How a Trichoscopy Exam Is Performed, Step by Step
How is a trichoscopic examination performed, from patient preparation to the scalp regions imaged?
Most people picture trichoscopy as pointing a camera at a scalp, but the picture is the easy part. What makes it diagnostic is doing the same thing the same way every time: clean dry hair, the same regions, the same magnification, the same notes. Get that discipline right and you've got a record you can hold up against a visit six months from now; get it wrong and you've got holiday snaps.
- History and naked-eye survey: You look first and confirm second, because trichoscopy quantifies a suspected pattern rather than hunting blindly.
- Preparation check: Clean, dry, product-free hair, with recent dyeing or a same-day wash noted in the record rather than ignored.
- Part and place: You part the hair to expose scalp skin and rest the instrument on it, or just above it.
- Choose the optics: Dry to keep surface scale and shaft texture, immersion to open up vessels and pigment, stepping from about 10x for pattern to 20x to 70x or higher for shaft calibre and counts.
- Work the regions in order: Frontal, vertex, temporal, occipital, plus any abnormal patch, and record what you can count at each site.
- Anchor the sites: Each one is referenced to a fixed landmark and shot at the same distance and orientation so the next visit is a comparison, not an impression.
A trichoscopic examination is a painless, non-invasive session that clinics commonly allow ten to twenty minutes for, imaging the frontal, vertex, temporal, and occipital scalp at roughly 10x to 70x or higher on clean, dry, product-free hair, with the occiput acting as the internal control.
What equipment and magnification levels are used for a trichoscopic examination?
Two instruments cover nearly all scalp work, and they aren't rivals. The handheld gets you across four regions in a couple of minutes; the video system is what turns what you saw into a number somebody can check next year.
A handheld dermoscope works at roughly 10x for pattern recognition while a videodermoscope steps from about 20x through 50x, 70x, and in some systems 100x to 200x or beyond, and only a calibrated field of view turns those images into hairs per square centimetre and micrometres of shaft diameter.
How should a patient prepare their hair and scalp before a trichoscopy appointment?
Anything sitting on the scalp surface or coating the shaft ends up in your image, and in the image it looks like pathology. Keratin fibres cling to shafts and read as debris, powders settle into the openings and imitate scale, oils flatten and glaze the whole surface. So the instructions you hand a patient aren't fussiness, they're the difference between a reading and a guess.
- Wash timing: Shampoo the day before, not the morning of the appointment.
- Product blackout: Stop fibres, powders, dry shampoo, and heavy oils for two to seven days.
- Colour gap: Disclose recent dye or bleach; where the visit can wait, book two to four weeks after.
- Arrive loose: Extensions, wigs, and tight braids out, and bring medications, dates, and old photographs.
Hair should arrive clean, dry, loose, and free of fibres, powders, dry shampoo, and oils for roughly two to seven days beforehand, with washing done the day before rather than the same morning.
When is dry trichoscopy used instead of immersion trichoscopy?
You aren't picking a house style here, you're deciding site by site. Dry keeps the surface exactly as it is, scale and casts and crusting and cosmetic residue included, which is why it's the default for the opening survey and for anything inflammatory. Immersion kills the light scatter at the stratum corneum and lets the beam reach deeper, which is where scarring and non-scarring processes part company.
| What you're after | Dry | Immersion |
|---|---|---|
| Surface scale and casts | Preserved as found | Dissolved and flattened |
| Vascular architecture | Lost behind glare | Clearly visible |
| Interfollicular pigment | Partly masked | Readable |
| Coupling medium | None | Alcohol gel, ultrasound gel, water |
| Best use | Opening survey, scaling and inflammatory scalps | Vessel and pigment reading, scarring questions |
Dry trichoscopy is the default for surface features such as scale, casts, and shaft texture, while immersion with alcohol gel, ultrasound gel, or water reveals vascular architecture and interfollicular pigment, so any site that matters is imaged dry first and then wet.
Which scalp regions are imaged during a standard trichoscopy examination, and why those?
Trichoscopy diagnoses by comparison, so the regional map is the method, not the paperwork. Run the same order every time, frontal then vertex then temporal then occipital, and add any active patch, itchy spot, or expanding border on top, because a fixed sequence is what stops a region getting quietly skipped on a busy day.
- Mid-frontal, two to three cm behind the hairline: Where miniaturisation and single-hair units show up first.
- Vertex or mid-scalp: Separates a patterned loss from a diffuse one, clearest along a woman's central part.
- Temporal, both sides: Traction, male recession, and the receding band of a fibrosing pattern.
- Occipital, low at the back: Imaged every single time as the patient's own internal control.
