Pustule

What is it?

A pustule is a small bump on the skin filled with pus - a thick, white or yellow fluid made up of dead white blood cells, bacteria, and tissue debris. These are what most people call "pimples" or "whiteheads." While pustules often indicate infection or inflammation, not all pustules contain bacteria - some form from sterile inflammation. They're common in acne, infections, and certain inflammatory skin conditions.

What does it look like?

Pustules have recognizable features:

• Small raised bumps with visible white or yellow centers
• Size: Usually less than 1 cm (pencil eraser size)
• Color: White, yellow, or cream-colored center with red base
• Shape: Dome-shaped with a visible collection of pus
• Feel: Tender or painful to touch
• Surface: May have a thin roof that ruptures easily
• Surrounding skin: Often red and inflamed

Where does it appear?

Pustules commonly develop on:

• Face: Acne, rosacea (cheeks, forehead, chin, nose)
• Scalp: Folliculitis, scalp acne
• Back and chest: Acne, folliculitis
• Beard area: Folliculitis barbae, pseudofolliculitis
• Arms and legs: Folliculitis, insect bites
• Buttocks: Folliculitis from friction or sweating
• Anywhere hair grows: Hair follicle infections

Associated features

Pustules may be accompanied by:

• Pain or tenderness
• Itching or burning sensation
• Multiple pustules in the same area
• Other acne lesions (blackheads, papules, nodules)
• Crusting after pustules rupture
• Temporary dark spots after healing
• Fever if widespread infection
• Scarring if picked or squeezed

When to see a doctor

Seek medical attention for:

• Widespread pustules appearing suddenly
• Pustules with fever or feeling unwell
• Painful, deep pustules (may be developing into abscesses)
• Pustules that don't improve with over-the-counter treatments
• Recurring pustules in the same locations
• Pustules leaving scars or dark marks
• Pustular rash after starting new medication
• Pustules around the eyes