Wood's lamp is a medical device used to diagnose vitiligo by emitting long-wave ultraviolet light at 320-400 nm through a filter containing nickel hydride and irradiating it onto the affected area of leukoplakia. Common skin conditions that cause white patches, such as amelanotic nevi and pityriasis alba, will appear yellowish-white or grayish-white under Wood's lamp irradiation, while tinea versicolor will display a brownish-yellow or yellowish-white color. If the patient's white patches appear pure white with fluorescence and have a distinct boundary with the surrounding normal skin, it is necessary to consider vitiligo. Wood's lamp testing is accurate in diagnosing skin diseases, but it cannot completely confirm the diagnosis of leukoplakia alone. Other examination items are also needed to ensure the accuracy of the diagnosis.
There is no significant gender difference in the symptoms of vitiligo, and it can occur in all age groups, but it is more common in adolescents. Skin lesions are characterized by depigmentation patches, which are often milky white or light pink, smooth, and without rash. The boundary of the white patches is clear, and the pigment around the edges is increased compared to normal skin. The hair within the white patches may be normal or white. The lesions tend to occur in areas exposed to sunlight and friction, and the lesions are often symmetrically distributed. The white patches often arrange in bands according to the distribution of nerve segments. In addition to skin lesions, the lips, labia, glans penis, and inner mucosa of the foreskin can also be affected. Most patients do not have self-aware symptoms, but a few patients may experience local itching in the affected area before or at the same time as the onset of the disease. Vitiligo is often accompanied by other autoimmune diseases, such as diabetes, thyroid disease, adrenal insufficiency, scleroderma, atopic dermatitis, and alopecia areata.
