Oregon Esthetician State Board

Under a Wood's lamp, how does a thick corneum layer appear?

1. Black

2. White fluorescent

3. Yellow

4. Red

The correct answer is: White fluorescent

Under a Wood's lamp, a thick corneum layer appears as white fluorescent. The Wood's lamp emits ultraviolet light that causes various skin conditions and characteristics to fluoresce differently. In the case of a thick stratum corneum, which is the outermost layer of the skin, it reflects this UV light and gives off a bright white appearance. This characteristic helps estheticians and dermatologists assess the skin's condition, allowing them to identify areas of excess keratinization or thickened skin that may require specific treatments or interventions. The other manifestations noted in the other options indicate different skin conditions or characteristics, which would be illuminated in different colors under the Wood's lamp. Understanding these visual cues is essential for proper skin analysis and treatment planning in esthetic practice.