Acne is a very common skin condition. It affects many people across ages, genders, and regions.

There are many different types of acne, too. Knowing your specific type of acne will help you choose the right treatment.

Acne develops when a skin pore (hair follicle) becomes clogged with oil and skin cells. Bacteria feed on this excess oil and multiply. At this stage, the clogged pore can develop into one of two categories of acne:

Read on to learn why papules form and how to stop them in their tracks.

A papule is a small red bump. Its diameter is usually less than 5 millimeters (about 1/5 of an inch).

Papules don’t have a yellow or white center of pus. When a papule does accumulate pus, it becomes a pustule.

Most papules become pustules. This process commonly takes a few days.

While tempting, it’s recommended to not pop pustules. Doing so can risk bacteria spreading further as well as scarring.

If you must pop a pustle, follow these steps. You can also try an acne patch.

When excess oil and skin cells clog a skin pore, the blockage is known as a comedo. The oil in this clogged pore feeds bacteria that live on your skin called Propionibacterium acnes (P. acnes).

A microcomedone is formed during this process. You can often see and feel the microcomedone. It can develop into a larger structure called a comedone.

If the comedone ruptures and disperses the bacteria into the skin tissue — as opposed to on the skin’s surface — your body will respond with inflammation to fight the bacteria. This inflamed lesion is a papule.

The primary causes of papules, and acne in general, include:

  • bacteria
  • excess oil production
  • excess activity of androgens (male sex hormones)

Acne can also be triggered or aggravated by:

Your doctor may recommend starting with nonprescription acne treatments, like benzoyl peroxide or salicylic acid. If these aren’t effective after a few weeks, your doctor may refer you to a dermatologist who can prescribe stronger medications.

For inflammatory acne, your dermatologist may prescribe topical dapsone (Aczone). Other topical recommendations might include:

  • Retinoid (and retinoid-like) drugs. Retinoids include adapalene (Differin), tretinoin (Retin-A), and tazarotene (Tazorac).
  • Antibiotics. Topical antibiotics can kill excess bacteria on the skin and reduce redness. They’re typically used with other treatments, such as erythromycin with benzoyl peroxide (Benzamycin) or clindamycin with benzoyl peroxide (BenzaClin). Sometimes antibiotics are used with retinoids.

Based on the severity of your acne, your dermatologist might recommend oral medications, such as:

If you have a papule that’s large and seems to be especially swollen and painful, it might not actually be a papule. It could be an acne nodule.

Nodules and papules are similar, but nodules start deeper in the skin. Nodules are more severe than papules. They commonly take more time to heal and have a higher risk of leaving a scar.

If you suspect you have nodular acne, see your dermatologist. They can help you get relief and prevent it from scarring.

A papule looks like a tiny, raised bump on the skin. It develops from excess oil and skin cells clogging a pore.

Papules have no visible pus. Typically the papule will fill with pus in a few days. Once pus is visible on the surface of the skin, it’s called a pustule.

Papules are a symptom of inflammatory acne. Over-the-counter and prescription treatments can treat papules, depending on their severity. If over-the-counter treatments aren’t working after a few weeks, see your dermatologist.