dandruff
Enable an agent to recognise a dandruff presentation, track scalp flaking and its impact, and support appropriate care or reassessment without treating every flaky scalp as dandruff.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a dandruff presentation, track scalp flaking and its impact, and support appropriate care or reassessment without treating every flaky scalp as dandruff.
Dandruff is a common, recurrent scalp condition characterized by excessive shedding of visible skin flakes, sometimes with itching, and little or no clinically apparent inflammation, commonly regarded as the mild end of the seborrhoeic dermatitis spectrum.
It can be Document whether a scalp presentation fits the chosen dandruff definition and retain unresolved alternatives; Compare flaking and itch across observations made under recorded washing and examination conditions; Identify reported associations between flares and scalp products or routines without asserting causation; Support selection and correct use of locally appropriate dandruff care using verified product instructions; Summarise benefit, irritation, recurrence and practical barriers during a care trial; Prepare a focused referral summary when symptoms persist or the presentation challenges the dandruff label.
Distinguishing features
Check for diffuse, fine scalp scale without overt underlying inflammation; this matches the working clinical definition, whereas conspicuous inflammation requires reconsideration. [DermNet](https://dermnetnz.org/topics/seborrhoeic-dermatitis)
Record whether scaling is confined to the scalp or accompanies facial, ear or trunk lesions; additional sites require a linked assessment for a broader condition. [DermNet](https://dermnetnz.org/topics/seborrhoeic-dermatitis)
Check for thick plaques, patchy hair loss or a rash associated with hair products; these observations challenge a simple dandruff interpretation and warrant assessment of alternatives. [NHS](https://www.nhs.uk/conditions/dandruff/)
Establish whether visible particles originate from scalp scaling rather than assuming that any debris in the hair is dandruff; record uncertainty when direct observation is insufficient.
Scope
+ The working definition of dandruff and the evidence supporting its application to a particular scalp presentation
+ Scalp scale appearance, distribution, itch and signs that challenge the dandruff label
+ Episode duration, recurrence and changes relative to washing or product use
+ Reported discomfort, visible shedding and effects on everyday activities
+ Dandruff care history, tolerability, response and reasons for reassessment
- Full modelling of inflammatory or extra-scalp seborrhoeic dermatitis
- Infantile seborrhoeic dermatitis and cradle cap
- Independent diagnosis and treatment models for psoriasis, tinea capitis, contact dermatitis and head lice
- Hair loss disorders and hair shaft diseases
- Shampoo formulation, manufacturing and regulatory authorisation
- Malassezia taxonomy and scalp microbiome ecology beyond their relevance to a dandruff assessment
Characteristics
- Dandruff label basis
- self-reported; observer-suspected; clinician-assessed; disputed; unknown Separates use of a familiar name from an assessed scalp condition.
- Scalp scale appearance
- fine or coarse; loose or adherent; white, grey or yellowish; dry-looking or greasy-looking; mixed; unobserved Makes the presentation inspectable without using flake colour or oiliness alone as a diagnosis.
- Scalp scale extent
- Estimated percentage of examined scalp, with examined regions and method recorded Allows comparison of extent while distinguishing incomplete examination from absent scale.
- Overt scalp inflammation
- absent; present; uncertain; not assessed, with observed colour change, swelling or tenderness Tests the boundary of the working dandruff definition.
- Itch intensity
- Self-reported 0-10 rating with explicit anchors and recall period Tracks symptom burden separately from visible scale; the rating is a proposed recording convention, not a diagnostic threshold.
- Time since last scalp wash
- Hours or days Provides context for comparisons of visible flaking.
- Episode course
- newly observed; persistent; improving; cleared at observation; recurrent; unknown Distinguishes a current appearance from the longer course.
- Related skin assessment
- Link to suspected or assessed seborrhoeic dermatitis or another scalp condition, with assessor and date Preserves neighbouring diagnoses without duplicating their models.
- Care exposure
- Linked product or care episode with ingredient, formulation, instructions, actual use and dates Makes response interpretable in relation to what actually reached the scalp.
