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Photoprotection is protection from light or the sun. The word "photo" meaning "light" and the word "protection" meaning "to defend against".
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Do people who have xeroderma pigmentosum go to school?
Xeroderma pigmentosum (XP) is heterogenic disease.XP variant need a minimum of photoprotection it can be considered as normal people.XPA has a neurologic abnormalities, some are severe and can't be succeful in the school. Mild form can study and learn some technique home work.XPC are intelligent but need a high photoprotection
What other pigments exist in green leaves and what is their functions?
Carotenoids can be found in green leaves which are hydrocarbons that are multiple shades of yellow and orange. Some carotenoids function as photoprotection, they absorb and dissipate excessive light energy that would otherwise harm the chlorophyll.
How do melanin carotene and blood affect skin color?
Melanin darkens skin. It is also responsible for photoprotection, ie resistance to ultraviolet light-induced skin damage. This is achieved by rapidly converting incoming ultraviolet light into heat, which is much less likely to cause problems like free radicals. Thus, sunlight exposure tends to stimulate melanin production.
What is the difference of melanocytes and keratinocytes?
Answer taken from the article:Costin & Hearing (2007). Human skin pigmentation: Melanocytes modulate skin color in response to stress. The Faseb Journal, 21(4), 976-994."Melanin biosynthesis is a complex pathway that appears in highly specialized cells, called melanocytes, within membrane-bound organelles referred to as melanosomes. Melanosomes are transferred via dendrites to surrounding keratinocytes, where they play a critical role in photoprotection. The anatomical relationship between keratinocytes and melanocytes is known as 'the epidermal melanin unit' and it has been estimated that each melanocyte is in contact with ∼40 keratinocytes in the basal and suprabasal layers."Translated: Melanocytes produce melanin in nice little packages called, melanosomes. These melanosomes are then transferred to neighboring keratinocytes (i.e., the hair follicle) through dendrites. This is how the hair follicle gets its color, even though the actual hair follicle doesn't produce melanin itself.
Why do leaves change in color?
Inside the leaf there are millions of tiny discs filled with a green pigment called chlorophyll. These green 'packages' are used to trap sunlight which is used as an energy source to produce glucose (a type of sugar) in a process called photosynthesis.There are other packages that are coloured in yellow (xanthrophyll) and some in orange (carotene), which are used in other processes in the leaf.During the summer (in the presence of sunlight and plenty of water photosynthesis can take place) and the green packages are very active, so they hide away (or mask) the yellow and orange ones.As fall approaches the weather grows colder and the hours of sunshine shrink as well. The trees 'realise' that winter is approaching and so they begin to prepare for it. Layers of cells grow over the tubes that carry water and glucose closing them up and making photosynthesis impossible (which requires water and sunlight).The green chlorophyll starts to break down and disappear, and so the colours of the other 'packages' can be seen, the yellow xanthrophyll and the orange carotene. As the tubes that carry glucose are trapped as well, sugar remains in the leaves, which with time (due to sunshine and cold) give the leaves a red or purple colour. As the leaves no longer have water and glucose flowing around, they slowly die, turning into brown (chlorophyll dies first, then xanthrophyll and carotene).A:Deciduous plants are believed to shed their leaves in autumn primarily because the high costs involved in their maintenance would outweigh the benefits from photosynthesis during the winter period of low light availability and cold temperatures.[1] However, there is no reason why leaf fall should necessarily be preceded by the production of vivid autumn colors, and the function of the color change is still uncertain. Autumn colors (especially red) are not just due to the breakdown of chlorophyll; in fact anthocyanins (red-purple) are actively produced in autumn. What use is the production of pigments in leaves that are about to fall? A number of hypotheses have been proposed, including photoprotection, coevolution and allelopathy:PhotoprotectionAccording to the photoprotection theory, anthocyanins protects the leaf against the harmful effects of light at low temperatures[2][3]. It is true that the leaves are about to fall and therefore it is not of extreme importance for the tree to protect them. Photo-oxidation and photo-inhibition, however, especially at low temperatures, make the process of reabsorbing nutrients less efficient. By shielding the leaf with anthocyanins, according to the photoprotection theory, the tree manages to reabsorb nutrients (especially nitrogen) more efficiently.CoevolutionAccording to the coevolution theory [4], the colors are warning signals towards insects that use the trees as a host for the winter, for example aphids. If the colors are linked to the amount of chemical defenses against insects, then the insects will avoid red leaves and increase their fitness; at the same time trees with red leaves will have an