point somewhere very different from blisters scattered across both arms. Involvement of the mouth, eyes or genitals raises concern considerably, since that pattern accompanies the most serious blistering conditions.
Also known as
Used in a sentence
Grouped vesicles on a red base were confined to a single dermatome.
Good to know
The cause of blistering is judged from the distribution and grouping of the lesions rather than from the look of any single vesicle, and involvement of the mouth or eyes accompanies the most serious blistering conditions.
Word origin
Where “skin vesicle” comes from
From the Latin vesicula, meaning a small bladder or blister, a diminutive of vesica, meaning bladder.