How do lice bites look on the head?

Understanding Lice and Their Bites

What are Head Lice?

Head lice, scientifically Pediculus humanus capitis, are wing‑less insects that live on human scalps. Adults measure 2–4 mm, have a flattened, elongated body, and are tan to grayish‑brown. Their six legs end in claw‑like tarsi that grasp hair shafts. Female lice lay oval eggs—nits—firmly attached to the base of hair strands.

The life cycle consists of three stages. Eggs hatch in 7–10 days, releasing nymphs that resemble miniature adults. Nymphs molt three times over 9–12 days before reaching maturity. An adult lives up to 30 days, during which it feeds several times daily.

Feeding involves piercing the epidermis with a needle‑like mouthpart and injecting saliva that contains anticoagulants. The immune response produces a localized red papule. Typical bite manifestations include:

Small, pinpoint red spots, often clustered.
Slight swelling or a raised bump at the site.
Intense itching that intensifies after a few hours.
Distribution mainly along the hairline, behind the ears, and on the neck.

Repeated bites can lead to excoriations, secondary infection, or hyperpigmentation. Recognizing these signs alongside the presence of live lice or nits confirms an infestation.

The Biting Mechanism of Lice

Lice attach to hair shafts near the scalp and insert a specialized mouthpart called a stylet. The stylet penetrates the epidermis to reach superficial blood vessels. Saliva, containing anticoagulants, is injected to prevent clotting and facilitate continuous blood flow. The insect then draws blood through the hollow canal of the stylet, feeding for several minutes before withdrawing.

The feeding process triggers a localized inflammatory response. The skin around the puncture site becomes erythematous, forming tiny red papules that may coalesce into larger patches with repeated bites. These lesions are often accompanied by intense itching caused by histamine release. In the early stage, the bite appears as a pinpoint dot; after 24–48 hours, it may swell slightly and develop a raised border. Repeated feeding can produce a pattern of multiple punctures, typically arranged in clusters that follow the distribution of hair.

Key characteristics of the lesions include:

Size: 1–3 mm in diameter.
Color: pink to bright red, sometimes progressing to a darker hue if scratched.
Texture: smooth surface initially, becoming raised and flaky with prolonged irritation.
Distribution: concentrated on the nape, behind the ears, and at the hairline where lice prefer to lay eggs.

Understanding the mechanism of lice feeding clarifies why bites manifest as small, itchy, red spots that may evolve into larger, irritated areas when the infestation persists.

Why Lice Bites Cause Symptoms

Lice bites appear as tiny, red, raised spots on the scalp, often clustered near the hairline, behind the ears, or at the nape of the neck. The lesions may be surrounded by a pale halo and can develop a small central puncture mark where the insect inserted its mouthparts.

The symptoms arise from the biological activity of lice saliva. When a louse feeds, it injects anticoagulant proteins and allergens into the skin. These substances trigger an immediate immune response:

Histamine release causes itching and swelling.
Local inflammation produces redness and a warm sensation.
Repeated exposure sensitizes the skin, intensifying the reaction.
Scratching can breach the epidermis, allowing bacterial entry and leading to secondary infection.

The combination of chemical irritation and the body’s defensive mechanisms explains why the bite sites are uncomfortable and why they may progress from a simple papule to a more pronounced, inflamed area.

Identifying Lice Bites on the Scalp

Common Locations of Bites

Lice bites typically appear where the insects can easily access the scalp and skin. The most frequent sites include:

The back of the neck, especially the nape region.
The base of the skull, near the occipital area.
The hairline at the forehead, where hair density is lower.
The ears, particularly the outer rim and behind the lobes.
The area behind the ears, where hair often rests against the skin.

These locations share common features: thin skin, warmth, and proximity to hair shafts, which facilitate feeding. Bites in these zones often present as small, red, raised spots that may itch or develop a halo of irritation. The pattern and concentration of lesions can help differentiate lice activity from other dermatological conditions.

Visual Characteristics of Fresh Bites

«Small, Red Bumps»

Lice bites appear as tiny, raised, red spots on the scalp. The lesions are typically 1‑3 mm in diameter and may be slightly itchy. They often cluster near the hairline, behind the ears, and at the nape of the neck, where lice commonly feed. The redness results from localized inflammation caused by the insect’s saliva.

Key characteristics:

Uniform size and shape, resembling pinpricks.
Slight swelling that fades within a few days if the infestation is treated.
Possible secondary irritation if the skin is scratched.

