Trichoscopy / Dermoscopy

What is Trichoscopy (dermoscopy)?

Trichoscopy is a specialized form of dermoscopy focused on the scalp and hair. It uses a handheld device with magnification and polarized light to visualize the scalp surface and hair shafts in detail. This allows dermatologists to see features that are not visible to the naked eye, such as subtle changes in hair shaft thickness, follicle openings, and patterns of regrowth or scarring.

The technique is painless and noninvasive, making it a practical tool in the clinic. Trichoscopy can be performed quickly during a routine visit and does not require any special preparation from the patient. By providing a close-up view of the scalp, it helps clinicians assess the health of hair follicles and identify signs of common hair loss disorders.

Trichoscopy supports the diagnosis of hair loss conditions but is rarely definitive on its own. A thorough medical history, physical scalp exam, and sometimes blood tests or a scalp biopsy may be needed for a complete evaluation. This page explains how trichoscopy works, what to expect during an appointment, and how findings guide next steps for people experiencing hair shedding.

Trichoscopy vs dermoscopy: same tool, scalp focus

Dermoscopy is a general term for using a magnifying device to examine the skin. Trichoscopy refers specifically to the use of dermoscopy on the scalp and hair. While the tool is the same, the focus and interpretation differ: trichoscopy is tailored to assess hair disorders, looking for patterns and changes unique to the scalp and follicles.

In practice, dermatologists may use the terms interchangeably when discussing scalp exams. However, trichoscopy involves specialized knowledge of hair-specific findings, such as hair shaft diameter variability, follicular openings, and regrowing hairs, which are critical for diagnosing hair loss conditions.

What it can and cannot diagnose

Trichoscopy can help identify features suggestive of various hair loss conditions, including telogen effluvium, androgenetic alopecia, alopecia areata, and scarring (cicatricial) alopecias. It is especially useful for distinguishing between diffuse non-scarring hair loss and patterned hair loss.

However, trichoscopy alone cannot always provide a definitive diagnosis. Some findings overlap between conditions, and the technique may not detect underlying medical triggers. In some cases, additional tests such as blood work or a scalp biopsy are necessary to confirm the cause of hair shedding.

Why trichoscopy is used in hair loss

Trichoscopy is a valuable addition to the clinical evaluation of hair loss because it provides immediate visual information that can clarify the type and pattern of shedding. By examining the scalp under magnification, dermatologists can detect subtle differences in hair shaft size, follicle health, and regrowth that may not be apparent during a standard exam.

This technique is particularly helpful in differentiating between common causes of diffuse hair loss, such as telogen effluvium and androgenetic alopecia. For patients, trichoscopy offers a noninvasive way to gather more information about their condition and guide further testing or treatment decisions.

How it supports a scalp exam

During a scalp exam, trichoscopy allows the dermatologist to closely inspect the density and quality of hairs, the appearance of follicular openings, and the presence of regrowing or broken hairs. It can reveal early signs of miniaturization, inflammation, or scarring that are not visible otherwise.

This detailed view helps clinicians document baseline findings and monitor changes over time. It also assists in selecting the best area for a potential scalp biopsy if needed, ensuring the most informative sample is obtained.

How it helps rule in or rule out common causes

Trichoscopy can highlight specific patterns that point toward certain diagnoses. For example, a uniform appearance of hair shafts and preserved follicle openings suggest telogen effluvium, while significant variation in hair shaft diameter and increased single hairs per follicular unit are more typical of androgenetic alopecia.

By identifying or excluding these characteristic features, trichoscopy helps narrow down the list of possible causes and directs further workup, such as blood tests for iron or thyroid issues, when appropriate.

What to expect during a trichoscopy appointment

A trichoscopy appointment is straightforward and usually takes place in a dermatology clinic. The process involves preparation before the visit, the exam itself, and a discussion of next steps after the findings are reviewed. Understanding what to expect can help patients feel more comfortable and ensure the most accurate results.

Patients are encouraged to follow a few simple steps before their appointment, such as washing their hair and avoiding heavy styling products. During the exam, the dermatologist will use a handheld scope to examine different areas of the scalp. Afterward, the findings are discussed, and additional tests or follow-up may be recommended based on the results.

