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  • Writer's pictureTim Ionnides MD

Dermatologist Dr. Tim Ioannides’s Skin Cancer 101: The Most Common Types, What to Look Out for

... and How to Avoid Getting it in the First Place

As we move into the coldest months of the year, it can be easy to forget about the dangers of sun exposure when you’re feeling the chilly temperatures of winter. However, sun exposure can occur when and where you least expect it, and that includes on cloudy days and in the snow. Both in the United States and worldwide, skin cancer is the most common type of cancer, and more than two people die of skin cancer in the United States every hour. There is a one in five chance that you will develop skin cancer by the time you are 70, and yet despite these grim statistics there continues to be confusion and persistent myths regarding the subject. Thankfully, Florida dermatologist Dr. Tim Ioannides has made it his mission in life to not only treat skin cancer, but also aid in preventing it from occurring.

Ioannides was born and raised in Miami, where both his parents worked within the medical field. His mother was an eye technician, and his father was a renowned clinical professor in the pathology department of the University of Miami who also founded the university’s dermatopathology laboratory. Following in his father’s footsteps, Ioannides attended medical school and completed a dermatology residency, before he began his career at a plastic surgery practice. However, he soon found the work of elective cosmetic procedures unfulfilling, and made the decision to start his own practice that would focus exclusively on the medical side of dermatology. Initially basing his practice in St. Lucie County, Ioannides’ practice specialized in skin cancer, and he quickly learned that he had coincidentally started his practice in the county with the second-highest skin cancer rates in the United States.

After over twenty years, Ioannides’ practice has grown to five locations in three counties across the Treasure Coast of Florida. He is able to perform the specialized, highly effective Mohs micrographic surgery for skin cancer removal, which has the highest reported cure rate while also resulting in much less scarring. In addition to his practice, Dr. Ioannides 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. The paper’s subject was on the role of the HPV vaccine in treating skin cancer, and it earned one of the “Most Talked About” honors from the publication in 2018. As an educator at heart, Ioannides’ wish is that everybody be as informed on the facts of skin cancer as possible and below we explore a crash course on the subject.


Contrary to popular belief, much of what is considered part of the normal aging process — dark spots, wrinkles, sagging skin — is actually a result of the skin’s exposure to the sun. The sun emits ultraviolet (UV) rays, and while there are three types of UV rays only two are able to reach the earth’s surface: UVA and UVB.

UVA rays have the longer wavelengths of the two, and therefore penetrate deeper in the skin, damaging the fibers in the skin called elastin. This is what causes it to lose its elasticity and sag and stretch over time as it also begins to take longer to heal, bruising and tearing more easily.

UVB rays are the primary cause of skin reddening and sunburn, which is your body’s reaction to damage to the DNA in 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.

Damage to your skin can alter the DNA in its cells so that it can’t properly control skin cell growth, leading to an abnormal growth of skin tissue that we call a cancerous tumor. Although they have different effects, both UV rays increase the risk of developing cancer when they come in contact with your skin.


Basal Cell Carcinoma: The most common form of skin cancer in the world, over 4 million cases of basal cell carcinoma are diagnosed in the United States each year. It arises from abnormal, uncontrolled growth of basal cells, which are located in the outermost layer of the skin known as the epidermis and produce new skin cells as old ones die. Basal cell carcinoma has a tendency toward slow growth and rarely spread beyond the original site of the tumor, so if they are caught and treated early most are curable and cause minimal damage. However, if they are allowed to grow the cancerous skin tissue (sometimes called lesions) can grow wide and deep, destroying healthy tissue as well as bone in the surrounding area, and delays in treatment also result in a higher 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: After basal cell carcinoma, the most common form of skin cancer is squamous cell carcinoma with more than one million cases diagnosed in the United States each year. Also located in the epidermis, squamous cells are thin and flat, fitting closely together in tissues to provide a smooth, low-friction surface over which fluids can move easily. Like basal cell carcinoma, squamous cell carcinoma can be prevented from spreading to other parts of the body so long as it is caught in a timely fashion, but 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. Middle-aged and elderly people are most likely to be affected by this type of cancer, with a further increased risk if they are frequently exposed to the sun and have fair complexions. In the last thirty years, squamous cell carcinoma has increased up to 200 percent.

Malignant Melanoma: Although melanoma is less common than basal cell carcinoma and squamous cell carcinoma, it is also more deadly due to its ability to spread to other organs at a more rapid pace. If you’ve ever taken a high school level biology class, you may remember that melanin is the pigment that gives the skin its color, and melanomas occur in the uncontrolled growth of the melanocyte skin cells that produce that pigment. 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. Only 20 to 30 percent of melanoma are found in existing moles, while 70 to 80 percent arise on normal-looking skin.

