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Powered by information and insights from The Merck Manuals Vol. 1 — 2005Safeguard Dogs and Cats The Darkfrom Summer’s Pesky Critters Side of SunlightSummer Rashes and Bites Identifying the Bumps and Spots on Your Skin Common Skin Disorders Skin Cancer Our expert helps you to recognize the different types of skin cancers

The Dark Sideof Sunlight:Skin Damage andPremature Aging 4

Basking in the warm summer sun might feelgood, but ultimately, your health may suffer.During the summer, most effect on skin. UV light in Sunburn you probably small amounts is beneficial, spend most of because it helps the body produce Sunburn results from a briefyour time outside. But vitamin D. However, larger (acute) overexposure to UV light.whether you bake in the amounts of UV light damage DNA The amount of sun exposuresun at the beach or (the body’s genetic material) and required to produce a burn variessimply catch some rays alter the amounts and kinds of with each person’s pigmentationwhile you jog, picnic, or chemicals that the skin cells make. and ability to produce moredo errands, your health melanin.may pay a price. Too The skin undergoes certainmuch sun exposure can changes when exposed to UV light “The skinincrease your chances for to protect against damage. Theskin cancer. In fact, 1 in 5 epidermis (the skin’s uppermost undergoesAmericans will eventually layer) thickens, blocking UV light. certain changesdevelop skin cancer, The melanocytes (the pigment- when exposedaccording to the American producing skin cells) make to UV light toAcademy of Dermatology. increased amounts of melanin, protect againstThe good news is that which darkens the skin, resulting inyou can take steps to a “tan.” The more sun exposure a ”damage.protect your skin from person has and the fairer his skin,the sun’s damaging rays. the higher the risk of skin cancers. Sunburn results in painful reddened skin. Severe sunburnSunlight and Skin The key to minimizing the may produce swelling and blisters.Damage damaging effects of the sun is Symptoms may begin as soon as avoiding further sun exposure; one hour after exposure andThe skin shields the rest of the damage that is already done is typically reach their peak after onebody from the sun’s rays. difficult to reverse. Moisturizing day. Some severely sunburnedUltraviolet (UV) light, although creams and makeup help hide people develop a fever, chills, andinvisible to the human eye, is the wrinkles. Chemical peels, alpha- weakness and on rare occasionscomponent of sunlight that has the hydroxy acids, and laser skin even may go into shock resurfacing may improve the appearance of thin wrinkles and irregular pigmentation. Deep wrinkles and significant skin damage, however, are unlikely to be reversed.Want to subscribe to Your Health Now? 5Log onto www.YourHealthNow.com.

(characterized by low blood Before exposure to strong direct In the United States, sunscreenspressure, fainting, and profound sunlight, a person should apply a are rated by their sun protectionweakness). Several days after a sunscreen, an ointment or cream factor (SPF) number – the highersunburn, people with naturally fair containing chemicals that protect the SPF number, the greater theskin may have peeling in the the skin by filtering out UV light. protection. Sunscreens ratedburned area, usually accompanied Sunscreens contain substances, between 0 and 12 provide minimumby itching. These peeled areas are such as para-aminobenzoic acid protection; those rated between 13even more sensitive to sunburn for (PABA) and benzophenone, that and 29 provide moderate protection;several weeks. absorb UV light. Sunscreens those rated 30 and above provide containing PABA must be applied maximum protection.The best – and most obvious – way 30 to 45 minutes before going outto prevent sun damage is to stay in the sun or into the water.out of strong, direct sunlight. Many sunscreens contain bothClothing and ordinary window glass PABA and benzophenone orfilter out most of the damaging other chemicals; theserays. Water is not a good filter: combinations provide protectionultraviolet A (UVA) and ultraviolet B from a broader range of UV light.(UVB) light can penetrate a foot of Many sunscreens claim to beclear water. Clouds and fog are also either waterproof or water-not good filters of UV light; a resistant, but most of theseperson can get sunburned on a nonetheless require morecloudy or foggy day. frequent application in people who are swimming or sweating. 6

