top of page
  • Writer's pictureTim Ionnides MD

4 Things Tim Ioannides MD Wants You to Know About Sun Damage

It feels good to be in the sunshine. Just look at how cats tend to find sun patches and lounge lazily in them for hours, enjoying the warmth and light it brings. Unfortunately, humans lack the protective layer of fur that animals have and for us too much sun exposure can significantly damage our skin. At best it is the cause of sunburn, wrinkles, age spots and scaly patches called actinic keratosis, and at its worst it leads to skin cancer. In fact, on average a person's risk for melanoma doubles if they have had more than five sunburns, but even just one blistering sunburn in childhood or adolescence more than doubles a person's chances of developing melanoma later in life. Skin cancer is no joke - one in five Americans will develop skin cancer by the age of 70, making it the most common type of cancer in the United States.

Tim Ioannides MD has been practicing dermatology for over twenty years on the Treasure Coast of Florida. Starting out his career in cosmetic dermatology, he soon found the work of elective procedures unfulfilling and left to form his own practice that would focus exclusively on the medical side of the specialty. He is also a volunteer associate professor at the University of Miami where he regularly assists in instruction on dermatologic and reconstructive surgery and was a senior author on two papers in the Journal of American Medical Association of Dermatology. Today with five practice locations in some of the counties with the highest skin cancer rates in the country, Dr. Ioannides has learned that the best way to help people prevent sun damage is by educating them as much as possible. Below are four key points that Dr. Ioannides wants everybody to know so that they can make informed decisions when it comes to preventing sun damage.

1. Know how the sun damages your skin

For Dr. Ioannides, the first step in preventing sun damage is knowing the science behind how it happens in the first place. Wrinkles, sagging skin and dark spots may seem like an inevitable part of getting older, but in actuality if we never saw any exposure to the sun we would never show these tell-tale signs of the aging process. The sun emits ultraviolet (UV) rays which damage our skin and the DNA within it when it is exposed. There are three types of UV rays, two of which are able to reach the Earth's surface: UVB rays and UVA rays.

UVB rays

UVB rays are the primary cause of skin discoloration and sunburn, which is actually your body having an inflammatory response to the UV rays damaging the DNA within its cells. To help with the healing process, it floods the damaged area with blood which results in both the red skin and painful inflammation characteristic of a sunburn.

UVA rays

UVA rays' longer wavelengths mean they penetrate deeper into the skin, damaging the elastin fibers within it and causing it to lose its elasticity, sag and stretch. With sustained damage, it will eventually cause the skin to bruise and tear more easily and heal at a much slower rate.

Sun damage to your skin can alter the DNA in its cells so that it can't properly control skin cell growth. The cells continue to grow but the old ones remain instead of dying off, resulting in an abnormal growth of skin tissue that we call a cancerous tumor. Although they affect your skin differently, both types of UV rays increase the risk of developing cancer when they come in contact with your skin.

2. Know the most common types of skin cancer

Rather than blatantly following rules set out for you, arming yourself with knowledge is one of the best ways you can remain vigilant about sun damage according to Dr. Ioannides. More than two people die of skin cancer in the United States every hour, but when detected early the survival rate for skin cancer is incredibly high. That is why it is imperative to know the most common types of cancer and their most familiar characteristics, although any noticeable change in your skin is grounds for a visit to a dermatologist.

Basal cell carcinoma

Basal cell carcinoma is the most common form of skin cancer in the world, and over four million cases are diagnosed every year in the United States alone. It is so named because it arises from abnormal, uncontrolled growth of basal cells which are found in the epidermis of the skin. While common, basal cell carcinoma tends to grow slowly and rarely spreads beyond the original tumor location, meaning that if they are caught and treated early most are curable and cause minimal damage. However, if left untreated they have the ability to grow wide and deep, destroying healthy tissue and bone around it. Additionally, the longer treatment is delayed the higher the recurrence rate. Basal cell carcinoma growths most often occur on parts of the body that see frequent exposure to the sun such as the face, scalp, ears, chest, arms, back, and legs. The most common form seen is a small dome-shaped bump with a pearly white color, but it can also appear as a blue, brown or black lesion with a slightly raised translucent border. About half of basal cell carcinomas in patients with darker skin are pigmented. It can also occur as a raised, scaly and reddened patch of skin or a pimple-like growth that heals and then reappears.

