A pustule is a bulging patch of skin that's full of a yellowish fluid called pus. It's basically a big pimple. Several conditions, ranging from something as common as acne to the once-deadly disease smallpox, can cause pustules.
When pus builds up under your skin or in a pore, it can cause a pustule.
What Causes Them?
Several conditions can lead to pustules:
- Acne: This very common skin condition causes pustules that are bigger than typical pimples. They happen when one of the pores in your skin gets so irritated that its walls break.
- Psoriasis: This is a skin condition that causes red, itchy, scaly patches on your skin. An infection, stress, certain chemicals, and some medications can all trigger an attack of pustular psoriasis.
- Rosacea: This skin condition normally makes the skin on your face red and causes pimples. But a form of the disease known as inflammatory rosacea can create pustules.
- Chickenpox: This childhood disease and other illnesses caused by a related virus cause skin lesions that become pustules as the disease progresses.
- IgA pemphigus: Pustules are also a symptom of this rare disease that makes your immune system turn on itself.
- Smallpox: Pustules were one of the most obvious signs of this deadly disease that killed millions of people in past centuries. Thanks to a vaccine, it isn't a danger anymore, but samples of the virus are locked up in laboratories in the United States and Russia.
Your doctor will treat the condition that's causing the pustules, but a topical medication you put directly on your skin or an over-the-counter treatment like calamine lotion or benzoyl peroxide gel might help with them in the meantime.