Cold tap water compresses can soothe raw, hot Are Tans Healthy?areas, as can skin moisturizers without anestheticsor perfumes that might irritate or sensitize the In a word – no. Although a suntan is often consideredskin. Certain anti-inflammatory drugs help relieve an emblem of good health and of an active, athletic life,pain and inflammation. Corticosteroid tablets also tanning for its own sake has no health benefit and ismay help relieve the inflammation but are used actually a health hazard. Any exposure to UVA or UVBonly for the most serious burns. Specific antibiotic light can alter or damage the skin. Long-term exposureburn creams are required only for severe blistering. to natural sunlight causes skin damage and increasesMost sunburn blisters break on their own: they do the risk of skin cancer. Exposure to the artificial sunlightnot need to be popped and drained unless they used in tanning salons is harmful as well, even thoughare still intact after three or four days. the UVA lights used in these establishments are somewhat less likely to produce skin cancer. QuiteSunburned skin begins healing by itself within simply, there is no “safe tan.”several days, but complete healing may takeweeks. After burned skin peels, the newly exposed Self-tanning, or sunless, lotions do not really tan thelayers are thin and initially very sensitive to sunlight skin but, rather, stain it. They therefore provide a safeand must be protected for several weeks. ■ way to achieve a tanned look without risking dangerous exposure to UV rays. However, because they do not Information contained in this article comes from The Merck increase melanin production, self-tanning lotions do not Manuals. For more information, visit www.YourHealthNow.com/ offer protection from the sun. Therefore, sunscreens skincancer or search The Merck Manual Home Edition. should still be used during exposure to sunlight. Results with the use of self-tanning lotions may vary, depending on a person’s skin type, the formulation used, and the manner in which the lotion is applied.Aging and The Skin As people age, the skin tends to become thinner, less The number of sweat glands and blood vessels also elastic, drier, and finely wrinkled. However, exposure to decreases, and blood flow in the deep layers of the sunlight over the years contributes to wrinkling and to skin decreases. Normally, heat is moved from the making the skin rough and blotchy. The effects of inner parts of the body through blood vessels to exposure to sunlight can be seen when skin that is the surface of the body. When blood flow normally exposed to sunlight, such as that on the face, decreases, less heat leaves the body, and the is compared with skin that is usually covered, such as body cannot cool itself as well. Thus, older that on the buttocks. People who have avoided people are more likely to develop disorders exposure to sunlight often look much younger than their due to overheating, such as heat stroke. actual age. Also, the skin tends to heal more slowly when blood flow is decreased. The layer of fat under the skin thins and is replaced by more fibrous tissue. The fat layer acts as a cushion for The number of pigment-producing cells the skin, helping protect and support it. The fat layer (melanocytes) decreases. Thus, the skin has also helps conserve body heat. As this layer thins, the less protection against ultraviolet (UV) skin is torn more easily, wrinkles are more likely to radiation, such as that from sunlight. develop, and tolerance for cold decreases. Information contained in this article comes from The number of nerve endings in the skin decreases. The Merck Manuals. For more information, visit As a result, sensation, including sensitivity to pain, www.YourHealthNow.com/agingskin may be reduced, and injuries may be more likely. or search The Merck Manual Home Edition. 7

Identifying the Bumpsand Spots on Your SkinSkin growths are A seborrheic wart is a small, common among rough, irregularly shaped, flesh- older people. Most colored or dark bump. The surfaceare noncancerous (benign). is waxy or scaly. It can look pastedThat is, they may enlarge, or stuck on to the skin. Thesebut they do not spread to warts usually appear during middleother parts of the body. or old age, usually on the torsoCommon noncancerous and temples.growths include age spots,most moles, seborrheicwarts (seborrheic keratoses),skin tags (acrochordons),and cherry angiomas(hemangiomas). What causesthese growths is unclear.Age spots are light brown, flat seborrheic wartsspots, similar to freckles. Theydevelop after years of exposure tothe sunlight. Thus, they appearmost often on areas usuallyexposed to sunlight – the hands,forearms, and face. They aresometimes called liver spots,although they are unrelated to theliver. Dermatologists can recommendcreams or ointments that maylighten the spots after several weeksof frequent, regular applications.A mole is a colored (usually dark), Skin tags are soft, flesh-coloredpainless spot that can be flat or or dark bumps that may beraised. They can appear anywhere connected to the skin by a stalk.on the body. Once formed, Most often, they develop on themoles remain for decades. neck or in the armpit.Most moles are harmless, butsome become cancerous. continued on page 278 Need help paying for your medicine? Visit www.merckhelps.com.

From the Guest Editor Ellen S. Marmur, M.D. Chief of the Division of Dermatologic & Cosmetic Surgery Mount Sinai Medical Center, New York CityThe ABCDs of Skin Self-Exams 10