Differentiation from other conditions:

Unlike allergic reactions, the bumps are confined to areas where lice have access.
Unlike fungal infections, the lesions lack scaling and do not spread beyond the hair‑covered regions.
Unlike mosquito bites, lice bites are not randomly distributed across exposed skin.

Management includes:

Prompt removal of live lice with a fine‑tooth comb.
Application of a pediculicide according to label instructions.
Soothing creams or antihistamines to reduce itching and inflammation.
Washing clothing, bedding, and personal items in hot water to prevent re‑infestation.

Observation of the described red bumps, especially when accompanied by live lice or nits, confirms the typical presentation of a head‑lice bite.

«Minute Puncture Marks»

Lice feeding creates tiny, pinpoint puncture marks on the scalp. These lesions are typically 1–2 mm in diameter, appear as shallow red dots, and may develop a central dot where the mandibles entered the skin. The surrounding area often shows a faint halo of inflammation, which can become more pronounced if the host scratches.

Key visual cues:

Uniform size and shape across affected zones
Linear or clustered arrangement following hair‑shaft patterns
Red to pink coloration, sometimes with a darker central point
Absence of crust or pus in early stages

The marks usually emerge within hours after a feeding session and may persist for several days. Their appearance differs from allergic dermatitis, which presents larger, irregular plaques, and from flea bites, which tend to be larger and more widely spaced. Recognizing these minute puncture marks aids in diagnosing head‑lice infestation promptly.

Visual Characteristics of Older Bites

«Crusted Sores»

Crusted sores are thickened, scab‑covered lesions that may develop when an individual repeatedly scratches or irritates bite sites on the scalp. The lesions form a hard, yellow‑white or brown crust that adheres tightly to the skin and can be difficult to remove without causing pain.

Typical appearance of lice‑related bite lesions includes:

Small, reddish papules surrounded by a clear halo.
Intense itching leading to excoriation.
Development of a central crust as the skin heals, creating a raised, dry plaque.
Possible secondary infection, indicated by swelling, pus, or foul odor.

Distinguishing crusted sores from other scalp conditions:

Dermatophytosis: usually presents with circular, scaly patches and hair loss, not isolated crusted plaques.
Scalp psoriasis: produces silvery scales over larger areas, not confined to bite sites.
Folliculitis: shows pustules around hair follicles without the thick, dry crust characteristic of crusted sores.

Effective management involves:

Removing live lice with a fine‑toothed comb and appropriate pediculicide treatment.
Applying topical antiseptic or corticosteroid ointment to reduce inflammation and prevent infection.
Keeping the scalp clean and avoiding excessive scratching to limit crust formation.
Consulting a healthcare professional if lesions enlarge, become painful, or show signs of bacterial infection.

«Scratches and Scabs»

Lice bites on the scalp typically present as small, red punctate lesions. The skin around each puncture may become irritated, leading the person to scratch. Repeated scratching can break the surface tissue, creating thin, raised scars that harden into scabs. These scabs often appear as pale or pinkish crusts that overlay the original bite site.

Key visual cues of scratches and scabs caused by lice include:

Linear or clustered pattern of tiny red spots, each corresponding to a bite.
Adjacent areas of excoriated skin where the epidermis has been removed.
Overlying crusts that are slightly elevated, sometimes with a dry, flaky texture.
Mild swelling or a subtle halo of erythema surrounding the central puncture.

The progression from fresh bite to scab follows a predictable timeline: initial redness and itching, followed by scratching‑induced erosion, and finally formation of a thin, protective crust that resolves as the skin regenerates. Recognizing these stages helps differentiate lice‑related lesions from other scalp conditions.

Differentiating Bites from Other Skin Conditions

«Dandruff»

Lice bites appear as tiny, red punctate lesions scattered across the scalp. The spots are often surrounded by a faint halo of inflammation and are accompanied by intense itching. In many cases, the bites cluster near the hairline or behind the ears, where adult lice tend to feed.

Dandruff presents as white or yellowish flakes that detach easily from the scalp surface. The condition is characterized by a dry, scaly scalp without localized redness or raised points. It does not provoke a burning sensation and rarely leads to visible irritation.