The standard set is four regions, mid-frontal, vertex, temporal on both sides, and occipital, with the occiput imaged in every case as the internal control because androgenetic loss largely spares it.
How does a clinician mark and record a site so follow-up images can be compared?
Hair changes slowly, and the change worth catching is smaller than the error a sloppy retake will invent. Shift a couple of centimetres toward the vertex on a patterned loss and you'll manufacture a decline; drop the probe a millimetre closer and you'll manufacture an improvement. Neither one looks any different from a real treatment effect once it's in the chart.
- Anchor to bone, not to hair: A measured distance from the glabella along the midline, from the tragus, or from the occipital protuberance, written down as a number rather than as "roughly on the crown."
- Mark the spot for the session: A temporary tattoo dot, a surgical marker, or a small clip, and in some clinics a tiny target area trimmed to uniform length so shaft length doesn't skew the count.
- Lock the geometry: Same contact plate or spacer, same magnification, same probe orientation to the growth direction, same lighting mode.
- Stamp the file: Patient identifier, date, region name, magnification, lighting mode, and whether the view was dry or immersion.
Every site is defined by a measured distance from a fixed anatomical landmark and re-imaged at the same magnification, orientation, and lighting mode, with follow-up typically set at four to six months for early response and six to twelve months thereafter.
What measurements are recorded during the examination, such as hair counts and shaft diameters?
Numbers are what separate a trichoscopic record from a photograph, and the useful ones are always regional. A single whole-scalp density figure hides the frontal-to-occipital gradient that carries the entire diagnosis.
Shaft diameter diversity above twenty percent of hairs in a region is treated as diagnostic of an androgenetic process in men and above ten percent in women, read against a healthy adult density that commonly falls between about 150 and 250 hairs per square centimetre.
How long does the examination take and what does the patient experience during it?
For the patient this is about as undemanding as a clinical examination gets, because nothing is cut, injected, or numbed. What they feel is hair being parted repeatedly and a smooth plate resting on the skin, plus the cool slip of gel where you need an immersion view, and an inflamed or scratched scalp can sting briefly from alcohol-based media, which is a reason to switch medium rather than skip the view. Afterwards the gel wipes out, the hair looks slightly damp or flat for an hour, and they go straight back to work.
A focused trichoscopy of the four standard regions takes five to ten minutes and a fully documented video assessment fifteen to thirty, inside a typical appointment of forty-five to sixty minutes, with no anaesthesia, no incision, and no recovery period.
What artifacts and technique errors can distort trichoscopic findings?
Most misreadings in trichoscopy aren't failures of knowledge, they're failures of technique, and you'll make them confidently. The expensive one is pressure: lean on the probe and you blanch the exact capillary loops you switched to immersion to see, then record a pale, vessel-poor scalp that doesn't exist. Ask about products and treatments before you look, use a light touch, and image the active edge of anything that has an edge.
- Cosmetic residue: Building fibres read as casts; powders and dry shampoo imitate scale and dots.
- Probe pressure: Firm contact blanches perifollicular vessels and fakes a vessel-poor scalp.
- Wrong site: An old patch's centre is often inactive; the diagnostic features sit on the border.
- Kit and colour limits: Gel bubbles, glare, a smeared plate, and very pale or grey hair all corrupt counts.
Pressing the contact plate firmly blanches the perifollicular vessels and records a falsely pale, vessel-poor scalp, which is why vascular assessment calls for a light touch or a non-contact polarised view.
What hygiene, consent, and documentation requirements apply to scalp imaging?
Non-invasive doesn't mean unregulated. You're touching scalp skin with a shared instrument and creating identifiable health records at the same time, and each of those carries its own obligations. Treat the images the way you'd treat any other part of the chart, because legally that's exactly what they are.
- Disinfect between every patient: Clear gel and hair off the plate, then wipe with alcohol at sixty to ninety percent, left in contact long enough to work and used within the manufacturer's guidance, since some coatings and polarising filters degrade under harsher agents.
- Escalate on broken or infected skin: Single-use barrier film over the plate, single-use coupling medium instead of a shared bottle, gloves, and a non-contact polarised view wherever the diagnosis allows.
- Take consent before you capture: Record what's being photographed, why, and that the images form part of the clinical record.
- Keep secondary use separate: Teaching, presentation, publication, and before-and-after promotion each need their own withdrawable permission, never one bundled tick on the treatment form.
- Store and retain to record standard: Access-controlled systems with an audit trail and secure transfer, and a retention policy that genuinely holds the baseline for as long as you plan to compare against it.
The contact plate is cleaned and disinfected between every patient with alcohol at sixty to ninety percent, and consent to capture is obtained and recorded before imaging, with teaching, publication, and promotional use each requiring separate, withdrawable permission.
