Cyst Formation

Cyst formation on the scalp refers to the development of small, usually benign sacs beneath the skin that can contain keratin, sebum, or other material. Common types include epidermal inclusion cysts and pilar (trichilemmal) cysts; they often arise from blocked hair follicles, trauma, or proliferation of epidermal cells and typically present as slow-growing, round, firm or rubbery lumps that may be mobile beneath the skin.

Many scalp cysts are asymptomatic and only noticed for cosmetic reasons, but they can become painful, inflamed, or infected and sometimes lead to localized thinning or loss of hair if they exert pressure or cause scarring. Diagnosis is usually clinical, occasionally supported by ultrasound, and management ranges from observation for small, symptom-free cysts to surgical excision of the entire cyst wall for recurrent, symptomatic, or infected lesions; antibiotics may be used for active infection, and definitive removal lowers the risk of recurrence but can leave a scar that may affect nearby hair follicles.