ABSTRACT
With a clinically well-trained eye and accurate patient history, most skin lesions can be diagnosed with simple visual inspection. Wood's lamp was invented in 1903 by Robert W. Wood (1868–1955), an American physicist. Its first use in dermatology was described by Margarot and Deveze in 1925 for the detection of hair fungal infection. Wood's light (WL) is a source of ultraviolet (UV) light generated by a high-pressure mercury arc fitted with a compounded filter made of barium silicate with nickel oxide (Wood's filter). Melanin absorbs light emitted by WL, so a lesion with an increased concentration of melanin in the epidermis appears darker than the surrounding normal skin. The use of WL also helps in the detection of chemically induced leukoderma and leukoderma associated with melanoma. There are some bacteria and fungi that produce fluorescent compounds that can be identified with WL, enabling an early diagnosis of some disorders.