advantage because they reduce their parasite load. The coevolution theory of autumn colors was born as a branch of evolutionary signalling theory. It is a general feature of biological signals that, when a signal is costly to produce, it is usually honest - that is it reveals the true quality of the signaller, because it does not pay for a low quality individual to cheat. Autumn colors might be a signal if they are costly to produce, or they could be an index, which is maintained because it is impossible to fake (because the autumn pigments are produced by the same biochemical pathway that produces the chemical defenses against the insects). Although it is not certain that aphids have red receptors, there is some evidence that they preferentially avoid trees with red leaves. This is what the coevolution theory predicts at the intraspecific level (more insects on dull leaves). It is also known that tree species with bright leaves have more specialist aphid pests than do trees lacking bright leaves[5], which is the interspecific prediction of the theory (autumn colors are useful only in those species coevolving with insect pests in autumn). The coevolution hypothesis has been subjected to criticism.[6]The change of leaf colors prior to fall have also been suggested as adaptations that may help to undermine the camouflage of herbivores.[7]Many plants with berries attract birds with especially visible berry and/or leaf color, particularly bright red. The birds get a meal while the shrub, vine or typically small tree gets undigested seeds carried off and deposited with the birds' manure. Poison Ivy is particularly notable for having bright red foliage drawing birds to its off-white seeds (which are edible for birds, but not most mammals).AllelopathyResearchers at New York's Colgate University have found evidence that the brilliant red colors of maple leaves is created by a separate processes then those in chlorophyll breakdown. At the very time when the tree is struggling to cope with the energy demands of a changing and challenging season maple trees are involved in an additional metabolic expenditure to create anthocyanins. These anthocyanins, which create the visual red hues, have been found to aid in interspecific competition by stunting the growth of nearby saplings in what is known as allelopathy. (Frey & Eldridge, 2005)
Why do tree leaves turn colors in the fall?
Inside the leaf there are millions of tiny discs filled with a green pigment called chlorophyll. These green 'packages' are used to trap sunlight which is used as an energy source to produce glucose (a type of sugar) in a process called photosynthesis.There are other packages that are coloured in yellow (xanthrophyll) and some in orange (carotene), which are used in other processes in the leaf.During the summer (in the presence of sunlight and plenty of water photosynthesis can take place) and the green packages are very active, so they hide away (or mask) the yellow and orange ones.As fall approaches the weather grows colder and the hours of sunshine shrink as well. The trees 'realise' that winter is approaching and so they begin to prepare for it. Layers of cells grow over the tubes that carry water and glucose closing them up and making photosynthesis impossible (which requires water and sunlight).The green chlorophyll starts to break down and disappear, and so the colours of the other 'packages' can be seen, the yellow xanthrophyll and the orange carotene. As the tubes that carry glucose are trapped as well, sugar remains in the leaves, which with time (due to sunshine and cold) give the leaves a red or purple colour. As the leaves no longer have water and glucose flowing around, they slowly die, turning into brown (chlorophyll dies first, then xanthrophyll and carotene).A:Deciduous plants are believed to shed their leaves in autumn primarily because the high costs involved in their maintenance would outweigh the benefits from photosynthesis during the winter period of low light availability and cold temperatures.[1] However, there is no reason why leaf fall should necessarily be preceded by the production of vivid autumn colors, and the function of the color change is still uncertain. Autumn colors (especially red) are not just due to the breakdown of chlorophyll; in fact anthocyanins (red-purple) are actively produced in autumn. What use is the production of pigments in leaves that are about to fall? A number of hypotheses have been proposed, including photoprotection, coevolution and allelopathy:PhotoprotectionAccording to the photoprotection theory, anthocyanins protects the leaf against the harmful effects of light at low temperatures[2][3]. It is true that the leaves are about to fall and therefore it is not of extreme importance for the tree to protect them. Photo-oxidation and photo-inhibition, however, especially at low temperatures, make the process of reabsorbing nutrients less efficient. By shielding the leaf with anthocyanins, according to the photoprotection theory, the tree manages to reabsorb nutrients (especially nitrogen) more efficiently.CoevolutionAccording to the coevolution theory [4], the colors are warning signals towards insects that use the trees as a host for the winter, for example aphids. If the colors are linked to the amount of chemical defenses against insects, then the insects will avoid red leaves and increase their fitness; at the same time trees with red leaves will have an advantage