It is important to note that while some forms of skin cancer have common characteristics, it can look quite different from one person to another, so vigilance is needed to identify any new growths or irregularities of the skin.


So, we know how skin cancer occurs and the most common types to look out for; how do we avoid getting it in the first place? While wearing sunscreen when outdoors is crucial to the prevention of skin cancer (we’ll cover the topic in detail shortly) the preventative measure is to avoid getting sun damage in the first place. Clothing in many ways can be considered more effective than sunscreen at providing a barrier from UV rays because of the consistency of its coverage and the fact that it doesn’t require constant reapplication. While it is easy enough to bundle up in the winter, the summer heat can prove tricky. Luckily, there have been continued advancements that have seen the development of fabrics that provide both protection and breathability, and accessories such as a wide-brimmed hat and UV-blocking sunglasses can also be effective solutions.

Expecting everybody to walk around in turtlenecks all day everyday simply isn’t realistic, so being aware of your surroundings is another important factor in sun avoidance. While the shade won’t completely protect you from UV rays it does make a difference, so seek out the shade on sunny days, especially between the hours of 10A and 4P when the sun is most intense. Some easy ways to achieve this would be walking on the shaded side of the street, using an umbrella, or under trees. However, don’t forget that UV rays can still reach your skin through indirect sources, such as reflecting off of water, snow, sand, or glass, or passing through leaves and branches of trees.

Unfortunately, even in the comfort of your own home or car your skin is still susceptible to sun damage. Glass has the ability to block UVB rays relatively well, but the longer UVA rays are still able to pass through. Car manufacturers usually treat the front windshield to protect drivers from most UVA rays, but don’t do so for the side, back and sunroof. In your home and car you can have a UV-protective film applied to the windows, but it is still important to remain aware of UV exposure from the windows of airplanes, trains, and buses.

While UV radiation from the sun accounts for 90 percent of nonmelanoma skin cancers, indoor tanning devices have the ability to emit it at levels 10 to 15 times higher than the sun at its peak intensity. In fact, indoor tanning even one time immediately results in an 83 percent increased risk of developing squamous cell carcinoma and a 29 percent increased risk of developing basal cell carcinoma, and using a tanning bed before age 35 increases your risk of melanoma by 75 percent. To put the risk of indoor tanning further into perspective: more people develop skin cancer because of indoor tanning than develop lung cancer because of smoking.


The fact of the matter is, it would be impossible to completely avoid direct sun exposure to your skin 100 percent of the time. This is where sunscreen comes into play. 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.

Sunscreen works by either blocking or absorbing the UV rays before they can penetrate your skin. “Physical” sunscreens containing zinc oxide and titanium dioxide reflect UV radiation from the skin, while “chemical” sunscreens use active ingredients such as avobenzone, octinoxate and oxybenzone to absorb the rays and release the energy as heat. It is a common misconception that physical sunscreens are more “natural” or even “organic,” as the active ingredients for both types of sunscreen are chemically derived, and both are equally effective when applied properly.

So, what is proper application? This comes down to a number of factors. The first is the SPF rating, which stands for “sun protection factor.” Rather than simply telling you how strong a sunscreen is, the SPF number actually indicates the multiplier by which you would compare how long the sun’s UVB rays would take to redden your skin if you apply the sunscreen exactly as directed compared with the amount of time without sunscreen. This means that using an SPF 15 product correctly, if you didn’t use any sunscreen you would burn 15 times quicker. You’ll also notice that SPF is what blocks UVB rays, but on its own it doesn’t protect your skin from UVA rays which we learned earlier can also increase your likelihood of developing skin cancer. That is measured by a sun protection product’s UVA rating, which should preferably have four or five stars.

If your average day is mostly spent indoors, any product with an SPF of 15 should be adequate, but if you are going to be spending a lot of time outdoors a higher SPF is likely necessary.. The general rule for sunscreen application is that one ounce (a shot glass worth) of sunscreen should be enough to cover your entire body. It should be applied 30 minutes before being exposed to the sun, and then reapplied at least every two hours — even more often if you will likely be in the water or perspiring frequently, and in those cases it is also advisable to use a water-resistant sunscreen. Note that the term is water-resistant: no sunscreen product can claim to be completely waterproof


So there you have it, the basic facts and knowledge behind skin cancer. In reading this information, it should be clear to you that the best steps toward staying safe are remaining aware of the potential ways the sun can be damaging your skin at any given time and staying vigilant in noticing changes to the skin on all parts of your body. The Skin Cancer Foundation recommends that you perform a comprehensive scan of your body once a month, including places like behind your ears and between your toes, and having anything new, changing, or unusual immediately checked by a dermatologist.


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