The Importance of Linear Trichoscopy

Sir,

Trichoscopy is a noninvasive diagnostic imaging modality that studies credit for its utility in the reliable diagnosis of hair and scalp disorders.[1] Its simple and inexpensive nature allows for widespread accessibility, which is valuable in digital follow-up and monitoring treatment efficacy. Trichoscopy is especially useful in Teledermatology, a subspecialty of dermatology where online video consultations or “store-and-forward” videos allow providers to diagnose, monitor, and treat patients remotely.[2] Digital trichoscopic images may be stored securely to help guide the online management of the disease. With the onset of the COVID-19 pandemic, limitations in face-to-face visits posed by enforced stay-at-home regulations increased the demand for remote alternatives to healthcare.[2] Although useful in optimizing virtual healthcare, traditional trichoscopy is unable to capture large areas in a single image, posing challenges in the holistic evaluation of hair conditions with widespread involvement.[3] Abraham et al. proposed a solution to this technical problem when evaluating entire hairlines in patients with frontal fibrosing alopecia (FFA). A dermatoscope attached to a smartphone in the panorama is moved linearly across the area of interest to capture an all-encompassing image, a process we refer to as “linear trichoscopy” (LT).[4] This provides a more comprehensive analysis on disease state, improving its clinical utility in teledermatology and expanding the list of diseases that can be adequately monitored online.

To illustrate the advantages of LT, we utilized this technique (via iPhone 11; Apple Inc and DELTAone Dermascope, Heine Inc) to monitor two cases, androgenic alopecia involving the frontal hairline [Figure 1] and seborrheic dermatitis involving the eyebrows [Figure 2]. Seborrheic dermatitis commonly affects eyebrows, but due to limitations in traditional trichoscopy, no trichoscopic images of eyebrow seborrheic dermatitis that captures the entire eyebrow in a single image exists in current literature. LT allows for comprehensive observations of areas classically difficult to obtain. Furthermore, when evaluating frontal hairline androgenic alopecia, LT helps identify characteristic hair patterns like frontal scalp hair thinning and retention of the frontal hairline.[5] By providing a widened perspective, LT simplifies the evaluation of disease progression and treatment efficacy compared to traditional trichoscopy. Although we highlight the usefulness of LT in the assessment of common benign hair disorders, we further emphasize the necessity to increase the use of this technique when evaluating more severe disorders like FFA as described by Abraham et al.[4]

Figure 1.

Linear trichoscopy of androgenic alopecia frontal hairline- the presence of the single-hair 93 pilosebaceous units and lower average hair thickness in the frontal area compared to the occiput

Figure 2.

Linear trichoscopy of seborrheic dermatitis in eyebrow- the presence of mild redness with flakiness

In this new age of medicine, constant innovations in technology are necessary for healthcare optimization and minimizing barriers to access of care. This demand is hastened by the consequences posed by the COVID-19 pandemic, which has changed the way we view medicine. LT may pave the way for other technological developments that can aid in the telemedicine movement. Future studies may analyze the utility of combining mobile dermoscopy, where patients use a smartphone-specific dermatoscope attachment, and the panoramic imaging used in LT to improve telemedicine management and telediagnostic accuracy. By granting patients the ability to capture trichoscopic images from home, future studies may evaluate its value in monitoring chronic skin conditions, especially in rural populations with limited access to face-to-face evaluations with a professional.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.