because they reduce their parasite load. The coevolution theory of autumn colors was born as a branch of evolutionary signalling theory. It is a general feature of biological signals that, when a signal is costly to produce, it is usually honest - that is it reveals the true quality of the signaller, because it does not pay for a low quality individual to cheat. Autumn colors might be a signal if they are costly to produce, or they could be an index, which is maintained because it is impossible to fake (because the autumn pigments are produced by the same biochemical pathway that produces the chemical defenses against the insects). Although it is not certain that aphids have red receptors, there is some evidence that they preferentially avoid trees with red leaves. This is what the coevolution theory predicts at the intraspecific level (more insects on dull leaves). It is also known that tree species with bright leaves have more specialist aphid pests than do trees lacking bright leaves[5], which is the interspecific prediction of the theory (autumn colors are useful only in those species coevolving with insect pests in autumn). The coevolution hypothesis has been subjected to criticism.[6]The change of leaf colors prior to fall have also been suggested as adaptations that may help to undermine the camouflage of herbivores.[7]Many plants with berries attract birds with especially visible berry and/or leaf color, particularly bright red. The birds get a meal while the shrub, vine or typically small tree gets undigested seeds carried off and deposited with the birds' manure. Poison Ivy is particularly notable for having bright red foliage drawing birds to its off-white seeds (which are edible for birds, but not most mammals).AllelopathyResearchers at New York's Colgate University have found evidence that the brilliant red colors of maple leaves is created by a separate processes then those in chlorophyll breakdown. At the very time when the tree is struggling to cope with the energy demands of a changing and challenging season maple trees are involved in an additional metabolic expenditure to create anthocyanins. These anthocyanins, which create the visual red hues, have been found to aid in interspecific competition by stunting the growth of nearby saplings in what is known as allelopathy. (Frey & Eldridge, 2005)
Why are there so many red haired people in Ireland?
Less than 10% are. In the UK red hair is generally associated with people of Celtic descent, i.e Scotland and Ireland. It is believed the people of Scotland came from 5 different ethnic groups who occupied or invaded northern Britain in the dark ages. In all of recorded history, red-haired people have never been mentioned as a group except by the Romans. The 'Picts' where foes who the Romans fought and were described as having red-hair and 'large limbs' by Roman historian Tacitus. Modern historians with the help of anthropologists have placed red-hair as a unique characteristic belonging to the Picts, who were characteristic to what is now regarded as Scottish. As far as the world-wide distribution of red-hair is concerned, it would be fair to say that the majority may well have descended from this North-Western European region, although as with all variations between people, mutations in genes can occur and be maintained in any population provided there is no detrimentus effect to the populations growth. As for the reasons for red-hair, it's not easy to see any immediate selective advantage in terms of evolution. Here is some information of the genetics behind red-hair and this seems to provide a clue.... Variation in both skin and hair pigmentation is due to varied amounts of the chemicals eumelanin (brown/black melanins) and phaeomelanin (red/yellow melanins) produced by melanocytes ("colour-cells"). The melanocortin-1 receptor (MC1R) is a regulator of eu- and phaeomelanin production in the melanocytes and mutations in this gene are known to cause coat colour changes in many mammals. Studies on Irish and Dutch populations have significantly linked variations in the MC1R gene to red-hair. Also, so called 'loss-of-function' mutations in the human MC1R gene are known to be common and have recently been shown to be associated with red-hair. One other interesting point is that recent work has shown that some variants on the MC1R gene may be preferentially associated with hair colour rather than skin type. Because the primary function of melanins is thought to be for both 'photoprotection' and 'photosensitising` (eu- and phaeomelanins respectively), this offers reason to suggest that MC1R variants (most red-heads) are a risk factor, possibly independent of skin type, for melanoma susceptibility. Why would mutations occur if such variations in MC1R originally arose in areas of northern-Europe. Maybe it was because there was no selection against such mutations occurring in that region of the world. Due to the poor quality of weather in this area of the world, any mutations in MC1R would hold no relevance as the UV-levels would be significantly low enough to cause no damage despite decreased melatonin protection. Unfortunately this assumes that MC1R mutations occurring in 'hot-climates' would result in high mortality rates occurring before age of parenthood which is probably unlikely. Other than that, I can't think of any other reason to suggest why red-hair originated in north-west Europe other than by random chance
Sun protection?
