A boil is a red, swollen, painful bump under the skin. It often starts in an infected hair follicle. Bacteria form an abscess or pocket of pus. Boils can occur anywhere. They are most common on the face, neck, armpits, buttocks, groin, and thighs.
There are several types:
Furuncle or carbuncle—come from staph infections, may occur in a group
Pilonidal cyst—forms in the crease of the buttocks
Cystic acne—occurs when oil ducts become clogged and infected
Acne. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/acne . Accessed January 29, 2021.
Boils. DermNet New Zealand website. Available at: https://www.dermnetnz.org/topics/boils. Accessed January 29, 2021.
Hidradenitis suppurativa. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hidradenitis-suppurativa . Accessed January 29, 2021.
Nodulocystic acne. DermNet New Zealand website. Available at: https://www.dermnetnz.org/topics/nodulocystic-acne. Accessed January 29, 2021.
Nowicka D, Grywalska E. Staphylococcus aureus and host immunity in recurrent furunculosis. Dermatology. 2019;235(4):295-305.
Pilonidal disease. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/pilonidal-disease. Accessed January 29, 2021.
Skin abscesses, furuncles, and carbuncles. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/skin-abscesses-furuncles-and-carbuncles . Accessed January 29, 2021.
Last reviewed September 2020 by
EBSCO Medical Review Board
Shawna Grubb, RN
Last Updated: 2/24/2021
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