- Everyday impact
- Reported effects on comfort, clothing choices, social activity, sleep or grooming, each with severity and timeframe Allows care goals to reflect the person's priorities.
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.dandruff
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 17 findings · 27 questions.
Dandruff identity and boundaries Establish what the dandruff label means in this record and whether the observed presentation fits it.
A familiar symptom label can conceal different scalp conditions and different definitions.
Meaning of dandruff
Record the definition used and who applied it.
Working clinical sense
Use scalp scaling without overt inflammation as the working sense, while retaining the original label and its provenance. DermNet describes dandruff as an uninflamed scalp form of seborrhoeic dermatitis. [DermNet](https://dermnetnz.org/topics/seborrhoeic-dermatitis)
- Does dandruff here mean an assessed scalp condition or the person's description of visible flakes? definition
- Who applied the label, when, and using which definition or examination? provenance
Neighbouring scalp conditions
Capture observations that support or challenge the label.
Boundary-changing observations
Retain inflammation, plaques, hair changes, extra-scalp lesions and product-associated rash as reasons to consider a neighbouring condition rather than silently broadening this model.
- Which observed features challenge uncomplicated dandruff, and which alternatives remain unresolved? boundary
- Should this record link to a broader seborrhoeic dermatitis assessment or another scalp-condition model? action
Scalp flaking and symptoms Describe scalp scale and the symptoms accompanying it.
Flake visibility, scalp involvement and discomfort are different dimensions of the presentation.
Scale pattern
Describe scale directly on the scalp and shedding into hair or onto clothing.
Observable scale burden
Record scale appearance, adherence and examined scalp regions, keeping directly observed scalp scale separate from reported shedding.
- Where is scale visible, what does it look like, and how much of the scalp was examined? measurement
- Was the assessment made before or after washing, brushing or applying scalp products? provenance
Itch and scalp integrity
Record symptoms and visible damage separately from scale.
Symptom and damage profile
Capture itch, burning, tenderness and scratching-related damage as individual observations rather than combining them into an unexplained severity label.
- How intense and frequent is the itch, using what scale and recall period? measurement
- Are burning, tenderness, broken skin or other findings present that require separate assessment? boundary
Flare course and scalp context Locate flaking episodes within the person's scalp-care history.
A single observation cannot establish persistence, recurrence or a relationship to a changing routine.
Episode timeline
Distinguish onset, persistence, improvement and return of flaking.
Recurrence pattern
Record dated observations and reported intervals with reduced or absent flaking, preserving uncertainty about unobserved periods.
- When was flaking first noticed, and which subsequent periods were persistent, improved or apparently clear? measurement
- Is the episode history supported by dated observations or retrospective recall? provenance
Washing and product context
Record scalp exposures that may affect appearance, comfort or interpretation.
Reported flare associations
Track changes in washing, shampoos, dyes, styling products and other reported circumstances as candidate associations, without assigning an individual cause.
- Which routine or product changes preceded worsening or improvement, and by how long? provenance
- Does the timing suggest a product reaction or residue that needs assessment beyond dandruff? boundary
Dandruff care and response Connect a defined care trial with actual use, tolerability and outcomes.
A claim that a shampoo worked or failed is difficult to interpret without knowing the product and how it was used.
Care trial definition
Identify the intervention and the applicable instructions.
Product and use record
Record the exact dandruff product, active ingredient, instructions and actual use. NHS guidance recommends following the selected shampoo's instructions. [NHS](https://www.nhs.uk/conditions/dandruff/)
- Which product and formulation were used, with what frequency, scalp contact time and duration? measurement
- Which current label or professional recommendation establishes appropriate use for this person? provenance
Benefit and tolerability
Assess change against baseline while accounting for exposure and adverse effects.
Interpretable care outcome
Compare scale, itch and tolerability at a planned review; retain missed applications and simultaneous product changes as limits on interpretation.
- What changed in scale and itch relative to baseline, and were observation conditions comparable? measurement
- Does the observed benefit, irritation or uncertain exposure support continuing, reviewing instructions or seeking professional reassessment? action
Daily burden and reassessment Connect dandruff observations to personal goals and decisions about further assessment.
