Boils and carbuncles and Symptoms

Boils and carbuncles are painful, pus-filled bumps that form under your skin when bacteria infect and inflame one or more of your hair follicles.

Boils (furuncles) usually start as red, tender lumps. The lumps quickly fill with pus, growing larger and more painful until they rupture and drain. A carbuncle is a cluster of boils that form a connected area of infection under the skin.

You can usually care for a single boil at home, but don't attempt to prick or squeeze it — that may spread the infection. Call your doctor if a boil or carbuncle is extremely painful, lasts longer than two weeks or occurs with a fever.

Symptoms

Boils
Boils can occur anywhere on your skin, but appear mainly on your face, neck, armpits, buttocks or thighs — hair-bearing areas where you're most likely to sweat or experience friction. Signs and symptoms of a boil usually include:

• A painful, red bump that starts out about the size of a pea
• Red, swollen skin around the bump
• An increase in the size of the bump over a few days as it fills with pus (can sometimes reach the size of a golf ball)
• Development of a yellow-white tip that eventually ruptures and allows the pus to drain out.

Once the boil drains, the pain usually subsides. Small boils usually heal without scarring, but a large boil may leave a scar.

Carbuncles
A carbuncle is a cluster of boils that often occurs on the back of the neck, shoulders or thighs. Carbuncles:

• Cause a deeper and more severe infection than single boils do
• Develop and heal more slowly than single boils do
• Are likely to leave a scar

Signs and symptoms that may accompany carbuncles include:

• Feeling unwell in general
• Fever
• Chills

When to see a doctor
You usually can care for a single, small boil yourself. But see your doctor if you have:

• A boil on your face or spine
• A boil that worsens rapidly or is extremely painful
• Boils that are very large, haven't healed in two weeks or are accompanied by a fever
• Frequent boils
• A condition that suppresses your immune system, such as an organ transplant, corticosteroid use or an HIV infection
• Recently been hospitalized

Children and older adults who develop one or more boils also should receive medical care.