Scalp Conditions: Causes, Symptoms & Treatment

What Are the Most Common Scalp Conditions?

The most common scalp conditions include dandruff (affecting ~50% of adults), seborrheic dermatitis (1-3% of population), folliculitis (hair follicle infection), scalp ringworm (fungal infection), scalp psoriasis, and various forms of hair loss. These conditions share symptoms like itching, flaking, and redness but have different underlying causes and treatments.

The scalp is a unique area of skin with a high concentration of hair follicles and sebaceous (oil) glands. This environment makes it susceptible to various conditions that can affect both the skin and hair. Understanding the differences between these conditions is crucial for effective treatment and knowing when to seek medical care.

Scalp conditions can be broadly categorized into several types based on their underlying causes. Inflammatory conditions like seborrheic dermatitis and psoriasis involve immune system dysfunction. Infectious conditions include bacterial folliculitis, fungal infections like ringworm, and parasitic infestations like head lice. Additionally, conditions like dandruff represent milder forms of inflammatory processes, while hair loss (alopecia) can result from various factors including genetics, hormones, and autoimmune conditions.

The skin of the scalp constantly renews itself, shedding dead cells in a process that is normally invisible. When this process is disrupted—whether by inflammation, infection, or other factors—visible symptoms develop. These symptoms often overlap between conditions, which is why proper diagnosis is important for effective treatment. Many scalp conditions also have a significant psychological impact, affecting self-esteem and quality of life, making effective management even more important.

Dandruff (Pityriasis Simplex Capitis)

Dandruff is the mildest and most common scalp condition, characterized by white or yellowish flakes of dead skin that fall from the scalp. Unlike more severe conditions, dandruff typically causes minimal inflammation and no visible redness. The flakes are usually small, dry, and white, distinguishing them from the larger, oilier scales of seborrheic dermatitis.

Dandruff is closely linked to a yeast called Malassezia that naturally lives on the scalp. In some individuals, an overgrowth of this yeast or an increased sensitivity to its byproducts triggers the accelerated shedding of skin cells. While dandruff is not contagious and does not cause permanent damage, it can be persistent and socially embarrassing. The condition often improves with anti-dandruff shampoos containing active ingredients like zinc pyrithione, selenium sulfide, or ketoconazole.

Seborrheic Dermatitis

Seborrheic dermatitis represents a more severe form of the same spectrum as dandruff. This condition involves significant inflammation, causing red, scaly patches covered with yellowish, greasy-looking scales. While it commonly affects the scalp, it can also appear in other oily areas of the body, including the face (around the nose, eyebrows, and ears), chest, and back.

The exact cause of seborrheic dermatitis involves a combination of factors: Malassezia yeast, sebum production, and an inflammatory immune response. The condition tends to be chronic and relapsing, meaning it may improve and then flare up again. Triggers can include stress, cold weather, hormonal changes, and certain medical conditions. Unlike simple dandruff, seborrheic dermatitis often requires prescription-strength treatments for adequate control.

Folliculitis

Folliculitis is an inflammation of the hair follicles, appearing as small red or white-headed bumps around individual hairs. On the scalp, it can cause tenderness, itching, and sometimes pain. Bacterial folliculitis is most common, typically caused by Staphylococcus aureus, but fungal causes are also possible.

Scalp folliculitis often develops after activities that damage or irritate hair follicles, such as shaving, wearing tight hats or headbands, or excessive sweating. In most cases, mild folliculitis resolves on its own within one to two weeks with good hygiene practices. However, severe or recurrent cases may require antibacterial or antifungal treatments. A particularly stubborn form called folliculitis decalvans can cause scarring and permanent hair loss if not treated promptly.

Scalp Ringworm (Tinea Capitis)

Despite its name, ringworm is not caused by a worm but by dermatophyte fungi. Scalp ringworm is highly contagious and most commonly affects children, though adults can also be infected. The condition causes round, scaly patches of hair loss, often with visible broken hairs that appear as black dots. The affected area may be itchy, and swollen lymph nodes in the neck can occur.

Scalp ringworm requires oral antifungal medication for treatment, as topical treatments cannot penetrate deep enough into the hair follicle to eliminate the infection. Early treatment is crucial to prevent spread to others and to minimize the risk of permanent scarring hair loss. The infection spreads through direct contact with infected individuals, animals (especially cats and dogs), or contaminated objects like combs, hats, and pillows.

What Are the Symptoms of Scalp Conditions?