Key distinctions:

Color: Lice bites are red; dandruff flakes are white or yellow.
Texture: Bites are solid, raised points; dandruff consists of loose, powdery particles.
Location: Bites concentrate near hair follicles; dandruff spreads uniformly across the scalp.
Symptoms: Bites cause itching and occasional swelling; dandruff causes mild itch but no swelling.
Response to treatment: Antiparasitic shampoos eliminate bites, while anti‑dandruff agents reduce flaking.

Recognizing these differences prevents misdiagnosis and ensures appropriate treatment for either infestation or scalp dermatitis.

«Psoriasis»

Psoriasis on the scalp can be mistaken for the marks left by head lice. Both conditions produce red or inflamed areas, but they differ in pattern, texture, and associated signs.

Psoriatic lesions are typically well‑defined plaques covered with silvery‑white scales. The scales adhere firmly to the skin and may extend beyond the hairline. Underlying skin often appears thickened and may bleed when scratched. Psoriasis frequently coexists with nail changes such as pitting or discoloration.

Lice bites appear as small, isolated punctate lesions. They are usually clustered near the hairline and behind the ears. The bites are raised, pink to red papules that may itch intensely. No scaling or thickening of the skin accompanies the bites, and there is no nail involvement.

Key distinguishing points:

Scale presence: thick, silvery scales → psoriasis; absent → lice bites.
Lesion size: plaque‑sized, several centimeters → psoriasis; pinpoint, a few millimeters → lice bites.
Distribution: widespread, may cover entire scalp → psoriasis; concentrated around hairline, neck, behind ears → lice bites.
Associated signs: nail pitting, oil‑rich plaques → psoriasis; intense itching, visible lice or nits → lice bites.

Accurate identification relies on visual assessment of scaling and lesion morphology. If uncertainty persists, microscopic examination of hair shafts for nits or a skin biopsy for psoriatic histology can confirm the diagnosis.

«Allergic Reactions»

Lice bites on the scalp often trigger an allergic response in sensitive individuals. The reaction typically manifests as small, red papules surrounding the bite site. In many cases, the lesions are clustered near the hairline or behind the ears, where adult lice attach to feed.

Key characteristics of an allergic reaction to lice bites include:

Erythema: localized redness that may spread outward from the bite.
Pruritus: intense itching, frequently leading to secondary excoriation.
Swelling: mild to moderate edema, sometimes forming a raised bump.
Vesiculation: occasional formation of tiny blisters in severe cases.
Dermatitis: chronic exposure can provoke a papular or eczematous rash.

The severity of these signs depends on the individual's hypersensitivity. Persons with a history of atopic dermatitis or other allergies are more likely to experience pronounced inflammation. Repeated scratching can introduce bacterial infection, indicated by pus, increased warmth, or expanding redness.

Management strategies focus on reducing the allergic component while eliminating the lice infestation:

Topical corticosteroids: reduce inflammation and itching.
Antihistamines: oral or topical agents alleviate pruritus.
Emollients: restore skin barrier after irritation.
Pediculicide treatment: eradicate lice to prevent further bites.
Hygienic measures: wash bedding and clothing in hot water, vacuum upholstery.

Monitoring the progression of symptoms is essential. Persistent or worsening lesions warrant medical evaluation to rule out secondary infection or alternative dermatological conditions.

Associated Symptoms of Lice Infestation

Intense Itching

«Why Itching Occurs»

Lice bites manifest as tiny, erythematous papules, frequently grouped near the hairline, nape, or behind the ears. Each spot often shows a pinpoint puncture at its center and may be surrounded by a faint halo of inflammation.

Itching arises when the insect injects saliva while feeding. Salivary proteins act as foreign antigens, prompting the body’s immune system to release histamine and other mediators. These chemicals stimulate peripheral nerve endings, producing the characteristic urge to scratch.

Factors that intensify the sensation include:

Individual allergic sensitivity to lice saliva
High density of bites in a localized area
Secondary bacterial infection from broken skin
Prolonged scratching, which further irritates nerve endings

The combined effect of immune activation and nerve stimulation explains why the scalp becomes intensely itchy after a lice infestation.

«Severity of Itching»

Lice bites on the scalp trigger itching that can range from barely noticeable to intense, persistent discomfort. The intensity of the sensation depends on the individual’s skin sensitivity, the number of bites, and the duration of the infestation.

Mild itching usually appears as occasional, fleeting pruritus that subsides quickly after scratching. The skin may show a few tiny red dots, each roughly 1 mm in diameter, without swelling. This level of irritation often resolves within a day or two once the lice are removed.

