Infection

Infection occurs when microorganisms such as bacteria, fungi, or viruses invade the scalp or hair follicles, causing inflammation and damage to the skin and hair. Common signs include redness, swelling, itching, pain, pustules or crusting, flaking or scaling, and sometimes localized hair loss; infections can range from mild folliculitis to more extensive fungal infections such as tinea capitis.

Diagnosis is usually made by clinical examination and may be confirmed with swabs, cultures, or microscopic tests to identify the responsible organism, and treatment is directed at that cause with topical or oral antibiotics, antifungals, or antivirals as appropriate, along with wound care and measures to limit spread. Seek medical attention for worsening symptoms, fever, rapidly spreading redness, severe pain, or persistent hair shedding, because timely treatment reduces complications and the risk of scarring and permanent hair loss.