A dermatoscope also called a dermoscope, is a handheld device or machine with an achromatic (white-light) 10-14 fold magnification lens that allows 100% of the viewing area to be in focus. Early dermatoscopes required oil immersion (oil between the dermatoscope and skin) to reduce light artifacts such as reflection and refraction, but newer models use polarized filters to reduce these artifacts.
Dermoscopy is a non-invasive diagnostic method using a dermatoscope to magnify the skin 10-14 times in such a way that colour and patterns of the subsurface structures become visible. Usually this will not be visible with the naked eye.
It is mainly used in dermatology to evaluate pigmented lesions in order to distinguish cancerous(malignant) skin lesions from benign (non-cancerous) skin lesions. Malignant pigmented skin lesions are usually melanomas and or pigmented basal cell carcinomas. Benign pigmented lesions are commonly melanocytic nevi or mole, seborrheic keratosis, or aging spots and sunspots amongst many.
Dermoscopy is not only used for pigmented lesions but can also be used for other skin lesions including inflammatory lesions like psoriasis, vascular lesions, and other skin growths whether cancerous or noncancerous. A dermatoscope is also very helpful in the examination and diagnosis of hair and nail disorders.
Pictures of the lesions can be taken when a phone or other forms of cameras are attached to the dermatoscope. These pictures can then be useful in the future to compare for changes happening in those lesions, especially for pigmented lesions. Dermoscopic examination significantly increases the accurate and early diagnosis of melanomas when used by a doctor especially a dermatologist trained in its use.