Moderate itching is characterized by frequent urges to scratch, lasting several hours. Red papules become more numerous, often clustered near the hairline or behind the ears. Swelling may be present, and the skin can feel warm to the touch. Scratching may lead to superficial excoriations, increasing the risk of secondary infection.

Severe itching involves constant, overwhelming urges to scratch, persisting for days. Bites form a dense rash of inflamed, raised welts that can coalesce into larger areas of redness. The scalp may become sore, and extensive scratching can cause deep skin breaks, bleeding, or crusting. Persistent inflammation may indicate an allergic reaction to lice saliva, requiring medical evaluation.

Indicators that itching severity warrants professional attention:

Rash spreading rapidly across the scalp or onto the neck and face
Development of pus, oozing, or crusted lesions
Persistent pain, swelling, or warmth beyond the bite sites
Signs of secondary infection such as fever or swollen lymph nodes
Inability to control itching with over‑the‑counter treatments

Understanding the gradations of itch intensity helps differentiate a simple lice infestation from complications that need medical intervention. Prompt removal of lice, combined with appropriate topical or oral therapies, reduces itching and prevents skin damage.

Irritation and Inflammation

Lice bites appear as small, red papules clustered near the scalp, often concentrated at the nape, behind the ears, and along the hairline. The lesions are usually 1–3 mm in diameter, with a pinpoint center that may develop a tiny puncture mark.

The bite site triggers a localized skin reaction characterized by:

Sharp itching that intensifies several hours after the bite.
Tingling or burning sensation around the papule.
Mild swelling that may merge with adjacent lesions, forming a larger erythematous area.

Inflammatory response includes:

Redness spreading outward from the central point, indicating vasodilation.
Warmth to the touch, reflecting increased blood flow.
Occasionally, a thin layer of clear fluid exudes, forming a tiny vesicle that ruptures and crusts.

Persistent scratching can exacerbate inflammation, leading to secondary infection, increased edema, and prolonged erythema. Prompt removal of lice and topical anti‑itch or anti‑inflammatory agents reduce symptom duration and prevent tissue damage.

Secondary Infections

«Bacterial Infections from Scratching»

Lice bites on the scalp produce small, red papules that often itch intensely. The urge to scratch can damage the epidermis, creating entry points for skin‑resident bacteria.

Common bacterial agents that colonize these micro‑abrasions include Staphylococcus aureus and Streptococcus pyogenes. Once introduced, they can multiply rapidly, leading to secondary infection.

Typical signs of bacterial involvement are:

Increased pain or throbbing beyond the usual itch
Swelling that spreads beyond the bite site
Pus‑filled lesions or crusted scabs
Warmth and redness extending into surrounding tissue
Fever or malaise in severe cases

Effective response consists of:

Immediate cleansing of the affected area with mild antiseptic solution.
Application of topical antibiotic ointment covering the entire scratched region.
Oral antibiotics prescribed when cellulitis or extensive infection is evident.
Avoidance of further scratching by using antihistamine creams or oral agents to reduce itch.
Regular inspection of the scalp to monitor lesion progression and ensure complete resolution.

Prompt treatment prevents deeper tissue involvement and reduces the risk of long‑term scarring.

«Swollen Lymph Nodes»

Lice bites on the scalp appear as small, red papules, often grouped near the hairline or behind the ears. The lesions may be pruritic and sometimes develop a central punctum where the insect’s mouthparts have pierced the skin. In severe infestations, numerous bites can create a mottled, erythematous area that resembles a rash.

Swollen lymph nodes are a common systemic response to the inflammation caused by repeated bites. The cervical and occipital lymph nodes, situated along the sides of the neck and behind the skull, may enlarge to 1–2 cm in diameter. Enlarged nodes feel firm, mobile, and may be tender to pressure. They typically develop within a few days of sustained irritation and persist while the infestation remains untreated.

The presence of enlarged cervical or occipital nodes helps clinicians distinguish lice‑induced dermatitis from other scalp conditions such as fungal infections or allergic contact dermatitis, which rarely produce significant lymphadenopathy. When lymph node enlargement is accompanied by fever, malaise, or rapid growth, further evaluation is warranted to exclude secondary bacterial infection or other systemic illnesses.