Avoiding the Sun and UV raysThe best way to lower your risk of skin cancer is to protect your skin from the sun and ultraviolet (UV) light.Using sunscreen and avoiding the sun help reduce the chance of many aging skin changes, including some skin cancers.However, it is important not to rely too much on sunscreen alone. You should also not use sunscreen as a reason to increase the amount of time you spend in the sun. Sunscreens do appear to protect against melanoma, though the evidence they protect against other types of skin cancer is not as strong.Even with the use of sunscreens, people should not stay out too long during peak sunlight hours. Even if you do not sunburn, UVA [ultraviolet A (long-wave)] rays can still penetrate your skin and do harm.The best way to prevent skin damage is to avoid excessive sun exposure:Avoid sun exposure, particularly during the hours of 10 a.m. to 4 p.m., when UV rays are the strongest.The dangers are greater the closer to the start of summer.Use sun protection, even on cloudy days. Clouds and haze do not protect you from the sun, and in some cases may intensify UVB [ultraviolet B (shortwave) rays.Avoid surfaces that reflect light, such as water, sand, concrete, snow, and white-painted areas.Skin burns faster at higher altitudes.Avoid sun lamps, tanning beds, and tanning salons. The machines use mostly high-output UVA rays.Sun-protective ClothingWear protective clothing and a hat to shield your face from the sun's rays.You can also buy sun protection factor (SPF) clothing and swimwear that block out UV rays. This clothing is rated using SPF (as used with sunscreen) or a system called the ultraviolet protection factor (UPF) index. The clothing is expensive, however.Everyone, including children, should wear hats with wide brims.Look for loose-fitting, unbleached, tightly woven fabrics. The tighter the weave, the more protective the garment.Washing clothes over and over improves UPF. An easy way to assess protection is simply to hold the garment up to a window or lamp and see how much light comes through. The less light the better.Everyone over age 1 should wear sunglasses that block all UVA and UVB rays when in the sun.Sunscreen GuidelinesUse sunscreens that block out both UVA and UVB radiation. Look for products that contain either zinc oxide or titanium oxide.Less expensive products that have the same ingredients work as well as expensive ones.Older children and adults (even those with darker skin) benefit from using SPFs of 15 and over.Some experts recommend that most people should use SPF 30 or higher on the face and 15 or higher on the body.Adults who burn easily and anyone with risk factors for skin cancer should use SPF 50+.When to use sunscreen:Adults should wear sunscreen every day, even if they go outdoors for only a short time.Apply 30 minutes before going outdoors for best results. This allows time for the sunscreen to be absorbed.Remember to use sunscreen during the winter when snow and sun are both present.Reapply at least every 2 hours while you are out in the sunlight.Reapply after swimming or sweating. Waterproof formulas last for about 40 minutes in the water, whereas water-resistant formulas last half as long.How to apply:Apply a large amount to all exposed areas. Pay close attention to your face, nose, ears, and shoulders. Do not forget your feet.Use half a teaspoon each for the head, neck, and each arm and a teaspoon each for the chest area, back, and each leg.Use a lip balm with sunscreen.Apply generous amounts of sunscreen with a SPF of at least 30. The higher the SPF, the greater the protection.Choosing the best sunscreen:Choose a waterproof or water-resistant formula, even if your activities don't include swimming.Avoid products that combine sunscreen and insect repellant. They may not work as well. Also, sunscreen should be re-applied often, while insect repellant applied too often could be toxic.Sun Protection and ChildrenSunscreens are safe in most toddlers and children, but they should not be the first and only lines of defense.All young children should be well-covered with clothing, sunglasses, and hats. Children should be kept out of the sun during peak sunlight periods.Do not use sunscreens on babies younger than 6 months without consulting a doctor.ReferencesGreen AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. J Clin Oncol. 2011;29(3):257-263.Lautenschlager S, Wulf HC, Pittelkow MR. Photoprotection. The Lancet [early online publication]. May 3, 2007.Hexsel CL, Bangert SD, Hebert AA, et al. Current sunscreen issues: 2007 Food and Drug Administration sunscreen labeling recommendations and combination sunscreen/insect repellant products. J Am Acad Dermatol. 2008;59:316-323.Reviewed ByReview Date: 08/21/2011David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Squamous cell skin cancer?
