Vesicle

What is it?

A vesicle is a small blister filled with clear fluid that is less than 1 centimeter in size (smaller than a pencil eraser). Think of it like a tiny water balloon on your skin - it has a thin roof and contains clear liquid. Vesicles are common in many conditions, from cold sores and chickenpox to allergic reactions and eczema. When they break, they often leave a shallow erosion that crusts over.

What does it look like?

Vesicles have characteristic features:

• Small fluid-filled blisters, pinpoint to pencil eraser size
• Contents: Clear fluid (like water), may become cloudy over time
• Shape: Usually dome-shaped or spherical
• Surface: Thin, translucent roof that may appear shiny
• Color: The fluid is clear, surrounding skin may be red
• Fragility: Break easily with minor trauma
• Patterns: May appear singly, in groups, or in lines

Where does it appear?

Vesicles commonly develop on:

• Lips and mouth area: Cold sores (herpes simplex)
• Face and trunk: Chickenpox, shingles
• Hands and feet: Dyshidrotic eczema, hand-foot-mouth disease
• Areas of contact: Allergic contact dermatitis (poison ivy)
• Along nerve paths: Shingles follows dermatomal distribution
• Anywhere: Drug reactions, viral infections

Associated features

Vesicles may be accompanied by:

• Burning or tingling before vesicles appear
• Pain, especially with herpes infections
• Intense itching (eczema, allergic reactions)
• Grouping of vesicles ("herpetiform" pattern)
• Progression to crusting as vesicles break
• Clear to cloudy fluid changes
• New vesicles appearing as others heal
• Fever with widespread vesicular eruptions

When to see a doctor

Seek medical attention for:

• Vesicles with severe pain (possible shingles)
• Vesicles around the eye area
• Widespread vesicles with fever
• Recurring vesicles in the same location
• Vesicles that look infected (pus, increasing redness)
• Vesicles in infants or elderly patients
• Vesicles after starting new medication
• Any vesicles if you have a weakened immune system