Visible shedding can matter independently of itch, while persistent or atypical symptoms may require a different care pathway.
Visible shedding and care burden
Record what the person wants to improve and what care is practical.
Person-defined improvement
Capture priorities such as less visible shedding or less itch alongside the cost, time and hair-care compatibility of the routine.
- Which consequence of dandruff matters most to the person, and what change would they consider worthwhile? definition
- Which aspects of the care routine are difficult to maintain with their usual washing and styling practices? action
Reassessment triggers
Make reasons for professional review explicit.
Persistent or atypical presentation
NHS advice supports medical review when dandruff persists after a month of anti-dandruff shampoo use, is severe, or accompanies marked itch, redness or swelling. Store the applicable review advice and observed trigger. [NHS](https://www.nhs.uk/conditions/dandruff/)
- Has the applicable review point been reached, or have symptoms emerged that justify earlier assessment? action
- Which observations, product exposures and treatment responses should accompany the referral? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The boundary between dandruff and seborrhoeic dermatitis varies across clinical and research usage.
- Malassezia yeasts, sebum and individual scalp susceptibility are implicated; dandruff is not adequately explained as a simple fungal infection or poor hygiene.
- This is recalled knowledge without source verification; confirm coding details and measurement instruments before formal publication.
- Which of these check these first hold for the sense of dandruff this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- ICD-10 - L21.0 - WHO category for seborrhoea capitis, which includes dandruff; national coding adaptations should be checked.
- Which of these identifiers and schemes hold for the sense of dandruff this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- A clinical description for scalp flaking with minimal visible inflammation.
- A target condition for anti-dandruff shampoos and other scalp-care products.
- A research phenotype for studying scalp barrier function, sebum and interactions with Malassezia yeasts.
- Which of these real-world use hold for the sense of dandruff this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Scalp flaking severity - Instrument-dependent; assessed with visual grading scales without a universal range. - Ordinal score
- Itching intensity - 0-10 when a numerical rating scale is used. - Patient-reported score
- Which of these typical measurements hold for the sense of dandruff this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Scratching can cause excoriations and occasionally secondary infection.
- Scalp psoriasis, contact dermatitis or tinea capitis can be mistaken for dandruff.
- Scalp products can cause irritation or allergic contact dermatitis.
- Visible flakes and persistent itching can cause embarrassment and reduce quality of life.
- Which of these failure modes and hazards hold for the sense of dandruff this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Anti-dandruff products may be regulated as cosmetics or medicines depending on jurisdiction, ingredients and claims.
- Which of these regional variation hold for the sense of dandruff this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Seborrhoeic dermatitis - Prominent inflammation and involvement of other sebaceous areas support seborrhoeic dermatitis; dandruff usually denotes minimally inflamed flaking confined to the scalp.
- Scalp psoriasis - Well-demarcated plaques, thicker scale and psoriasis elsewhere support psoriasis, although overlap can occur.
- Tinea capitis - Dermatophyte infection involving scalp hair, often with broken hairs or patchy hair loss and supported by fungal testing, separates it from dandruff.
- Scalp contact dermatitis - An irritant or allergic reaction associated with an exposure, usually with inflammation, distinguishes it; patch testing can support an allergic cause.
- Dry scalp - Dry scalp describes reduced hydration and can cause flaking, but flaking alone does not establish dandruff or distinguish the two.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of dandruff this model covers, and on what evidence? provenance
What the second pass must settle
- Which operational boundary should Vercy adopt between dandruff and inflammatory scalp seborrhoeic dermatitis, and how should broader source terminology map to it?
- Which dandruff scale-scoring method is sufficiently reliable across hair textures, skin tones and washing intervals for comparable longitudinal records?
- What magnitude and duration of improvement in flaking or itch should count as a meaningful response rather than temporary scale removal?
- How should individual contributions from Malassezia activity, scalp barrier properties and sebum be represented when their causal importance has not been established for that person?
- Which age-specific and jurisdiction-specific care and referral rules should be attached to this model through maintained clinical references?