Effective treatment of the underlying infestation—mechanical removal of lice and nits, topical insecticides, and thorough cleaning of personal items—generally reduces both cutaneous lesions and associated lymph node swelling. If nodes remain enlarged after eradication of lice, a short course of anti‑inflammatory medication may be considered, and persistent enlargement should be investigated with imaging or biopsy as appropriate.

Sleep Disturbances

Lice bites on the scalp often cause itching, redness, and small raised spots that can intensify during the night. The irritation disrupts the normal sleep cycle, leading to difficulty falling asleep, frequent awakenings, and reduced deep‑sleep duration. Persistent scratching may result in secondary skin infections, further aggravating sleep quality.

Typical sleep‑related effects include:

Delayed sleep onset due to heightened discomfort.
Fragmented sleep caused by recurrent itching episodes.
Increased nighttime wakefulness as the scalp becomes more sensitive in a dark environment.
Daytime fatigue and reduced alertness stemming from insufficient restorative sleep.

Managing the symptoms—through topical treatments, regular hair washing, and maintaining a clean sleeping area—helps alleviate the scalp irritation and restores a more stable sleep pattern.

Recognizing Other Signs of Lice

Live Lice on the Scalp

«Size and Color»

Lice bites on the scalp are small, raised eruptions that usually measure between 1 mm and 3 mm in diameter. The lesions are often slightly swollen, with a firm texture that distinguishes them from the surrounding skin.

Pink‑red hue immediately after the bite
Darker reddish‑brown shade as the reaction progresses
Occasionally a pale, almost white center surrounded by a red halo, indicating localized inflammation

The color intensity varies with the individual’s skin tone and the length of time since the bite occurred. Early lesions appear brighter, while older bites may fade to a muted brown. The combination of size and color provides a reliable visual cue for identifying lice‑related irritation on the head.

«Movement Patterns»

Lice navigate the scalp by crawling, climbing, and occasionally jumping short distances, leaving a distinctive pattern of bite marks. The insects favor the hairline, nape, and behind the ears, where skin is thinner and temperature is higher. Their feeding activity produces clusters of red, raised papules that may be grouped or aligned according to the insect’s path.

Typical movement patterns that shape the visual presentation of bites include:

Linear progression: Lice follow a straight route along a hair strand, creating a line of adjacent punctures.
Radial dispersion: From a central feeding site, the insect moves outward in multiple directions, resulting in a star‑shaped arrangement of lesions.
Clustered hopping: When disturbed, lice may jump to nearby hairs, generating tight clusters of bites within a few centimeters.
Sequential crawling: Continuous forward motion along the scalp surface produces evenly spaced punctures at regular intervals.

These patterns help differentiate lice bites from other dermatological conditions, as the distribution directly reflects the insects’ locomotion across the head.

Nits and Empty Shells

«Appearance of Nits»

Nits are the eggs of head‑lice, visible as tiny, oval structures firmly attached to hair shafts. Their length ranges from 0.8 mm to 1.0 mm, making them comparable to the thickness of a pinhead. Fresh nits appear creamy‑white or pale yellow; as they mature, they darken to a tan or light brown hue. The surface is smooth, lacking the flaky texture of dandruff.

Nits are anchored at a shallow angle, usually within 1 cm of the scalp. The attachment point is a solid, cement‑like secretion that resists removal by combing. This cement creates a firm bond that can be felt when tugging a single hair; the egg will not slide down the shaft.

Typical locations include the base of the hair near the crown, behind the ears, and at the nape of the neck. These zones provide the warm, protected environment required for embryonic development. Nits may also be found on short hairs of eyebrows or facial hair, though less frequently.

Distinguishing nits from other scalp debris:

Dandruff: flakes are white, easily removable, and lack a fixed attachment point.
Seborrheic scales: larger, yellowish, and loosely adherent.
Hair‑styling residue: glossy, irregularly shaped, not consistently positioned near the scalp.

The presence of live nits indicates an ongoing infestation. Viable eggs contain a developing embryo that appears as a darker spot within the shell. When the embryo hatches, the empty shell—often called a “shell” or “nitshell”—remains attached and may be mistaken for debris, but its consistent placement and cemented attachment persist.

«Location on Hair Shafts»

Lice bites are most often found where the insects feed directly on the scalp. The feeding sites appear as small, red, raised spots that may itch. Their distribution follows the pattern of hair growth and the areas where lice can grasp the hair shaft.