Common symptoms of scalp conditions include itching (pruritus), visible flaking or scaling, redness and inflammation, tenderness or pain, changes in hair texture, hair loss or thinning, pustules or bumps around hair follicles, and crusting or oozing in severe cases. The specific combination and severity of symptoms help differentiate between different conditions.

Scalp conditions often share overlapping symptoms, which can make self-diagnosis challenging. However, understanding the characteristic features of each condition helps guide appropriate treatment decisions. The scalp's symptoms often reflect the underlying process—whether inflammatory, infectious, or related to abnormal skin cell turnover.

Itching is perhaps the most common and bothersome symptom across nearly all scalp conditions. The severity can range from mild, occasional itching to intense, persistent scratching that disrupts sleep and daily activities. Chronic scratching can itself cause additional problems, including secondary bacterial infection, further inflammation, and even hair loss from repeated trauma to the hair follicles.

Visual changes to the scalp provide important diagnostic clues. Dandruff produces fine, white, dry flakes, while seborrheic dermatitis causes larger, yellowish, greasy scales with underlying redness. Psoriasis creates thick, silvery-white scales on clearly defined red patches. Folliculitis appears as distinct bumps around individual hair follicles, while ringworm creates characteristic round patches with broken hairs.

Itching and Discomfort

Scalp itching, medically known as scalp pruritus, varies significantly in intensity depending on the underlying condition. Dandruff typically causes mild, intermittent itching that is more annoying than distressing. Seborrheic dermatitis produces more persistent itching, often worse during flare-ups. Folliculitis may cause localized tenderness rather than widespread itching. Head lice cause intense itching, particularly at the back of the scalp and behind the ears, due to an allergic reaction to lice saliva.

Some scalp conditions cause discomfort beyond simple itching. Scalp psoriasis can create a tight, burning sensation. Folliculitis and boils (furuncles) cause localized pain and tenderness. Inflammatory conditions may create a sensation of scalp tightness or sensitivity that makes even gentle brushing uncomfortable.

Visual Changes

The appearance of scalp symptoms provides crucial diagnostic information. Color changes range from subtle redness in mild inflammation to deep erythema (redness) in severe dermatitis or infection. Scaling varies from fine, powdery flakes in dandruff to thick, adherent plaques in psoriasis. The distribution of symptoms also matters—seborrheic dermatitis often follows the hairline and affects the areas behind the ears, while psoriasis may appear in more random patches.

In infectious conditions, additional visual signs may be present. Folliculitis shows distinct pustules or papules around hair follicles. Ringworm creates circular patches with a clearing center and raised, scaly edges. Severe bacterial infections may produce oozing, crusting, and matted hair. These visual clues, combined with symptom history, help healthcare providers make accurate diagnoses.

What Causes Scalp and Hair Follicle Problems?

Scalp conditions arise from multiple causes including fungal overgrowth (Malassezia yeast in dandruff/seborrheic dermatitis), bacterial infection (Staphylococcus in folliculitis), fungal infection (dermatophytes in ringworm), autoimmune processes (psoriasis), parasitic infestation (head lice), genetics, hormonal changes, and environmental factors like stress and climate.

The scalp's unique environment—with abundant hair follicles, sebaceous glands, and a warm, moist surface—creates conditions favorable for various microorganisms. While many of these organisms normally coexist harmlessly with the skin, disruptions in the delicate balance can trigger disease. Understanding these underlying mechanisms is essential for effective prevention and treatment strategies.

The scalp's sebaceous glands produce sebum, an oily substance that helps keep skin moisturized and protected. However, this oil-rich environment also provides an ideal habitat for Malassezia yeast, which feeds on lipids in sebum. In individuals with dandruff or seborrheic dermatitis, either an overgrowth of this yeast or an abnormal inflammatory response to it triggers the characteristic symptoms. This explains why these conditions often worsen during times of increased sebum production, such as puberty or periods of hormonal change.

Bacterial and fungal infections of the scalp typically occur when microorganisms breach the skin's natural barrier. This can happen through minor trauma, such as scratching, shaving, or wearing tight headwear. Pre-existing skin conditions that disrupt the barrier function, like eczema or psoriasis, also increase infection risk. Additionally, compromised immune function—whether from illness, medications, or systemic conditions like diabetes—makes individuals more susceptible to scalp infections.

