Large acne pimples and boils can look very similar. They are both swollen, painful lumps with white heads. They are both filled with thick, yellowish fluid.
Acne pimples and boils are not the same, though. They have different causes and treatments. This means you need to know which one you have before you can treat it.
This article describes some of the differences between pimples and boils, and how they should be treated.
What Is a Boil?
Boils are also called furuncles or abscesses. They are infected hair follicles.
Staphylococcus aureus bacteria are the most common cause of boils. Other bacteria and fungus can also cause boils, though.
A boil looks like a large acne pimple. It starts as a painful, firm, red lump under the skin. Over the course of several days, it grows larger, softens, and develops a white, pus-filled head.
At first it can be hard to tell the difference between a boil and a pimple. A pimple can also start out as a firm, red, painful lump.
What Is a Pimple?
A pimple is not caused by an infection. It’s caused by a blocked pore. The pore becomes blocked by a plug of oil and dead skin cells.
The oil and dead skin cells irritate the pore, causing redness and swelling. The acne-causing bacteria Propionibacterium acnes also play a role.
Locations for Pimples
If the large blemish is on your face, it’s probably an acne pimple. Pimples are common on the face, upper back, shoulders, and chest area.
Severe or cystic acne can cause very large, tender, inflamed blemishes. These cyst-like blemishes are in deeper structures of the skin than typical pimples. They can look similar to boils.
You may sometimes get large, lone pimples even if you don’t have regular breakouts. These usually go away within a week or so.
Locations for Boils
A large lump that appears in these places is probably a boil:
Groin Thigh Breast Armpit Foot
You don’t usually get acne in these places. This means if you have a bump there it’s unlikely to be a pimple. Boils, though, are very common in these areas.
Still, boils are also common in the face and neck area, just like acne. So location alone isn’t always enough to determine if it’s a boil or pimple.
Size of Boils
One of the key differences between boils and pimples is size. The size of boils vary. They can be the size of a cherry and up to the size of a walnut, sometimes even larger. A blemish that size is most likely a boil.
Size of Pimples
Some pimples can grow very large. Even the largest pimple, though, won’t get much larger than a dime.
Sometimes these lumps can last a few months. This depends on how deep and inflamed the pimple was.
Ice can help relieve some of the swelling and pain. Wrap an ice cube in a soft cloth and hold it over the pimple for a couple of minutes. Do this two to three times a day. Icing won’t help the pimple heal faster, but it can help it feel better.
An over-the-counter (OTC) spot treatment containing benzoyl peroxide or Differin (adapalene) can also help.
Both these products can relieve inflammation and help the blemish heal more quickly. Note, though, that topical medications don’t work as well on very deep blemishes.
You can help your boil to come to a head. Cover it with a warm, damp compress several times a day.
Make sure you wash your hands well before and after touching your boil. Don’t ever try to lance or pop it.
Call a doctor if:
If you aren’t getting results with home careYour boil is getting worseYour boil is very painfulYou’re feeling unwell
You should also call a doctor if your boil is on your face or you have multiple or recurring boils.
Your doctor can lance and drain your boil. Prescribed medication can help clear the infection.
You may be able to tell the difference based on location. Pimples usually appear on the face, back, shoulders, and chest. Blemishes that appear elsewhere may be boils.
Pimples are rarely larger than a dime. Boils may be much larger than that.
You can treat a pimple with ice and a spot treatment like benzoyl peroxide. A boil can be treated with a warm, damp compress to help it come to a head and drain.
See a doctor if your boil doesn’t get any better or you are in pain or feel unwell.
A Word From Verywell
They can look very similar, but boils and pimples are completely different skin problems. They’re treated differently too. That’s why it’s important to know what you have before starting home care.
If you still aren’t sure what’s causing your inflamed whitehead, call your doctor. A simple exam will lead to the right diagnosis and treatment.