DefinitionSquamous cell skin cancer is a type of tumor that affects the skin.Alternative NamesCancer - skin - squamous cell; Skin cancer - squamous cell; Nonmelanoma skin cancer - squamous cell; NMSC - squamous cellCauses, incidence, and risk factorsSquamous cell cancer occurs when cells in the skin start to change. The changes may begin in normal skin or in skin that has been injured or inflamed. Most skin cancers occur on skin that is regularly exposed to sunlight or other ultraviolet radiation. Skin cancer is most often seen in people over age 50.Squamous cell carcinoma in situ (also called Bowen's disease) is the earliest form of squamous cell cancer. The cancer has not yet invaded surrounding tissue. It appears as large reddish patches (often larger than 1 inch) that are scaly and crusted.Actinic keratosis is a precancerous skin lesion. In rare cases it may become a squamous cell cancer.Risks for squamous cell skin cancer include:Having light-colored skin, blue or green eyes, or blond or red hairLong-term, daily sun exposure (such as in people who work outside)Many severe sunburns early in lifeOlder ageA large number of x-raysArsenicChemical exposureSquamous cell cancer spreads faster than basal cell cancer, but still may be relatively slow-growing. Rarely, it can spread (metastasize) to other locations, including internal organs.SymptomsThe main symptom of squamous cell skin cancer is a growing bump that may have a rough, scaly surface and flat reddish patches.The bump is usually located on the face, ears, neck, hands, or arms, but may occur on other areas.A sore that does not heal can be a sign of squamous cell cancer. Any change in an existing wart, mole, or other skin lesion could be a sign of skin cancer.Signs and testsYour doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas.If skin cancer is a possibility, a piece of skin will be removed from the area and examined under a microscope. This is called a skin biopsy. A biopsy must be done to confirm the diagnosis of basal cell carcinoma or other skin cancers.There are many types of skin biopsies. The exact procedure depends on the location of the suspected skin cancer.TreatmentSee also: Actinic keratosis for treatment informationSkin cancer has a high cure rate if it is treated early. Treatment depends on how big the tumor is, its location, and how far it has spread (metastasis).Excision refers to cutting out the tumor and using stitches to place the skin back together.Curettage and electrodesiccation scrapes away the cancer and uses electricity to kill any remaining cancer cells. It is used to treat cancers that are not very large or deep.Mohs surgery involves cutting out a layer of the skin cancer and immediately looking at it under a microscope to check if any cancer has been left behind. More layers are removed until the skin sample is free of cancer. Mohs surgery is more likely to be used for skin cancers on the nose, ears, and other areas of the face.Cryosurgery freezes and kills the cancer cells.Radiation may be used if the cancer has spread to organs or lymph nodes, or for squamous cell cancers that cannot be treated with surgery.Skin creams and the medications imiquimod or 5-fluorouracil may be used to treat actinic keratosis and superficial (not very deep) squamous cell carcinoma.Photodynamic therapy, a special type of light treatment, may be used to treat Bowen's disease (BD).Expectations (prognosis)Most (95%) of squamous cell tumors can be cured if they are removed promptly. New tumors may develop, however. If you have had squamous cell cancer, have your skin regularly examined by your health care provider.The outlook depends