Microbial Causes

The yeast Malassezia (formerly called Pityrosporum) plays a central role in dandruff and seborrheic dermatitis. This lipophilic (fat-loving) yeast is part of the normal skin flora but can cause problems when it overgrows or when the skin reacts abnormally to its metabolic byproducts. Malassezia breaks down sebum into oleic acid, which causes irritation and accelerated skin cell turnover in susceptible individuals. This is why anti-dandruff treatments often contain antifungal agents targeting this yeast.

Staphylococcus aureus bacteria commonly cause bacterial folliculitis. These bacteria are present on healthy skin but can cause infection when they enter hair follicles through breaks in the skin. Methicillin-resistant S. aureus (MRSA) is becoming an increasingly important cause of recurrent or treatment-resistant folliculitis. Other bacteria, including Pseudomonas aeruginosa (associated with hot tub folliculitis), can also cause scalp infections.

Dermatophyte fungi cause ringworm (tinea capitis). The most common species affecting the scalp vary by geographic region but include Trichophyton tonsurans (predominant in North America and Europe) and Microsporum canis (often transmitted from pets). These fungi invade the hair shaft itself, causing it to weaken and break, which produces the characteristic "black dot" appearance of broken hairs at the scalp surface.

Inflammatory and Autoimmune Causes

Several scalp conditions involve abnormal immune responses. Scalp psoriasis results from an accelerated immune-mediated skin cell cycle, causing thick, silvery scales on red, inflamed patches. Approximately 50% of people with psoriasis experience scalp involvement. Unlike seborrheic dermatitis, psoriasis plaques are typically more sharply defined and may extend beyond the hairline onto the forehead and neck.

Alopecia areata is an autoimmune condition where the immune system attacks hair follicles, causing round patches of hair loss without visible scaling or inflammation. While the scalp skin appears normal, the hair loss can be distressing. Other autoimmune conditions affecting the scalp include lichen planopilaris and lupus erythematosus, both of which can cause scarring hair loss if not treated promptly.

Environmental and Lifestyle Factors

Various environmental factors influence scalp health. Cold, dry weather can worsen dandruff and seborrheic dermatitis by disrupting the skin barrier. Conversely, hot, humid conditions promote sweating and may trigger folliculitis. Sun exposure, while sometimes beneficial for psoriasis, can damage the scalp skin and hair.

Lifestyle factors also play a role. Stress is a well-documented trigger for seborrheic dermatitis flares and may worsen psoriasis and trigger alopecia areata. Poor nutrition, particularly deficiencies in zinc, B vitamins, and essential fatty acids, can affect scalp health. Hair care practices—including harsh shampoos, chemical treatments, tight hairstyles, and excessive heat styling—can damage the scalp and contribute to various conditions.

When Should You See a Doctor for Scalp Problems?

Seek medical care for scalp problems if symptoms persist beyond 2-3 weeks despite over-the-counter treatment, if you notice spreading redness or signs of infection, if hair loss accompanies your symptoms, if you develop fever or swollen lymph nodes, or if symptoms significantly impact your quality of life. Seek urgent care for rapidly spreading infection, severe pain, or signs of systemic illness.

Many scalp conditions can be effectively managed at home with over-the-counter products. However, certain signs indicate that professional evaluation is necessary. Recognizing these warning signs ensures timely treatment of conditions that could worsen without proper medical intervention, particularly those that might cause permanent hair loss or spread to others.

The persistence of symptoms despite appropriate home treatment is a key indicator that medical evaluation is needed. If you have used an anti-dandruff or antifungal shampoo correctly for 2-3 weeks without improvement, the diagnosis may be wrong or a stronger treatment may be required. Similarly, symptoms that initially improve but then worsen or frequently recur warrant professional assessment to identify underlying factors and develop a more effective management plan.

Certain symptom patterns require prompt medical attention. Any rapid spread of redness, swelling, or pustules suggests active infection that may need prescription treatment. Hair loss occurring alongside scalp symptoms is concerning because it may indicate a condition capable of causing permanent damage to hair follicles. Systemic symptoms like fever, malaise, or painful swollen lymph nodes suggest that a scalp infection may be spreading and requires more aggressive treatment.

Red Flags Requiring Urgent Evaluation

Certain presentations require same-day medical evaluation. A rapidly expanding area of redness and swelling, especially with accompanying warmth and tenderness, may indicate cellulitis—a bacterial infection of the deeper skin layers that can spread quickly and become serious. Any scalp abscess (a painful, fluctuant swelling filled with pus) needs professional drainage and likely antibiotic treatment.

