What Causes It?
Blocked sebaceous (oil) glands
Damage to hair follicles
Skin trauma or injury
Swelling of hair follicles (folliculitis)
Genetic conditions such as Gardner’s syndrome
Hormonal changes affecting oil production
Chronic skin conditions like acne
Post-surgical scarring
Signs & Symptoms
Small, round, firm lump under the skin
Usually painless, slow-growing mass
Visible white or yellowish keratin material inside (if ruptured)
Redness and tenderness if infected
Warmth and swelling over the cyst area (infection)
Discharge of foul-smelling, cheesy material if ruptured