on a number of factors, including the type of cancer and how quickly it was diagnosed. Squamous cell carcinoma only rarely spreads to other parts of the body.Some squamous cell skin cancers may be more difficult to treat or can spread. This risk may depend on:The size or shape of the cancerWhat the cancer appears like when biopsy results are examined under a microscopeWhere the skin cancer is locatedYour other health problemsComplicationsLocal spread of the tumorSpread to other locations, including the internal organsCalling your health care providerCall for an appointment with your health care provider if you see the sore change in:AppearanceColorSizeTextureAlso call if you have pain, inflammation, bleeding, or itching of an existing skin sore.PreventionReduce your sun exposure. Protect your skin from the sun by wearing hats, long-sleeved shirts, long skirts, or pants.Sunlight is most intense between 10 a.m. and 4 p.m., so try to limit exposure during these hours.Use high-quality sunscreens, preferably with sun protection factor (SPF) ratings of at least 30 that protect against both UVA and UVB sunlight. Apply the sunscreen at least 30 minutes before going outside and reapply frequently. Use a sunscreen throughout the year, even during the winter. Use a waterproof formula.Other important facts to help avoid too much sun exposure:Avoid surfaces that reflect light, such as water, sand, concrete, and white-painted areas.The dangers are greater closer to the start of summer.Skin burns faster at higher altitudes.Avoid sun lamps, tanning beds, and tanning salons.Examine the skinregularly for any new suspicious growths or changes in an existing skin sore. A new growth that forms an ulcer or is slow to heal is suspicious.Suspicious changes in an existing growth include:A change in color, size, texture, or appearanceDevelopment of pain, inflammation, bleeding, or itchingReferencesAmerican Cancer Society. Cancer Facts and Figures 2006.Atlanta, GA: American Cancer Society; 2006.Basal cell and squamous cell cancers: NCCN Medical Practice Guidelines and Oncology:V.1.2009. Accessed July 15, 2009.Hexsel CL, Bangert SD, Hebert AA, et al. Current sunscreen issues: 2007 Food and Drug Administration sunscreen labeling recommendations and combination sunscreen/insect repellant products. J Am Acad Dermatol. 2008;59:316-323.Lautenschlager S, Wulf HC, Pittelkow MR. Photoprotection. The Lancet [Early online publication], May 3, 2007.Ridky TW. Nonmelanoma skin cancer. J Am Acad Dermatol. 2007;57:484-501.Wood GS, Gunkel J, Stewart D, et al. Nonmelanoma skin cancers: basal and squamous cell carcinomas. In: Abeloff MD, Armitage JO, Nierderhuber JE, Kastan MB, McKenna WG, eds. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa: Churchill Livingstone;2008:chap 74.
Squamous cell carcinoma?
I'll start by breaking down the terminology. Carcinoma is a cancer derived from epithelial cells, which are the lining cells that make up the skin, lining of the gastrointestinal tract, lining of the respiratory tract, etc. Squamous cell is a particular type of epithelial cell that is flat; there are only certain places in the body that have this type of epithelial cell. Well differentiated means the cells, while cancerous, are still typical in shape, size and intracellular characteristics for the type of cell they developed from. Putting everything back together, this is a cancer derived from the cells of either the skin or a body cavity lining that is still fairly normal appearing. Interpreting this, I would guess the cancer is associated with the skin and that the cancer is not likely to have metastasized yet.
Basal cell carcinoma?