In children, suspected scalp ringworm should be evaluated promptly because of its highly contagious nature and the potential for spread in school or childcare settings. A severe inflammatory reaction to ringworm called a kerion—appearing as a boggy, swollen, pus-draining mass—requires immediate treatment to minimize the risk of permanent scarring and hair loss.

How Are Scalp Conditions Treated?

Treatment depends on the specific condition. Dandruff and mild seborrheic dermatitis respond to medicated shampoos containing zinc pyrithione, selenium sulfide, ketoconazole, or coal tar. Folliculitis often resolves with good hygiene; severe cases need antibiotics. Scalp ringworm requires oral antifungal medication. Scalp psoriasis is treated with topical corticosteroids, vitamin D analogs, or phototherapy. Treatment duration varies from weeks to ongoing maintenance therapy.

Effective treatment of scalp conditions begins with accurate diagnosis, as different conditions require different therapeutic approaches. While many conditions can be managed with over-the-counter products, others require prescription medications. The treatment approach typically starts with the least aggressive options and escalates if needed. Understanding the available treatments helps patients make informed decisions and set realistic expectations for results.

Most scalp conditions are chronic or recurrent, meaning ongoing management rather than a one-time cure is the goal. This is particularly true for dandruff, seborrheic dermatitis, and psoriasis. Successful long-term management often involves identifying and avoiding triggers, establishing a consistent treatment routine, and being prepared to intensify treatment during flare-ups. Patient education about the nature of their condition and realistic expectations is a crucial part of effective management.

The choice of treatment also considers factors like patient preference, cost, convenience, and potential side effects. For example, some patients prefer leave-on treatments while others prefer rinse-off shampoos. Some treatments require daily use initially but can be reduced to maintenance frequency once symptoms are controlled. Working with a healthcare provider to find the most effective and practical regimen increases the likelihood of long-term success.

Medicated Shampoos

Over-the-counter medicated shampoos are the first-line treatment for dandruff and mild seborrheic dermatitis. Each active ingredient works through a different mechanism, and some individuals respond better to certain ingredients than others. If one type of medicated shampoo is not effective after 4-6 weeks of consistent use, trying a different active ingredient is recommended.

Zinc pyrithione has antibacterial and antifungal properties and is gentle enough for daily use. Selenium sulfide (1% over-the-counter, 2.5% prescription) reduces Malassezia and slows skin cell turnover. Ketoconazole (1% OTC, 2% prescription) is a powerful antifungal that directly targets the Malassezia yeast implicated in dandruff and seborrheic dermatitis. Coal tar slows skin cell turnover and reduces itching and scaling, making it particularly useful for scalp psoriasis. Salicylic acid helps soften and remove scales, often used in combination with other treatments.

Proper use of medicated shampoos significantly affects their effectiveness. The shampoo should be worked into the scalp (not just the hair) and left on for 3-5 minutes before rinsing to allow adequate contact time with the active ingredient. Initially, daily or every-other-day use may be needed; once symptoms improve, frequency can typically be reduced to once or twice weekly for maintenance.

Prescription Treatments

When over-the-counter treatments are insufficient, prescription options include stronger versions of the same medications and additional therapeutic classes. Prescription-strength ketoconazole 2% shampoo or other antifungal shampoos like ciclopirox may be prescribed for resistant seborrheic dermatitis. Topical corticosteroids in solution, foam, or oil formulations reduce inflammation and are often used for short-term control of flares.

For scalp psoriasis, topical vitamin D analogs (calcipotriene) can be used alone or in combination with corticosteroids. More severe cases may require phototherapy (UV light treatment) or systemic medications including oral retinoids, methotrexate, or newer biologic agents that target specific parts of the immune system.

Folliculitis treatment depends on severity and cause. Mild bacterial folliculitis may respond to antibacterial washes containing chlorhexidine or benzoyl peroxide. More severe or persistent cases require oral antibiotics selected based on likely bacterial cause and local resistance patterns. Fungal folliculitis (pityrosporum folliculitis) requires antifungal treatment, either topical for mild cases or oral for more extensive involvement.

Treatment for Specific Conditions

Scalp ringworm (tinea capitis) requires oral antifungal medication because topical treatments cannot reach the infection within the hair follicle. Griseofulvin was traditionally the standard treatment, but newer options like terbinafine, itraconazole, and fluconazole may be preferred due to shorter treatment courses and better tolerability. Treatment typically continues for 4-8 weeks. Adjunctive use of antifungal shampoo can reduce spore shedding and help prevent spread to others.

