Like a topical medicine, a topical reference or story applies to something specific, focusing on a topic that's currently in the news. TV comedians often use topical humor, making jokes about a currently popular movie or the latest political scandal—if possible, one that just broke that same day. Topical humor has a short lifespan, though, because the news keeps changing and the new hot topics just keep coming. The medical meaning of topical stays closer to the meaning of the root, since it describes something that's put right on the place that seems to need it.
Phototherapy or light treatment is an effective treatment for eczema. With phototherapy, various wavelengths of sunlight (UVB, UVA, combined UVA/UVB, UVA1, or narrow-band) are administered in a unit that is similar to a telephone booth but which is lined by fluorescent appearing light bulbs. The type of phototherapy that you will receive will be determined by your dermatologist. It is usually administered twice weekly. Possible side effects of phototherapy are redness, sunburn, or dryness. Long-term side effects, which are more likely with white skin, are possible skin cancers and enhanced aging.