DefinitionBasal cell carcinoma is a slow-growing form of skin cancer.See also:Squamous cell skin cancerMelanomaAlternative NamesRodent ulcer; Skin cancer - basal cell; Cancer - skin - basal cellCauses, incidence, and risk factorsSkin cancer is divided into two major groups: nonmelanoma and melanoma. Basal cell carcinoma is a type of nonmelanoma skin cancer, and is the most common form of cancer in the United States. According to the American Cancer Society, 75% of all skin cancers are basal cell carcinomas.Basal cell carcinoma starts in the top layer of the skin called the epidermis. It grows slowly and is painless. A new skin growth that bleeds easily or does not heal well may suggest basal cell carcinoma. The majority of these cancers occur on areas of skin that are regularly exposed to sunlight or other ultraviolet radiation. They may also appear on the scalp. Basal cell skin cancer used to be more common in people over age 40, but is now often diagnosed in younger people.Your risk for basal cell skin cancer is higher if you have:Light-colored skinBlue or green eyesBlond or red hairOverexposure to x-rays or other forms of radiationBasal cell skin cancer almost never spreads. But, if left untreated, it may grow into surrounding areas and nearby tissues and bone.SymptomsBasal cell carcinoma may look only slightly different than normal skin. The cancer may appear as skin bump or growth that is:Pearly or waxyWhite or light pinkFlesh-colored or brownIn some cases the skin may be just slightly raised or even flat.You may have:A skin sore that bleeds easilyA sore that does not healOozing or crusting spots in a soreAppearance of a scar-like sore without having injured the areaIrregular blood vessels in or around the spotA sore with a depressed (sunken) area in the middleSigns and testsYour doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas.If skin cancer is a possibility, a piece of skin will be removed from the area and examined under a microscope. This is called a skin biopsy. This must be done to confirm the diagnosis of basal cell carcinoma or other skin cancers. There are many types of skin biopsies. The exact procedure depends on the location of the suspected skin cancer.TreatmentTreatment varies depending on the size, depth, and location of the basal cell cancer. It will be removed using one of the following procedures:Excision cuts the tumor out and uses stitches to place the skin back together.Curettage and electrodesiccation scrapes away the cancer and uses electricity to kill any remaining cancer cells.Surgery, including Mohs surgery, in which skin is cut out and immediately looked at under a microscope to check for cancer. The process is repeated until the skin sample is free of cancer.Cryosurgeryfreezes and kills the cancer cells.Radiation may be used if the cancer has spread to organs or lymph nodes or for tumors that can't be treated with surgery.Skin creams with the medications imiquimod or 5-fluorouracil may be used to treat superficial basal cell carcinoma.Expectations (prognosis)The rate of basal cell skin cancer returning is about 1% with Mohs surgery, and up to 10% for other forms of treatment. Smaller basal cell carcinomas are less likely to come back than larger ones. Basal cell carcinoma rarely spreads to other parts of the body.You should follow-up with your doctor as recommended and regularly examine your skin once a month, using a mirror to check hard-to-see places. Call your doctor if you notice any suspicious skin changes.ComplicationsUntreated, basal cell cancer can spread to nearby tissues or structures, causing damage. This is most worrisome around the nose, eyes, and ears.Calling your health care providerCall your health care provider if you notice any changes in the color, size, texture, or appearance of any area of skin. You should also call if an existing spot becomes painful or swollen, or if it starts to bleed or itch.PreventionThe best way to prevent skin cancer is to reduce your exposure to sunlight. Ultraviolet light is most intense at midday, so try to avoid sun exposure during these hours. Protect the skin by wearing hats, long-sleeved shirts, long skirts, or pants.Always use sunscreen:Apply high-quality sunscreens with SPF (sun protection factor) ratings of at least 15.Look for sunscreens that block both UVA and UVB light.Apply sunscreen at least 30 minutes before going outside, and reapply it frequently.Use sunscreen in winter, too.Examine the skinregularly for development of suspicious growths or changes in:ColorSizeTextureAppearanceAlso note if an existing skin sore bleeds, itches, is red and swollen (inflamed), or is painful.ReferencesHabif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby; 2004:724-735.Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKena WG. Clinical Oncology. 3rd ed. Orlando, Fl: Churchill Livingstone; 2004:449-452.Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001:772-773.Neville JA, Welch E, Leffell DJ. Management of nonmelanoma skin cancer in 2007. Nat Clin Pract Oncol.2007;4(8):462-469.Eigentler TK, Kamin A, Weide BM, et al. A phase III, randomized, open label study to evaluate the safety and efficacy of imiquimod 5% cream applied thrice weekly for 8 and 12 weeks in the treatment of low-risk nodular basal cell carcinoma. J Am Acad Dermatol. 2007;57(4):616-621.