Base of hair strands, within a few millimeters of the scalp, where the head is warm and blood flow is greatest.
Behind the ears, where hair is dense and the skin is less exposed to air.
Nape of the neck, a region with thick hair and limited sunlight.
Crown area, where hair forms a natural dome and provides easy access for lice movement.
Sideburns and temples, where hair length often extends close to the skin.

In each location, the bite marks align with the hair shaft, forming a line of irritation that follows the direction of hair growth. The lesions may be clustered if several lice feed in close proximity.

«Differentiating Nits from Dandruff»

Lice bites appear as small, red punctate lesions often surrounded by a faint halo of irritation. The surrounding skin may be slightly swollen, and scratching can produce tiny crusted sores. These marks differ from ordinary scalp irritation because they are localized near hair shafts where adult lice feed.

Distinguishing nits from dandruff requires visual and tactile cues. Nits are attached firmly to the hair shaft, usually within a half‑inch of the scalp, and have a cylindrical shape with a glossy, white‑to‑tan color. Dandruff flakes are loose, irregularly shaped, and easily brush off the hair. The following points summarize the key differences:

Attachment: Nits are glued to each strand; dandruff falls off with combing.
Location: Nits cluster close to the scalp; dandruff distributes along the entire hair length.
Shape and texture: Nits are oval, smooth, and slightly translucent; dandruff is flaky, powdery, and matte.
Movement: A gentle pull on a nit will not dislodge it; dandruff will detach readily.
Color change: Fresh nits are creamy; older ones become brownish. Dandruff remains uniformly white or yellow.

When examining a scalp, use a fine‑tooth comb on a well‑lit surface. If the material remains attached after a gentle pull, it is likely a nit. If it slides off and crumbles, it is dandruff. Accurate identification prevents unnecessary treatment and focuses control measures on the true source of irritation.

When to Seek Professional Help

Persistent Symptoms

Lice bites on the scalp often begin as small, red papules that may develop into raised wheals. When the reaction persists beyond a few days, several characteristic signs indicate ongoing irritation.

Continuous redness lasting more than 48 hours, sometimes expanding outward from the original bite site.
Itching that does not subside with over‑the‑counter antihistamines or topical corticosteroids.
Formation of crusted lesions or scabs, suggesting secondary infection or excessive scratching.
Presence of tiny pustules or honey‑colored crusts, typical of bacterial superinfection.
Swelling of the surrounding skin, creating a palpable lump that may be tender to touch.

Persistent symptoms may signal a hypersensitive response to the saliva of the parasite, an untreated infestation, or an accompanying bacterial invasion. Prompt medical evaluation is advisable when any of the above signs endure, as early intervention prevents worsening inflammation and reduces the risk of scarring.

Unsuccessful Home Treatments

Lice bites appear as tiny red papules, often grouped near the hairline, behind the ears, or at the nape of the neck. The lesions may be raised, slightly swollen, and accompanied by intense itching. In some cases, a faint central punctum marks the site where a louse pierced the skin.

Commonly attempted home measures rarely eradicate the problem:

Applying olive or coconut oil and leaving it on for several hours.
Rinsing the scalp with diluted white vinegar or apple‑cider vinegar.
Using over‑the‑counter anti‑itch lotions or hydrocortisone creams.
Sprinkling tea‑tree oil, neem oil, or other essential oils directly onto hair.
Washing hair repeatedly with hot water and shampoo without a nit‑comb.

These approaches fail because they lack ovicidal activity, do not penetrate the cement that secures nits to hair shafts, and merely soothe the itching without removing the insects. Residual eggs hatch after treatment, leading to renewed bites and persistent lesions.

Effective resolution requires products specifically formulated to kill both lice and their eggs, or professional medical intervention.

Widespread Infestation

Lice bites on a heavily infested scalp present as numerous small, red papules. The lesions are usually clustered near the hairline, behind the ears, and at the nape of the neck, but a severe outbreak spreads across the entire head. Each bite may be surrounded by a faint halo of irritation, and scratching often produces a secondary crusted rash.

Typical visual indicators include:

Multiple pinpoint welts, often 1–2 mm in diameter
Linear or irregular patterns following hair shafts
Redness that intensifies after a few hours
Small, raised bumps that may develop a clear center

Accompanying symptoms often involve itching that escalates with heat, a feeling of fullness under the hair, and occasional secondary infection if the skin is broken. The density of bites correlates with the number of live lice and nits present, making the scalp appear uniformly irritated rather than confined to isolated spots.