Scalp Ringworm (Tinea Capitis) and Hair Loss: What You Need to Know

What does tinea capitis look like?

The classic presentation is one or more patches of hair loss on the scalp, often with fine white or gray scaling that does not respond to dandruff shampoo. The affected area may have short, broken hairs at scalp level — called "black dots" — where the hair shafts have been weakened and snapped by the fungal infection. The scalp in the patch can look dull, scaly, or mildly inflamed.

In some people, especially those who mount a strong inflammatory response, the infection triggers intense swelling and pus — the kerion — which can be alarming and is a medical urgency requiring prompt evaluation 1Ref 1Al Aboud AM, Crane JS (2023).Tinea Capitis.'The inflammatory type may result in a kerion, a painful nodule with pus, and scarring alopecia'; kerion 'might lead to permanent hair loss' and needs prompt systemic treatment to lower the risk of permanent alopecia.. The infection is contagious and spreads through direct contact with infected scalp or hair, and through shared items such as combs, hats, and pillowcases.

Why does scalp ringworm cause hair loss?

Tinea capitis is caused by dermatophytes — fungi, typically species of Trichophyton or Microsporum — that invade the hair shaft and the follicle opening. As they grow, they weaken the structural integrity of the hair, causing it to break at or just above the scalp. The fungal invasion also triggers inflammation in the follicle.

When inflammation is mild and treated promptly, the follicle recovers and hair regrows. When inflammation is severe — as in a kerion — it can cause irreversible scarring of the follicle, leading to permanent bald patches 1Ref 1Al Aboud AM, Crane JS (2023).Tinea Capitis.'The inflammatory type may result in a kerion, a painful nodule with pus, and scarring alopecia'; kerion 'might lead to permanent hair loss' and needs prompt systemic treatment to lower the risk of permanent alopecia.. Early treatment is therefore not just about clearing the infection but about preventing permanent follicle damage.

Why oral medication is required — not just shampoo

Topical antifungal creams and shampoos can reduce surface fungal spread but cannot penetrate the hair shaft and follicle where the infection lives. Tinea capitis always requires systemic treatment with an oral antifungal — a fact established in clinical practice guidelines 2Ref 2Kakourou T, Uksal U; European Society for Pediatric Dermatology (2010).Guidelines for the management of tinea capitis in children.Systemic treatment required because topical agents cannot penetrate the hair follicle; Wood's lamp and culture for confirming clearance; adjunctive antifungal shampoo for household contacts.

A systematic Cochrane review of 25 randomized controlled trials (4,449 participants) found that griseofulvin remains effective and is the preferred agent for Microsporum species infections, while terbinafine may be more effective than griseofulvin for Trichophyton tonsurans (the predominant species in North America) at a shorter treatment duration 3Ref 3Chen X, Jiang X, Yang M, et al. (2016).Systemic antifungal therapy for tinea capitis in children.Cochrane review (25 RCTs, 4,449 participants): griseofulvin preferred for Microsporum; terbinafine more effective than griseofulvin for Trichophyton tonsurans at shorter treatment duration. The specific agent, dose, and duration are determined by the child's age and weight, the species involved, and other clinical factors.

Antifungal shampoo (ketoconazole or selenium sulfide) is sometimes used alongside oral treatment to reduce environmental shedding of infectious material, but it is adjunctive — not a replacement for oral therapy.

What to expect during and after treatment

Scalp scaling and symptoms often begin improving within a few weeks of starting oral treatment. Hair regrowth typically follows once the infection is cleared, though full regrowth can take several months after treatment ends. A clinician will likely want a follow-up to confirm the infection has resolved — sometimes a scalp culture or Wood's lamp examination (a special ultraviolet light that causes some Microsporum species to fluoresce green) is used to verify clearance 2Ref 2Kakourou T, Uksal U; European Society for Pediatric Dermatology (2010).Guidelines for the management of tinea capitis in children.Systemic treatment required because topical agents cannot penetrate the hair follicle; Wood's lamp and culture for confirming clearance; adjunctive antifungal shampoo for household contacts.

If a kerion developed and left scarring, some degree of permanent hair loss in that patch is possible. This is why seeking care promptly — especially when a kerion is forming — significantly reduces the risk of lasting loss.

Managing contagion and household spread

Tinea capitis spreads through direct contact with infected hair or scalp, and through shared objects such as combs, brushes, hats, towels, and pillowcases. Siblings and close school contacts should be evaluated. Household contacts who are asymptomatic may still carry the fungus and could reinfect the treated person; antifungal shampoo for household members is sometimes advised 2Ref 2Kakourou T, Uksal U; European Society for Pediatric Dermatology (2010).Guidelines for the management of tinea capitis in children.Systemic treatment required because topical agents cannot penetrate the hair follicle; Wood's lamp and culture for confirming clearance; adjunctive antifungal shampoo for household contacts.

Household pets — especially cats — can harbor dermatophytes without visible symptoms and serve as a reservoir for reinfection. Treatment of the pet may be advisable depending on the species identified. Do not share personal hair items during treatment, and check with your child's school about their attendance policy during active infection.