Boil vs. cyst vs. carbuncles
It can be easy to confuse boils with carbuncles or cysts, but there are differences.
A carbuncle is simply a few boils grouped together. A cyst, on the other hand, is a smooth, round, closed sac under your skin filled with fluid or semisolid material.
Boils and cysts can both look like bumps on your skin. The main difference between a cyst and a boil is that a boil is a bacterial or fungal infection.
Most cysts are slow-growing and benign (noncancerous), and they aren’t contagious. Boils, on the other hand, can spread bacteria or fungi on contact.
The following table gives an overview of the differences between a boil, a cyst, and a carbuncle:
Type | Symptoms | Causes | Risk factors | Treatment |
---|---|---|---|---|
Boil | presents as a red pimple that may swell and ooze; grows rapidly and is usually painful | results from a bacterial or fungal infection | risk factors include skin conditions like acne, psoriasis, or eczema; close contact with someone who has a boil; compromised immune system; diabetes; obesity | applying a warm, moist compress; keeping a clean bandage over the boil; avoidingpicking; if symptoms don’t improve, draining the puss, cleansing the area, and treating with antibiotics may be necessary |
Carbuncle | similar to single boils but may be accompanied by fever; often occurs at the back of the neck and extends deeper into the tissue than boils | similar to boils, caused by an infection, most commonly from staph bacteria | similar risk factors to boils | similar to boils, but even more important to release the puss either with a drawing salve ointment or surgical draining followed by cleansing the wound; antibiotics may be necessary and may be administered intravenously |
Cyst | presents as a smooth nodule under the skin that’s movable, grows slowly, and usually isn’t painful unless inflamed | the cause of many cysts is unknown but may include an injury, swollen hair follicle, the human papillomavirus (HPV), or chronic ultraviolet light; some types of cysts may be hereditary, and some are associated with disorders like Gardner’s syndrome | people assigned male at birth may be more at risk since most types of cysts are more common in them than in people assigned female at birth | most cysts need no treatment, and they may disappear on their own, but they may recur; treatment can involve antibiotics or surgery to drain the cyst (usually if the cyst can move under the skin) |