Dermoscopy - Procedure, Indications, and Contraindications

Introduction:

Skin examination is essential for diagnosis and monitoring treatment efficacy within dermatology. The magnifying glass and good light are helpful for skin examination. However, the human naked eye and the magnifying glass provide a view of only the superficial structure of the skin. A skin biopsy (skin sample is taken and examined under the microscope) is performed for detailed skin examination. However, in recent years, dermoscopy has become common among dermatologists. In the mid-17th century, Peter Borelus and Johan Christophorus Kolhaus first used skin surface microscopy. In the early 20th century, Otfried Muller used monocular and binocular microscopy in clinical practice. In 1920, Johann Saphier, a German dermatologist, first coined the term dermoscopy and outlined the clinical application of skin surface microscopy. Recently, dermoscopy has been used to evaluate non-pigmented skin lesions, such as infectious diseases, inflammatory skin lesions, and non-pigmented skin tumors. The article discusses dermoscopy, its indications, contraindications, procedures, benefits, and side effects.

What Is Dermoscopy?

The evolution of dermoscopy was started in 1663. In 1950, dermoscopy was discovered. In 1971, Dr. MacKie found dermoscopy's advantages in differentiating between cancerous and non-cancerous pigmented lesions. Dermoscopy is also called dermatoscopy, skin surface microscopy, and epiluminescence microscopy. It is a diagnostic technique used to examine the skin by using skin surface microscopy. Dermatoscopy is used to evaluate pigmented skin lesions which are black or brown. Diagnosing a specific skin condition called melanoma (skin cancer) is essential. The high magnifying lens and lightening system are used to evaluate the skin lesions during this procedure.

What Is a Dermatoscope?

A dermatoscope is a handheld instrument used in the dermoscopy procedure to identify skin lesions. This instrument is like a magnifying glass. It comprises a polarized or non-polarized light source, a magnifier, and a transparent plate. In addition, stationary cameras capture the images of the whole body in a single shot. The images are digitally captured. It is also called a digital epiluminescence dermatoscopy. The captured images are analyzed to indicate the position of the skin lesion.

What Are the Types of Dermatoscopes?

Two types of dermatoscopes include hand-held portable and stationary-mounted types.

• Hand-held Dermatoscope: It consists of a transilluminating light source and a magnifying optic. Three modes of dermoscopy include non-polarized light, polarized light-contact, and polarized light-noncontact. Polarized light helps visualize the deep structures of the skin, while non-polarized light allows for the visualization of superficial skin layers.

• Stationary-Mounted Type: During this type, the image of the full body is captured in a single snap. Then, it generates a three-dimensional model of an individual. The specific skin lesions are marked and analyzed by artificial intelligence.

What Is the Procedure for Dermoscopy?

The procedure of dermoscopy includes several steps to ensure the accurate examination and diagnosis of skin lesions. The detailed procedure of dermoscopy is described below:

• Patient Preparation: The healthcare professional should explain the procedure to the patient, including its purpose and side effects. The doctor should also obtain consent from the patient.

• Skin Cleaning: The healthcare provider should clean the skin area to be examined. Then, a fluid such as oil or gel is applied to the skin. It acts as a coupling fluid, reducing reflection and providing clear visualization of the affected area.

• Using a Dermoscope:

  • Contact Dermoscopy: The healthcare provider will place a dermoscopy plate directly on the skin, ensuring that there are no bubbles between the skin and dermoscopy after the application of coupling fluid. Pressure is applied to the dermoscopy to maintain good contact with the skin, ensuring that it does not cause any discomfort to the patient.

  • Non-Contact Dermoscopy: This procedure does not require direct contact with the skin. The healthcare provider should hold a dermoscopy slightly above the skin lesion, and polarized light is used to reduce reflections. The polarized light provides a clear visualization of the affected lesion.

• Adjust Magnification: The healthcare provider should adjust the magnification and light of the dermoscope to obtain a clearer image of the skin lesion.

• Capture Procedure: For full-body imaging, the patient should stand. The camera captures a snap of the patient's entire body in a single shot. The camera then sends the snaps to the backend software, forming a three-dimensional patient image. Artificial intelligence or computer vision algorithms are used to analyze skin lesions. Modern software allows the healthcare provider to add a single skin lesion close-up shot with a dermatoscopy to a specific lesion for better image quality. Later, all the skin lesions are analyzed, and close-up shots that seem suspicious of cancerous skin lesions will be captured.

What Are the Indications and Contraindications of Dermoscopy?

The indications and contraindications of dermoscopy are as follows:

Indications:

• Dermatologists diagnose 65 to 80 percent of melanoma through routine naked eye examination. Dermoscopy improves diagnostic accuracy by ten to 27 percent.

• The procedure is performed when there is a need to differentiate skin lesions from melanoma.

• Dermoscopy is essential to examine moles and other pigmented lesions.

• To identify basal cell carcinoma and squamous cell carcinoma.

• To identify non-cancerous or benign skin lesions.

• To identify inflammatory and infectious skin diseases, such as psoriasis (red and scaly skin) and lichen planus (white lines on the surface of the papules).

• To monitor skin lesions.

• It guides biopsies and assists in determining the margins for surgical skin cancer excision.

Contraindications:

• Active skin infections, such as open wounds and ulcers.

• Highly infectious lesions.

• If the lesion is painful or tender to touch.

• Some patients may be allergic to the coupling fluid. In the case of allergy, alternatives should be used.

• Deep skin lesions.

What Are the Benefits and Side Effects of Dermoscopy?

The benefits and side effects of dermoscopy are as follows:

Benefits:

• Dermoscopy reduces unneeded biopsies.

• Compared to other diagnostic procedures, dermoscopy is inexpensive for most users.

• Dermoscopes are easy to use in which the liquid interface is used, and the healthcare visualizes the structure.

• It is a non-invasive technique.

• It is not time-consuming.

• It allows the observer to concentrate on the lesion.

• It helps differentiate between cancerous and non-cancerous lesions.

Side Effects:

• Some patients may experience pain and discomfort.

• In some patients, coupling fluid may cause allergic reactions and mild skin irritation.

• If the dermoscope is not cleaned or disinfected properly, there will be cross-contamination between patients.

Conclusion:

Dermoscopy is the diagnostic procedure to diagnose pigmented skin lesions. A dermoscope is used to capture images of skin lesions, and artificial intelligence analyzes the lesions. The procedure is painless and non-invasive. The patient should know its benefits and side effects before undergoing the procedure. If the person is experiencing any allergic reaction, they should immediately discontinue the procedure.