Freckles
Medical Author: Nili N. Alai, MD, FAAD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
Making Sense of Sunscreen Products
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor:
Barbara
K. Hecht, PhD
Most people are understandably confused when it comes to
choosing a sunscreen
because of the baffling array of available choices. Common questions about
sunscreens include
- How high should the SPF be?
- Should it block UVA or UVB?
- Does it matter whether it is a gel, cream, or spray?
- Should it be water-resistant or waterproof?
SPF stands for sun protection
factor.
The SPF numbers on a product can range from as low as 2 to as high as 60. These
numbers refer to the product's ability to screen or block out the sun's burning
rays. The SPF rating is calculated by comparing the amount of time needed to
produce sunburn on protected skin to
the amount of time needed to cause a sunburn on unprotected skin. The higher the
SPF, the greater the sun protection.
What are freckles?
Freckles are flat, tanned circular spots that typically are the size of the head of a common nail. The spots are multiple and may develop randomly on the skin, especially after repeated exposure to sunlight. These are particularly common in people of fair complexion on upper-body skin areas like the cheeks, nose, arms, and upper shoulders. They may appear
on people as young as age 1 or 2.
Most freckles on a person's skin are usually uniform in color. On different people, freckles may vary somewhat in color -- they may be reddish, yellow, tan, light brown, brown, or black -- but they are basically slightly darker than the surrounding skin. They tend to become darker and more apparent after sun exposure and lighten in the winter months. Freckles are due to an increase in the amount of dark pigment called melanin and are not due to an increase in the total number of pigment-producing cells called melanocytes. The word
freckle comes from the Middle English freken, which, in turn, came
from the Old Norse freknur, meaning "freckled." (Some speakers of Old English and Old Norse must have had a tendency to developing freckles.)
What types of freckles are there?
There are two basic types of freckles: simple freckles and sunburn freckles. Simple freckles are usually tan, round, and small -- about the size of a common construction nail head. Sunburn freckles are often darker, have irregular jagged borders, and may be larger than a pencil eraser. Sunburn freckles are more common on the upper back and shoulders where people frequently get their most severe sunburns.
Ephelides (singular: ephelis) is the Greek word and medical term for freckle. This term refers to flat spots that are tan, slightly reddish, or light brown and typically appear during the sunny months. They are most often found
on people with light complexions, and in some families, they are a hereditary (genetic) trait. People with reddish hair and green eyes are more prone to these types of freckles. Sun avoidance and sun protection, including the regular use of sunscreen, may help to suppress the appearance of the some types of freckles.
Lentigines (singular: lentigo) comes from the Latin word for lentil and is the
medical term for certain types of darker freckles and sunburn freckles. Lentigines tend to be darker than the common freckle and do not usually fade in the winter. This kind of spot is referred to as lentigo simplex. Although occasionally lentigines are part of a rare genetic syndrome, for the most part they are just isolated and unimportant spots.
Next: What are "liver spots" or "age spots"? »
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