Head lice are treated with pediculicides (lice-killing products). Over-the-counter options include permethrin 1% (first-line treatment) and pyrethrin-based products. Prescription options for resistant lice include malathion, benzyl alcohol, spinosad, and ivermectin (topical or oral). Successful treatment also requires meticulous combing to remove nits (lice eggs) and treating close contacts simultaneously to prevent reinfestation.

How Can You Prevent Scalp Problems?

Prevention strategies include regular shampooing to control oil buildup, avoiding harsh hair products and excessive heat styling, not sharing personal items like combs and hats, managing stress, eating a balanced diet, protecting the scalp from sun damage, treating underlying skin conditions promptly, and avoiding tight hairstyles that traumatize hair follicles.

While not all scalp conditions can be prevented, many can be minimized through good scalp hygiene and care practices. Establishing healthy habits reduces the risk of developing problems and helps manage existing conditions more effectively. Prevention is particularly important for conditions like folliculitis that often result from controllable factors.

Basic scalp hygiene forms the foundation of prevention. Regular washing removes excess sebum, dead skin cells, and environmental debris that can contribute to problems. The optimal washing frequency varies by individual—those with oily scalps may need daily washing, while those with dry scalps may do better with less frequent washing. Using a gentle, pH-balanced shampoo appropriate for your hair type helps maintain a healthy scalp environment without stripping away protective oils.

The products we use on our hair and scalp significantly impact scalp health. Heavy styling products can clog hair follicles and contribute to folliculitis. Harsh ingredients can irritate the scalp and disrupt its natural barrier function. Chemical treatments like coloring, perming, or relaxing can damage the scalp if done too frequently or applied incorrectly. Choosing products suited to your hair type and allowing adequate time between chemical treatments helps protect scalp health.

Daily Care Practices

Consistent daily practices help maintain optimal scalp health. Brush or comb hair gently to distribute natural oils and remove loose flakes without traumatizing the scalp. Massage the scalp during washing to improve circulation and help dislodge debris. Rinse thoroughly to remove all product residue, which can otherwise build up and cause irritation. Allow hair to air dry when possible, as excessive heat from blow dryers can dry out the scalp.

Protect your scalp from environmental damage. Wear a hat in strong sunlight, as sunburn can damage the scalp and may trigger certain conditions. In cold, dry weather, moisturizing treatments can help prevent excessive dryness. If you swim regularly, rinse hair with fresh water before and after swimming to minimize exposure to chlorine or salt water, which can be drying and irritating.

Preventing Infection Spread

Certain scalp infections, particularly ringworm and head lice, spread easily from person to person. Never share personal items that contact the scalp, including combs, brushes, hats, helmets, pillows, and towels. If someone in your household has a contagious scalp condition, check all family members and clean shared items appropriately. Ringworm on combs and brushes can be killed by soaking in a bleach solution; lice cannot survive more than 24-48 hours off the human host.

For folliculitis prevention, keep the scalp clean and dry, especially after sweating. Avoid tight hats or headbands that trap sweat and create friction. If you shave your scalp, use a clean, sharp razor and shave in the direction of hair growth to minimize follicle trauma. Consider using an aftershave product with antibacterial properties.

What Causes Hair Loss with Scalp Conditions?

Scalp conditions can cause hair loss through several mechanisms: inflammation disrupting the hair growth cycle (telogen effluvium), direct damage to hair follicles from infection (ringworm), scarring destruction of follicles from severe inflammation (cicatricial alopecia), and habitual scratching causing traction. Most hair loss from scalp conditions is reversible with treatment, but scarring conditions cause permanent loss.

Hair loss accompanying scalp conditions is a common concern that causes significant distress. Understanding whether hair loss is likely to be temporary or permanent helps patients and healthcare providers make appropriate treatment decisions. In most cases, treating the underlying scalp condition leads to hair regrowth, but some conditions can cause irreversible damage if not addressed promptly.

The hair follicle is a dynamic structure that cycles through phases of growth (anagen), transition (catagen), and rest (telogen). Various scalp conditions can disrupt this cycle, pushing more hairs into the resting and shedding phases than normal. This type of hair loss, called telogen effluvium, is typically diffuse (affecting the whole scalp) and reversible once the triggering condition is controlled. Seborrheic dermatitis and scalp psoriasis can cause this pattern of hair loss during flares.