Before the visit (hair washing, products, photos)

To prepare for a trichoscopy exam, patients should wash their hair the night before or the morning of the appointment. Clean hair and scalp make it easier to visualize follicles and hair shafts without interference from oils or styling products.

It is best to avoid heavy conditioners, gels, sprays, or powders on the day of the exam. Bringing photos of hair shedding, a timeline of recent stressors or illnesses, and a list of medications can help the dermatologist understand potential triggers. f

During the exam (handheld scope, contact/non-contact)

The dermatologist will use a dermatoscope or trichoscope, which is a small, handheld device with magnification and light. The scope may be placed directly on the scalp (contact mode) or held just above the surface (non-contact mode), depending on the area being examined and the features being assessed.

The clinician will typically examine several regions of the scalp, including the frontal hairline, crown, and occipital (back) area, to compare findings. The process is painless and does not involve any cutting or sampling unless a biopsy is planned.

After the exam (next steps and follow-up)

After the trichoscopy exam, the dermatologist will review the findings and discuss what they mean in the context of the patient’s history and symptoms. If the results are consistent with a specific type of hair loss, such as telogen effluvium, further testing may not be needed.

In some cases, additional tests such as a blood test, hair pull test, or scalp biopsy may be recommended to clarify the diagnosis or rule out other causes. Follow-up visits may be scheduled to monitor progress or response to treatment.

Key trichoscopy findings in telogen effluvium

Telogen effluvium is a common cause of diffuse, non-scarring hair shedding. Trichoscopy findings in this condition are generally subtle and non-specific but can help support the diagnosis when combined with clinical history and other tests. The most important features are a diffuse pattern of shedding, preserved follicle openings, and a lack of significant miniaturization.

Unlike some other forms of hair loss, telogen effluvium does not cause permanent damage to the follicles. The scalp typically appears healthy, and regrowing hairs may be visible throughout the affected areas.

Typical pattern (diffuse shedding without scarring)

In telogen effluvium, trichoscopy shows a diffuse distribution of hair shedding across the entire scalp. There is no evidence of scarring or permanent follicle loss. The pattern is even, without the patchy or localized thinning seen in some other conditions.

This diffuse pattern helps differentiate telogen effluvium from disorders like alopecia areata, which often presents with well-defined patches, or from scarring alopecias, which show loss of follicular openings.

Hair shaft diameter looks mostly even

A key feature of telogen effluvium on trichoscopy is the uniformity of hair shaft diameter. Most hairs appear similar in thickness, with little variation between them. This contrasts with androgenetic alopecia, where a mix of thick and thin (miniaturized) hairs is seen.

The lack of significant hair shaft diversity suggests that the follicles are functioning normally and that the shedding is due to a temporary shift in the hair cycle rather than progressive miniaturization.

Follicle openings are preserved

Trichoscopy in telogen effluvium reveals that follicular openings remain visible and intact. There are no signs of scarring or closure of follicles, which means the potential for regrowth is preserved.

Yellow dots, representing empty follicles, and upright regrowing hairs may be seen scattered throughout the scalp. These findings support a diagnosis of telogen effluvium when combined with clinical context.

Telogen effluvium dermoscopy vs androgenetic alopecia

Distinguishing telogen effluvium from androgenetic alopecia is a common challenge in dermatology. Trichoscopy provides important clues by highlighting differences in hair shaft diameter, follicular patterns, and the distribution of thinning. Understanding these distinctions is essential for accurate diagnosis and appropriate management.

While both conditions can cause increased shedding, their underlying mechanisms and trichoscopic findings differ. Androgenetic alopecia is characterized by progressive miniaturization of hair follicles, while telogen effluvium involves a temporary shift of hairs into the shedding phase without miniaturization.

Miniaturization and hair diameter variability

In androgenetic alopecia, trichoscopy reveals significant variation in hair shaft diameter, known as anisotrichosis. A diversity of 20% or more is considered diagnostic. This means that both thick terminal hairs and thin, miniaturized hairs are present in the same area.

In contrast, telogen effluvium shows little to no miniaturization. Hair shafts are mostly uniform in thickness, and the overall density may be reduced due to shedding, but the remaining hairs are of normal caliber.

