Dermoscopy of Lichen Planopilaris

The clinical significance of lichen planopilaris is mainly reflected in the impact on patients’ quality of life. It can lead to patchy or diffuse baldness of the scalp, which not only affects the patient’s appearance, but may also have a negative impact on the patient’s mental health. Early and accurate diagnosis of lichen planopilaris can help to take timely treatment measures to slow down the progression of the disease and reduce the area of hair loss. Dermoscopy can clearly observe the characteristic lesions such as erythema, desquamation, follicular hyperkeratosis, and clustered spiny follicular papules around the hair follicles of patients with lichen planopilaris, which can provide an intuitive and accurate basis for the diagnosis of lichen planopilaris.

What Is Lichen Planopilaris?
Lichen Planopilaris, also known as trichophytic lichen planus, is a form of primary lymphocytic scarring alopecia that mainly effects the scalp. The exact cause of tinea versicolor is unknown, but it may be the result of a variety of issues including immune system abnormalities, genetic factors, fungus on your skin and emotional stress.
Lichen planopilaris mainly shows patchy alopecia or diffuse hair loss on the scalp, with active lesions at the margins of bald patches including perifollicular erythema and desquamation with follicular hyperkeratosis. Associated symptoms include pruritus and pain, which are various in severity.

Epidemiology and Classification of Lichen Planopilaris
The incidence of lichen planopilaris is relatively low worldwide, with a reported prevalence of about 1%. More often than men followed by women, this disease is present in the age bracket of 30 to 70 years old. Lichen planopilaris can be classified into the following types or subtypes based on their clinical presentation and pathologic features: classic lichen planopilaris, frontal fibrosing alopecia, and Graham-Little-Piccardi-Lasseur syndrome.

Dermoscopy in the Diagnosis of Lichen Planopilaris
Dermoscopy is an optically based dermatologic diagnostic tool that focuses on magnifying the surface of the skin through the use of an optical magnification system so that the physician can see the texture and details of the skin surface more clearly. Dermoscopy also improves the contrast and clarity of the image through the use of optical filters and color filters.
Lichen planopilaris is a chronic inflammatory skin disease that primarily affects the hair follicles of the scalp. It has some characteristic manifestations under dermoscopy, such as erythema around the hair follicles, punctate hemorrhage at the mouth of the hair follicles, and atrophy of the scalp, which can help doctors to make a differential diagnosis. Meanwhile, dermoscopy, as a non-invasive means of examination, can observe the characteristics of lesions without damaging the skin, reducing the pain and discomfort of patients.
Prior to dermoscopy, patients should avoid applying medications or cosmetics to the skin surface prior to the examination, and especially avoid applying sunscreen and other substances that may block light from the imaging. During the examination, the patient should try to cooperate with the examiner and assume the proper position so that the skin lesions can be fully exposed. After the examination, patients need to pay attention to keep the local skin clean and dry, and avoid scratching the affected area, so as not to cause skin infection.

Dermoscopic Features of Lichen Planopilaris
Absence of follicular openings: In advanced lesions of Lichen Planopilaris, the follicular openings may be completely absent, resulting in visible patches of alopecia on the scalp.
Perifollicular erythema: In active lesions, perifollicular erythema can be observed, and these are usually accompanied by signs of desquamation and follicular hyperkeratosis.
Classic white and blue-gray spots: On dermoscopic examination, Lichen Planopilaris may exhibit irregular white spots between hair follicles and bluish-gray spots around hair follicles.
White scarred areas: Areas of white scarring usually form as a result of complete loss of hair follicles and fibrosis of the skin, and are typical of advanced stages of lichen planus.
Milky red areas: On dermoscopy, localized congestion or vasodilatation due to an inflammatory response may be observed, and these usually appear as red or pink areas.

Lichen Planopilaris and Other Alopecia Areata Disorders
Lichen Planopilaris differs significantly from other alopecia areata disorders (e.g., discoid lupus, frontal fibrotic alopecia) in terms of dermoscopic features. Dermoscopy is able to magnify the area of skin lesions, details of skin surface microstructure, hair shaft morphology, and capillaries, providing visual evidence for differential diagnosis.
Lichen Planopilaris: Dermoscopy reveals a marked inflammatory reaction around the hair follicle in the form of erythema, edema, or desquamation, and these changes are distributed around the hair follicle in a ring or target-shaped pattern. The follicular opening may become inconspicuous or disappear completely, and sometimes the follicular opening can be seen to be blocked by keratin plugs.
Discoid Lupus: The follicular opening is seen as a distinct red spot, which is often surrounded by a white halo. In advanced lesions, due to fibrosis of the dermis, white structureless areas are seen dermoscopically; these areas correspond to scar tissue in the dermis.
Frontal Fibrotic Alopecia: There is a marked reduction in the number of hair follicles in the frontal region, especially the reduction of coarse hairs. Erythema around the hair follicles may be present in the area of hair loss. The forehead skin may become smooth and tight, losing normal skin texture and elasticity.

Case Study
Clinical and dermoscopic images of lichen planopilaris are shown below respectively.

By comparing the clinical and dermoscopic images of lichen planopilaris we can see that the dermoscopic images show the fine structure of the follicular units more clearly. The dermoscopic image shows scales around the hair follicle as well as a hair tube pattern, and keratinous plugs are visible at the follicular openings, which are due to hyperkeratosis and blockage of the follicular openings with large amounts of keratinized material. Blue-gray spots around the hair follicles, forming target-like pigmentation, are typical features of lichen planopilaris, and the doctor can make a preliminary judgment of the disease based on them.
Dermoscopy is an important tool for initial diagnosis, but pathologic examination remains the gold standard for diagnosis. For patients with suspected LPP, pathologic examination should be performed as early as possible to confirm the diagnosis and reduce the possibility of misdiagnos.

Treatment and Management of Lichen Planopilaris
The treatment of lichen planopilaris mainly includes medication, physical therapy and surgery. Patients should eat more fresh vegetables, ensure enough sleep and face the disease with an optimistic attitude to help the disease recover. After treatment, doctors should closely observe whether the patient’s symptoms are reduced. According to the improvement of the patient’s rash, it will be categorized into four grades for evaluation: cured, obvious effect, effective and ineffective.
Lichen planopilaris is a chronic disease that requires long-term management and treatment. Patients should take the medication on time as prescribed by the doctor and should not stop taking the medication or change the dosage at will. Health education should be strengthened to improve patients’ knowledge of the disease and self-management ability.