What causes white spots on the arms and legs - Dermatologist's info.
I received a question from a reader about the white spots on her arms and legs. I though all my readers would find the topic of interest so I created this post.
Dear Dr. Bailey,
I love the information in your blogs. I have a question about white spots that are on my arms and legs. They don’t tan, are they a form of skin cancer?
Thank you, looking forward to reading more info on your blog,
The most common cause of white spots on the arms and legs of an adult are guttate hypomelanotic macules. This long name actually refers to a very simple condition - the flat little white skin spots that start showing up around middle age. The name sort of translates into 'discrete flat spots that are lighter in color than the surrounding skin'. Another name is idiopathic guttate hypomelanosis. The word "idiopathic" means that we don't know the cause!
When I see guttate hypomelanotic macules on someone's skin, I usually also see other evidence of sun damage such as flat brown sun spots that have no scale and that are called solar lentigines. These are age spots (sometimes referred to as "liver spots") that are actually sun freckles due to years of chronic sun exposure.
What are guttate hypomelanotic macules on the skin?
Guttate hypomelanotic macules are usually seen on the outside of the arms and the legs. They are smooth surfaced, slightly shiny and don’t itch or hurt. There is less pigment than normal in the first living skin layer called the epidermis. The top dead cell layer, called the stratum corneum, is a little thicker than normal but very compact, resulting in a slight shine if you look closely at the spots.
These little spots are entirely benign and don’t become cancer or anything other than a decorative nuisance. They don’t tan and they are still visible even when a person uses fake tanners. They are especially likely to be seen in people who have had a lot of sun exposure during their lifetime, leading us to believe that they are somehow a part of sun damage.
Are there any treatments for guttate hypomelanotic macules?
Doctors don’t know why people get these little spots and they are impossible to fix. They can’t be burned off, scraped off or lasered. I recommend that people try really hard to prevent them. The best way I have found to prevent or reduce the number of guttate hypomelanotic macules that your skin wants to make is to exfoliate really well. I use a combination of a physical exfoliation shower cloth or sponge followed by application of a professional strength glycolic acid moisturizer. The glycolic acid loosens the dead cells and the physical exfoliation helps them slough off. I've even seen this get rid of these persistent and annoying spots!
For years I have used this exfoliation combination in my practice. I've seen it slow the rate at which people collect guttate hypomelanotic macules. I watched it do the same on my own skin once I started developing them on my arms. The best product combination to achieve this double exfoliation are in my Ultra-Fast Triple Action Body Smoothing Kit.
It is also really important to protect skin from further sun damage. Wearing sun protective clothing when outdoors and/or using a broad spectrum zinc oxide sunscreen is recommended. One of the easiest good sunscreens to use on the arms and legs is Sheer Strength Pure Physical SPF 30 Water Resistant Broad Spectrum Sunscreen . Patients in my practice have proven for years that daily use of sunscreen helps reduce both white and brown spots on the arms and legs.
Another tip is to apply self-tanning lotion to the skin of the arms and legs. Oddly, the white spots may pick up the tanner more than your surrounding skin and this can help to make them less noticeable. Self-tanning lotions often contain heavy and harsh artificial fragrance because the tanning ingredient, called dihydroxyacetone, has a strong odor. My preference is Avene Self-Tanning Lotion because it has only a mild hypoallergenic fragrance. It also has a nice thin texture and can be applied under the Glycolic Acid Body Lotion in my Ultra-Fast Body Smoothing Kit.
Not seeing your white spots, I can’t be certain that you have guttate hypomelanotic macules. The information I’ve just given is inspired by your question, but you need to see your doctor for an exact diagnosis. There are other causes of white spots on the skin, some are common and some are rare, some have important health implications and others don’t.
Even though I can't guarantee that this information fits your specific situation, I hope you’ve found it interesting and helpful.
Cynthia Bailey MD, Dermatologist
Disclaimer: Please realize that availing yourself of the opportunity to submit and receive answers to your questions from Dr. Bailey does not confer a doctor/patient relationship with Dr. Bailey. The information provided by Dr. Bailey is general health information inspired by your question. It should not be a substitute for obtaining medical advice from your physician and is not intended to diagnose or treat any specific medical problem (and is not an extension of the care Dr. Bailey has provided in her office for existing patients of her practice). Never ignore your own doctor’s advice because of something you read here; this information is for general informational purpose only.