Distribution clues (part line/crown vs diffuse)

Androgenetic alopecia typically affects specific regions of the scalp. In men, this includes the frontotemporal hairline and vertex (crown), while in women, diffuse thinning is seen over the crown with preservation of the frontal hairline. Trichoscopy may reveal reduced triple hairs and increased single hairs per follicular unit in these areas.

Telogen effluvium, on the other hand, presents with diffuse thinning across the entire scalp, without a specific pattern or focus. This even distribution is a helpful clue in distinguishing between the two conditions.

When both can be present at the same time

It is possible for telogen effluvium and androgenetic alopecia to coexist, especially in individuals with underlying genetic susceptibility who experience a triggering event. In these cases, trichoscopy may show both diffuse shedding and areas of miniaturization.

The presence of significant hair shaft diameter variability alongside diffuse thinning suggests a mixed pattern. Additional testing and careful clinical evaluation are needed to guide treatment in these situations.

Trichoscopy hair loss check for miniaturization

A “miniaturization check” is a key part of the trichoscopy exam for hair loss. This assessment looks for changes in hair shaft thickness that indicate progressive follicle shrinking, a hallmark of androgenetic alopecia. The results help determine the underlying cause of shedding and inform treatment decisions.

Miniaturization is not typically seen in telogen effluvium, so its presence or absence can be a critical clue. In some cases, further tests such as a scalp biopsy or laboratory workup may be needed to clarify the diagnosis.

What “miniaturization” means in simple terms

Miniaturization refers to the gradual shrinking of hair follicles, resulting in thinner, shorter, and lighter hairs. Over time, affected follicles produce fine, wispy hairs instead of thick terminal hairs.

This process is characteristic of androgenetic alopecia and can be detected by trichoscopy as increased hair shaft diameter variability. In telogen effluvium, miniaturization is generally absent.

Why the miniaturization check matters for treatment

Identifying miniaturization helps determine whether the hair loss is due to androgenetic alopecia or another cause. Treatments for androgenetic alopecia, such as topical minoxidil, are aimed at slowing or reversing miniaturization.

If miniaturization is not present, as in telogen effluvium, addressing underlying triggers or medical conditions is the priority. The miniaturization check ensures that patients receive the most appropriate and effective management for their type of hair loss.

When a biopsy or labs may still be needed

In some cases, trichoscopy findings are inconclusive or suggest more than one type of hair loss. When the diagnosis remains uncertain, a scalp biopsy can provide definitive information by examining the follicles under a microscope.

Laboratory tests, such as checking for iron deficiency or thyroid dysfunction, may also be recommended to identify medical causes of shedding.

Other scalp conditions dermoscopy can help identify

Trichoscopy is not limited to diagnosing hair loss. It can also reveal signs of scalp inflammation, infection, or trauma. By highlighting specific patterns, trichoscopy assists dermatologists in identifying a range of scalp disorders and planning further management.

Recognizing these additional findings is important, as some scalp conditions may require different treatments or urgent attention. Trichoscopy can help distinguish between non-scarring and scarring alopecias, fungal infections, and hair shaft abnormalities due to pulling or breakage.

Inflammatory scalp disease and scarring clues

Trichoscopy can detect features of inflammatory scalp diseases, such as redness, scaling, and loss of follicular openings. Scarring (cicatricial) alopecias show permanent closure of follicles and may have white patches or irregular dots.

Early identification of scarring is crucial, as these conditions can lead to irreversible hair loss if not treated promptly. Trichoscopy helps guide the need for biopsy and targeted therapy.

Fungal infection and scaling patterns

Fungal infections of the scalp, such as tinea capitis, may produce characteristic scaling, broken hairs, and black dots on trichoscopy. These findings can prompt further testing, such as fungal cultures or microscopy.

Prompt diagnosis and treatment of scalp infections are important to prevent spread and minimize hair loss. Trichoscopy provides rapid, noninvasive clues that support clinical suspicion.

Hair pulling and breakage patterns

Trichoscopy can reveal signs of hair shaft trauma, such as broken hairs, hair casts, and irregular regrowing hairs. These patterns are seen in conditions like trichotillomania (hair pulling disorder) and traction alopecia.

Recognizing these features helps differentiate between self-induced hair loss and other causes, ensuring that patients receive appropriate counseling and support.

