What the Smell of Your Pimples Can Tell You About Your Skin Health

Our bodies are capable of creating a lot of odd odors: from bad breath to gross gas, stinky sweat, and even strange-smelling sneezes. Now, you can add foul-smelling pimple pus to the list. Yep, pimples — when popped — can produce unpleasant scents.

If you've ever encountered a pungent pustule, you probably wondered what caused the smell and whether it was normal.

We spoke to Stacy Chimento, MD, a board-certified, Miami-based dermatologist at Riverchase Dermatology, to learn about what various types of pimple pus smells could say about your skin's health.

First, Why Do Pimples Smell?

Acne is an inflammatory skin disorder that happens when oil glands become clogged with excess oil and dead skin cells, trapping bacteria in the pores, Dr. Chimento says. This process produces an inflammatory response, which results in the development of pimples that contain pus.

When you squeeze a zit and release the pus (mixed with bacteria, blood, and debris), it can, at times, emit a foul or strange smell. This odor is simply the byproduct of the bacteria feeding on skin oil, Chimento says.

While an occasional stinky spot isn't uncommon or cause for alarm, some scents — like the three listed below — can signal more serious skin issues if they occur frequently.

Smells Like: A Foul Odor (But May Look Like Cheese)

A foul-smelling secretion with a yellowish, cottage-cheese appearance is probably related to an epidermoid cyst, a noncancerous bump beneath the skin.

“The skin is made up of a thin layer of cells that the body sheds,” Chimento says. “An epidermoid cyst forms when these cells move deeper in the skin and multiply rather than slough off.” Epidermoid cysts may also develop because of an injury or irritation, she adds.

Sometimes, this liquid drains from the cyst, and you'll catch a whiff of potent odor.

Smells Like: A Rotten Egg

The first sign of acne conglobata is multiple inflamed nodules that are filled with pus and may have a foul odor like rotten eggs, Chimento says.

To treat this type of severe acne, you must see a dermatologist, Chimento says. Your doctor may prescribe retinoids, steroids, or antibiotics to help manage the symptoms.

Smells Like: Onion or Garlic

If your blemish emanates an aroma like garlic or onions, you can blame bacteria.

Zits are filled with pus, which is essentially dead white blood cells that provide a feast for infesting bacteria, Chimento says. These bacteria are mostly anaerobic (meaning they don't require oxygen to survive), and they generate their own sulfur compounds as they grow, she explains.

That's why when you pop a zit infected with this type of anaerobic bacteria, you may notice a smell of garlic or onions, whose signature pungent scent (and flavor) comes from the presence of sulfur-containing compounds.

Though not uncommon, if this garlic or onion smell persists from your pores, you might benefit from a trip to the dermatologist to discuss prescription-strength acne treatments.

The Takeaway

• Pus that emerges when you pop a pimple can have an unpleasant odor, similar to rotten eggs or onions.
• The cause of foul-smelling pus varies. Epidermoid cysts and a rare, serious form of acne called acne conglobata, often produce pus with unpleasant odors.
• If you often have stinky pimple pus, see your dermatologist, who can perform a proper assessment and help figure out a solution.