A medical-grade Wood’s lamp is a diagnostic tool used by dermatologists and other healthcare professionals to examine the skin, hair, and scalp. It emits long-wave ultraviolet (UV) light, often called “black light,” which is invisible to the naked eye. The principle behind its use is that certain substances, such as bacteria, fungi, and pigments in the skin, will fluoresce (glow) or appear in distinct colors when exposed to this UV light. This allows for the identification of conditions that might not be visible under normal lighting.
Here’s how a medical-grade Wood’s lamp works for skin analysis and its benefits:
How it Works:
UV Light Emission: The Wood’s lamp contains a specialized filter (often made of barium silicate with nickel oxide) that blocks most visible light and allows only long-wave UV light (typically around 320-450 nm, with a peak at 365 nm) to pass through.
Fluorescence: When this UV light hits the skin, certain compounds (fluorophores) within the skin, or produced by microorganisms on the skin, absorb the UV energy and then re-emit it at a longer, visible wavelength. This re-emitted light is what the examiner sees as fluorescence.
Darkened Room: The examination is performed in a completely darkened room. This is crucial because it allows the subtle fluorescence to be clearly visible against the darkness, preventing interference from ambient light.
Interpretation of Colors: Different conditions cause different colors or appearances under the Wood’s lamp. A trained professional interprets these patterns to aid in diagnosis.