Limits of dermoscopy scalp exams

While trichoscopy is a valuable diagnostic tool, it has limitations. Some findings are non-specific or overlap between different conditions, making it challenging to reach a definitive diagnosis based on trichoscopy alone.

Other factors, such as hair color, scalp pigmentation, and prior treatments, can affect the appearance of trichoscopic features. A comprehensive approach that includes history, physical exam, and additional tests is often necessary.

Reasons findings can be unclear

Trichoscopy results may be inconclusive if the scalp is covered with styling products, if there is significant inflammation, or if the hair loss pattern is mixed. Some features, such as yellow dots or broken hairs, can appear in multiple conditions.

In these cases, the dermatologist may recommend cleaning the scalp, repeating the exam, or using additional diagnostic methods to clarify the findings.

When to add pull test, wash test, labs, or biopsy

If trichoscopy does not provide clear answers, other tests can help. The hair pull test and wash test for shedding assess active hair loss. Blood tests can identify underlying medical conditions, such as iron deficiency or thyroid disease.

A scalp biopsy may be necessary if scarring alopecia or an unusual pattern is suspected. Combining these approaches ensures a comprehensive evaluation.

When to see a doctor

Anyone experiencing significant hair shedding, patchy loss, or changes in scalp appearance should seek evaluation by a dermatologist. Early assessment can help identify treatable causes and prevent further hair loss.

Certain warning signs and high-risk situations require prompt medical attention. Bringing relevant information to the appointment can help the dermatologist make an accurate diagnosis and recommend the best course of action.

Warning signs (patches, pain, crusting, rapid thinning)

Seek urgent care if you notice sudden patchy hair loss, pain, swelling, pus, fever, or a rapidly spreading rash on the scalp. These symptoms may indicate infection or inflammatory disease that requires immediate treatment.

Rapid thinning or crusting of the scalp should also be evaluated promptly to rule out scarring alopecia or other serious conditions.

High-risk situations (pregnancy/postpartum, new meds, illness)

Hair shedding can be triggered by major life events, such as pregnancy, childbirth, starting or stopping medications, or recent illness. Postpartum telogen effluvium is a common example, often occurring a few months after delivery.

If you have recently experienced any of these triggers, mention them to your dermatologist.

What to bring to help the dermatologist

To make the most of your visit, bring a list of current and recent medications, any photos of hair shedding or scalp changes, and a timeline of stressors, illnesses, or major events. This information helps the dermatologist identify possible triggers and select the most appropriate tests.

Being prepared ensures a thorough evaluation and increases the chances of finding an effective solution for your hair loss.

FAQ

Does trichoscopy hurt?

No, trichoscopy is a painless and noninvasive procedure. The handheld scope is gently placed on or near the scalp and does not cause discomfort.

Can trichoscopy confirm telogen effluvium by itself?

Trichoscopy can support the diagnosis of telogen effluvium by showing diffuse shedding with preserved follicles and even hair shaft diameter. However, it is not definitive on its own. Clinical history and sometimes additional tests are needed.

What does a “normal” trichoscopy look like in shedding?

In telogen effluvium, trichoscopy typically shows even hair shaft thickness, visible follicle openings, and possibly yellow dots or upright regrowing hairs. There is no evidence of scarring or significant miniaturization.

What is a hair miniaturization check and why is it important?

A hair miniaturization check assesses for thin, short hairs that indicate shrinking follicles, a sign of androgenetic alopecia. This check helps determine the underlying cause of hair loss and guides treatment decisions.

Can trichoscopy tell telogen effluvium from androgenetic alopecia?

Trichoscopy can help distinguish between the two by assessing hair shaft diameter variability and the pattern of thinning. Significant miniaturization and regional thinning suggest androgenetic alopecia, while uniform hair shafts and diffuse shedding point to telogen effluvium.

Do I need to stop minoxidil or hair products before dermoscopy?

It is best to wash your hair and avoid heavy styling products before the exam. You do not need to stop prescribed treatments like minoxidil unless directed by your dermatologist.

When would I need a scalp biopsy if trichoscopy is done?

A scalp biopsy may be recommended if trichoscopy findings are unclear, if scarring alopecia is suspected, or if more than one type of hair loss is present. Biopsy provides definitive information about the follicles.