Melasma is a common facial skin pigmentation spot. It not only destroys the evenness and radiance of the skin, but may also cause low self-esteem and anxiety in patients, especially in social situations.
Dermoscopy can clearly observe the characteristics of melasma such as the distribution of pigment granules, morphology and borders, which helps doctors to determine the type and severity of melasma more accurately. Compared with the traditional naked eye observation, dermoscopy can reduce the errors caused by subjective judgement and improve the accuracy of diagnosis.

Overview of Melasma
Melasma is a common hyperpigmented skin disorder. It has a slow course and often has no other discomfort, but it seriously affects the skin’s aesthetics. The causes of melasma are complex and diverse, involving heredity, ultraviolet radiation, sex hormones, air pollution, mental and psychological factors, poor quality cosmetics, heat exposure and systemic diseases.
Melasma can be classified into the following types: epidermal, dermal, mixed and inflammatory. Ultraviolet rays are an important factor affecting melasma with prolonged exposure to sunlight, especially without cover. UV rays can damage the skin’s barrier function and cause an increase in melanocytes, which in turn leads to melasma.

Principles of Dermoscopy
Dermoscopy is a non-invasive procedure that does not require cutting or sampling of the skin and therefore does not cause pain or trauma to the patient. Dermoscopy is able to magnify and visualise skin structures that are difficult to observe with the naked eye, enabling doctors to more accurately observe and analyse the characteristics of skin lesions.
Dermoscopy is able to clearly display the morphology, colour and structural features of skin pigmented lesions, which helps doctors to more accurately determine the nature and type of lesions. For example, when distinguishing between melanoma and benign nevus, a dark pigmented nevus will show obvious uneven pigmentation and different shades under dermoscopy.

Dermoscopy Procedure for Melasma
Before the start of dermoscopy, the patient needs to clean the skin surface to be examined in advance, and inform the doctor if there is any local inflammation or breakage, so that the doctor can assess the suitability of dermoscopy. During the examination, the doctor will put the probe of the dermatoscope on the surface of the skin lesion that needs to be observed, keeping a good distance between the probe and the skin. Adjust the light source and magnification of the device until the picture is clear. The doctor will select representative areas of melasma for examination, including the edges and centre of the lesion as well as the surrounding normal skin areas for comparative analysis.

Dermoscopic Features of Melasma
Typical dermoscopic manifestations of melasma are pseudopigmented networks of light to dark brown or greyish-blue patches, dots, globules, and curved or ring-shaped structures. Other dermoscopic features include capillary dilatation and thickening and darkening of cuii hair.
Dermoscopy can be used to differentiate melasma from other facial pigmented disorders. The following are the differences between melasma and other pigmented lesions:
Freckles: appear dermoscopically as round or oval light brown patches and brown punctate structures with well-defined borders.
Riehl’s melanosis: dermoscopically it shows a pseudopigmented network and blue-grey globules, capillary dilatation is seen in almost all lesions, and scaling is visible in some lesions.

Tips for Analysing Dermoscopic Images of Melasma
Observing the distribution of pigment in dermoscopic images allows one to determine the level and extent of pigment deposition. For example, when melanin when located at the true epidermal junction, it appears dermoscopically as dark or light brown. Observing the clarity of the borders of areas of pigmentation can help determine the type and staging of melasma. For example, the epidermal type of melasma usually has clear borders, whereas the dermal or mixed type may have fuzzy borders.
Regular monitoring with dermoscopy during the course of treatment allows for observation of changes in melasma, including reduction in pigmentation, change in pattern, and definition of borders. These changes can be used as a basis for assessing the effectiveness of the treatment.

Diagnosis and Differential Diagnosis of Melasma
To accurately differentiate dermal melasma from epidermal melasma, more specialised investigations such as histopathology are usually required. Dermoscopy can serve as a pre-diagnostic aid by optically magnifying the lesions. Melasma does not usually turn into melanoma. Melasma is a pigmentation. Melanoma is a malignant tumour caused by an abnormal proliferation of melanocytes. Although both involve hyperpigmentation, their pathological mechanisms and prognosis are very different.

Dermoscopy in Melasma Treatment
With dermoscopy, doctors can see the minuscule structures of the skin, determining the type and severity of skin lesions. Epidermal melasma may require a superficial peel, whereas dermal melasma may require a deeper laser treatment or medication.
Dermoscopy images at regular intervals allow clinicians to monitor the activity of the lesions and their treatment response, and to anticipate treatment outcomes. During the course of treatment, subsequent melasma dermoscopic images would show a progressive improvement in the degree of hyperpigmentation, with even distribution of pigment and clearer borders of the areas of hyperpigmentation over time.

Modern Methods of Melasma Treatment combined with Dermoscopy
The shape, extent and depth of the skin lesion dermoscopically is made so clear which helps the doctor to figure out what area needs to be specifically targeted for laser treatment. This allows to make the laser treatment more accurate sparing the adjacent normal skin. With the application of dermoscopy, the microstructure of the skin lesion can be observed, which will lead the doctor to diagnose the severity of the lesion and, therefore to choose the correct topical medication.
During treatment, dermoscopy can be used to dynamically monitor changes in the lesion. If the treatment is ineffective or the condition deteriorates, the doctor can optimise the treatment plan in time.

Melasma Patient Education and Self-monitoring
Patient understanding of the causes and typical symptoms of melasma will help patients to detect changes in their condition and take appropriate treatment measures. If you wish to use dermatoscope for home skin inspection, then IBOOLO dermatoscope will be your first choice, we will teach you how to operate it with DE-4100 as an example. First the area of however the skin to be examined is cleaned up, after which the dermatoscope magnet is connected to the mobile phone and the camera of the mobile phone is activated. Focus the image until it’s clear, then take a picture to document the event.

Limitations and challenges of dermoscopy
The patient’s skin colour, skin texture and skin type can affect dermoscopic observation. Inadequate or uneven lighting may result in blurred or distorted dermoscopic images. Prior to dermoscopy, patients should carefully clean the skin lesion area to ensure that there is no makeup or skin care product residue. Choose a place where the light is bright and even to perform the dermoscopy.

The key role of dermoscopy in the diagnosis and management of melasma
Dermoscopy contributes to a better visualisation of the deeper components of the skin and assists in the accurate diagnosis of a melasma, including its type, size and distribution, in order to establish more targeted treatment. Doctors can differentiate melasma with other pigmented skin diseases using dermoscopic image analysis and can avoid misdiagnosis after that. Dermoscopy is a promising approach to improving the diagnostic accuracy and efficiency of melasma and other skin diseases with continuous education and technological innovation as important drivers for the continuous development of dermoscopy.