Squamous cell carcinoma

The second-most common form of skin cancer is squamous cell carcinoma. More than one million cases are diagnosed in the United States each year, and in the last 30 years cases have increased up to 200 percent. People who are middle-aged and elderly are most likely to be affected by this type of cancer, and the risk increases further if they have fair complexions and frequent exposure to the sun. This type of cancer is also located in the epidermis layer of the skin in the squamous cells, and like basal cell carcinoma can be prevented from spreading to other parts of the body so long as it is caught in a timely fashion. However, there are certain aggressive types of squamous cell carcinomas that can target the lymph nodes and other organs if left untreated. It is most likely to appear on sun-exposed areas of the body -- including your lips -- and can appear as open sores, scaly red patches, rough, thickened or wart-like skin, or raised growths with a central depression.

Malignant melanoma

While less common than the previous two types of skin cancer, malignant melanoma has the ability to spread to other organs at a more rapid pace, making it more deadly. Occurring in the melanocyte skin cells which produce pigment and give skin its color, only 20 to 30 percent of melanoma are found in existing moles, while 70 to 80 percent arise on normal-looking skin. There are four main types of melanoma of the skin: superficial spreading melanoma, lentigo maligna, acral lentiginous melanoma, and nodular melanoma. Superficial spreading melanoma is the most common form and nodular melanoma is the most aggressive. It can appear in a number of different sizes and colors which makes it difficult to provide a comprehensive set of warning signs, but acral lentiginous melanoma in particular is the most common form of melanoma found in people of color, including individuals of African ancestry, and it often appears in hard-to-spot places including under the nails and on the soles of the feet or palms of the hands.

3. Know how to practice sun avoidance

While sunscreen is a crucial step in the prevention of skin cancer, an even more effective method of prevention is to avoid getting sun damage in the first place. Tim Ioannides MD believes that not enough emphasis is placed on simple steps that can be taken in daily life to ensure that you are limiting your exposure to the sun, and therefore limiting the damage it can do to your skin.

Cover up

Unlike sunscreen which requires constant and consistent reapplication in order to be most effective, clothing provides an even and opaque coverage. In the winter (yes you can still get sun damage in the winter) it is easy enough to bundle up, but in the summer heat there have been continued advancements in fabric development that mean there are items on the market that provide both protection and breathability, known as UPF clothing. Additionally, a wide-brimmed hat and UV-blocking sunglasses provide relief for your skin from the sun's harsh rays.

Find the shade

It is an unrealistic expectation for everybody to completely cover their skin in clothing at all times, but by simply being aware of your surroundings you have the ability to prevent significant sun damage. It is important to note that the shade won't completely protect you from UV rays but it does make a difference in diffusing the sun's intense rays, so try to find the shade anytime you are outside, and especially when the sun is at its peak intensity between 10A and 4P. Choosing to walk on the shaded side of the street, using an umbrella or seeking out trees are all simple ways you can reduce your UV exposure.

Expect the unexpected

It is also important to remember that even if you are shielded from direct sunlight UV rays can still reach your skin indirectly such as by reflecting off of water, snow, sand or glass, or passing through the leaves and branches of trees. Even indoors your skin is still susceptible to sun damage, as glass can block UVB rays relatively well but still allows UVA rays to pass through. In cars, the front windshield is usually treated to protect drivers from the brunt of UVA rays, but the side, back and sunroof windows are now. You can have a UV-protective film applied to your home and untreated car windows, but also remember that trains and buses are likely left untreated, and airplane windows result in even more UV exposure because of the high altitude.

4. Know your SPF and sunscreen application.

Dr. Ioannides knows that expecting everybody to avoid sun exposure all day every day is an unrealistic expectation, which is why he recommends daily sunscreen usage. Together with sun avoidance, sunscreen has been proven to provide significant protection and prevention of skin cancer, with people who regularly use an SPF 15 or higher sunscreen daily reduce their risk of developing squamous cell carcinoma by about 40 percent, melanoma by 50 percent, and show 24 percent less skin aging than those who do not use sunscreen daily.


SPF stands for "sun protection factor" and rather than telling you how strong a sunscreen is, it indicates the multiplier by which you would compare how long the suns' UVB rays would take to redden your skin if you apply the sunscreen exactly as directed as compared with the amount of time without sunscreen. Put simply, if you apply a sunscreen product with an SPF of 30 correctly, you would burn 30 times quicker if you didn't use any sunscreen at all. SPF also does nothing to block UVA rays, so in order to be protected from both forms of UV radiation you need to seek out a sun protection product that has a UVA rating of four or five stars a well.


Going down the sunscreen aisle can be daunting with the dozens of different options available, but generally if your average day is mostly spent indoors, any product with an SPF of 15 should be adequate. However, if you will be spending a lot of time outdoors you should up your SPF accordingly.

Apply your sunscreen 30 minutes before being exposed to the sun, and about one shot glass worth should be enough to cover your entire body, equivalent to one ounce. After that, reapplication should occur at least every two hours, but even more often if you are in the water or sweating often.


bottom of page