Infectious conditions may cause hair loss through direct damage to the hair or follicle. Scalp ringworm invades the hair shaft, causing it to become brittle and break at the surface. This creates the characteristic "black dot" appearance of broken hairs. With appropriate antifungal treatment, the hair typically regrows normally. However, if severe inflammation (kerion) occurs, scarring can result in permanent hair loss in the affected area.

Scarring vs. Non-Scarring Hair Loss

The distinction between scarring (cicatricial) and non-scarring alopecia is crucial. Non-scarring hair loss leaves the hair follicles intact, meaning hair can regrow once the underlying cause is addressed. Conditions causing non-scarring hair loss include most cases of seborrheic dermatitis, mild folliculitis, and treated ringworm.

Scarring alopecia destroys the hair follicles themselves, making hair loss permanent in the affected areas. Conditions that can cause scarring include severe bacterial infections, fungal infections with kerion formation, folliculitis decalvans, lichen planopilaris, and discoid lupus erythematosus. Early recognition and treatment of these conditions is essential to minimize permanent damage. Warning signs of scarring alopecia include smooth, shiny areas of hair loss without visible follicle openings, and hair that does not regrow despite treatment of the underlying condition.

Pattern Hair Loss vs. Scalp Condition-Related Hair Loss

It's important to distinguish hair loss caused by scalp conditions from androgenetic alopecia (pattern hair loss), which is genetic and hormonal rather than related to scalp disease. Pattern hair loss affects 50% of men by age 50 and a significant proportion of women, appearing as receding hairline and crown thinning in men or diffuse thinning in women.

Pattern hair loss can coexist with scalp conditions, and sometimes treating an underlying scalp condition reveals pattern hair loss that was previously masked. If hair loss continues despite successful treatment of a scalp condition, evaluation for other causes of hair loss, including pattern hair loss, thyroid disorders, or nutritional deficiencies, may be warranted.

Are Scalp Conditions Different in Children?

Children are particularly susceptible to scalp ringworm (tinea capitis) and head lice, which spread easily in schools and daycare settings. Cradle cap (infant seborrheic dermatitis) is common in babies and usually resolves spontaneously. Children are less likely than adults to develop dandruff but can develop other scalp conditions. Treatment approaches may differ due to age-related medication considerations.

Scalp conditions in children present unique considerations, both in terms of which conditions are most common and how they are treated. The developing immune system, close contact with other children in school and daycare settings, and differences in scalp physiology all influence the epidemiology of pediatric scalp conditions.

Infants commonly develop cradle cap (seborrheic dermatitis of infancy), appearing as thick, yellow, greasy scales on the scalp. This condition is thought to result from residual maternal hormones stimulating sebaceous glands. While the appearance can be alarming to parents, cradle cap is harmless and typically resolves spontaneously by 6-12 months of age. Gentle cleansing and application of mineral oil to soften scales before brushing can help manage the appearance. Severe cases may benefit from mild medicated shampoo formulated for infants.

School-age children are the group most affected by scalp ringworm (tinea capitis), which spreads easily through close contact and shared items. In many countries, scalp ringworm causes epidemic outbreaks in schools. The condition requires oral antifungal treatment, as topical medications cannot penetrate adequately. Griseofulvin has traditionally been the first-line treatment in children, though terbinafine and other newer antifungals may be used depending on the specific fungal species involved.

Head Lice in Children

Head lice infestation (pediculosis capitis) is extremely common among school-age children, affecting millions worldwide each year. Contrary to popular belief, head lice are not related to poor hygiene—they actually prefer clean hair. Lice spread through direct head-to-head contact, which is common during children's play and activities.

Symptoms include intense scalp itching (though some children are asymptomatic), visible nits (eggs) attached to hair shafts near the scalp, and occasionally visible live lice. Treatment involves pediculicide products (permethrin or pyrethrin-based) applied according to package directions, meticulous combing with a fine-toothed nit comb, and treating household contacts simultaneously. Treatment typically needs to be repeated after 7-10 days to kill lice that have hatched from surviving nits.

Prevention of head lice spread involves teaching children not to share combs, brushes, hats, or hair accessories. Schools no longer recommend routine screening or "no-nit" policies, as these have not been shown to reduce transmission and can cause unnecessary stigma. Children with head lice can usually continue attending school after beginning treatment.