“ ”Knowing theWhen performing a self-exam, remember to inspectevery inch of your body. skin, the majority of which are Melanoma, normal. Some growths and spots, the deadliestbasics of early particularly moles, however, may form of skinskin cancer be skin cancer. Recognizing new cancer, candetection is the or suspicious growths is important have manykey to survival. in potentially spotting cancer early. features and Self-examination of your skin is is likely to the best way to detect the early spread to warning signs of skin cancer. other parts of the body if not This is vital because the sooner it treated early. is caught, the better the chancesWhether you’ve spent your for successfully treating it. ABCDs of Self-Examssummer in the sun or haveavoided the outdoors for the past There are three types Which moles might be suspicious?10 years, it is wise to check your of skin cancer: When performing a self-exam,skin regularly. Skin cancer is the remember the ABCDs:most common form of cancer, Basal cellaccounting for nearly half of all the carcinoma, Asymmetrical – If you drew acancers in the United States. the mostEvery year, more than one million common line down the middle of aAmericans develop skin cancer, skin cancer, suspicious mole, it would not can vary create matching halves.and the number one preventable greatly in Borders – Edges appear uneven,cause is sun damage. appearance. For example, it may appear as a scalloped, or like an “oil slick”.But many cases of skin cancer pearly-pink plaque or sore that Color – Multiple colors or differentcould be prevented if more people doesn’t heal.followed simple precautions, such shades of brown, black, red, blue,as wearing a broad-spectrum Squamous gray, or white.sunscreen or sunblock and a wide- cellbrimmed hat. Even with the best carcinoma Diameter – Larger than aefforts, however, sometimes our often appearspast exposure to the sun can as a raised pencil eraser (about six millimeterscome back to haunt us. bump that or one-fourth inch). may breakMany people have freckles, open and form a scab in the Want to subscribe to Your Health Now?birthmarks, and moles on their center. It is more likely to invade Log onto www.YourHealthNow.com. the deeper layers of the skin. 11

The ABCDs of Skin Self-Exams Most of the time, melanomas and Skin Self-Exam From Head to Toecontinued from page 11 other skin cancers can be easily spotted with a monthly self-exam. When performing a skin self-exam, look for anyIn my practice, I also recommend If you spot any new, suspicious, changes in existing moles, the appearance of newthat patients look for other signs or unusual growths on your skin, ones or anything that seems unusual. For theof skin cancer, including moles see changes in the size, color, exam, you will need a bright light, a full-lengththat suddenly rise, easily bleed, or or texture of old moles or skin mirror, a hand-held mirror, two chairs or stools,have white circles around them. growths, or have a cut or wound and a hair-dryer. that doesn’t seem to heal, contactInspecting From a dermatologist or other health- Examine yourHead to Toe care professional. When it is head and face. detected at an early stage, skinWhen performing a self-exam, cancer can be treated effectively Check your hands,remember to check every inch of most of the time, and is usually including fingernails,your body – from the top of your curable. However, once the cancer and your elbows,head to the bottom of your toes. spreads to other parts of the body, arms, and underarms.Suspicious moles can appear on it is difficult to stop and canany part of the body, not just areas be deadly. Inspect yourthat have been exposed to neck, chest,sunlight. The goal is to look for any Just as breast self-exams have and stomach.changes in existing moles, the helped women detect breast Women alsoappearance of new ones, or cancer early, when the chances for should checkanything that seems unusual. survival are the greatest, skin self- under their exams can help many men and breasts.Start with your head and face. women catch skin cancer earlyInspect your scalp using a hair- before it becomes a serious With your back todryer to part your hair, then concern. Both the National Cancer the mirror, useinspect the rest of your face, Institute and American Academy the hand mirrorneck, ears, mouth, and lips. of Dermatology recommend that to inspect theEven examine your eyes since people perform skin self-exams back of yourmelanoma can sometimes begin every month. This, along with neck, shoulders,in the eye. Use a mirror to check yearly skin checks by a upper arms,hard-to-see spots, such as your dermatologist, is your best line of back, buttocks,back and shoulders. defense for protecting your skin and legs. health and lowering your chancesAlso examine spots that might not for developing a potentially life- Sitting down, checkseem obvious, such as your threatening cancer. ■ your legs and feet,underarms, fingernails, between including your soles,the toes, the buttocks, the groin, as well as yourand the soles of your feet. genitals.Women also should check undertheir breasts. 12 Illustrations by John Riddle

Common Skin DisordersInformation on skin conditionsfrom dryness to rosacea. Most of the time, dry skin, unsightly growths, and other skin problems are nothing more than a cosmetic nuisance. But sometimes they may signal a more serious problem. Here’s information about some of the more common skin disorders and how to treat them. Psoriasis Psoriasis usually starts as one or more small patches on the scalp, elbows, knees, back, or buttocks. The patches typically have thick, silvery scales, which tend to flake off. Some people never have more than one or two small patches, and others have patches covering large areas of the body. The psychologic distress caused by psoriasis can be severe. 14

People with rosacea should avoid...spicy foods, alcohol, coffee, and other caffeinated beverages.“Psoriasis persists throughout life thinned with ointments containing”but may come and go. Symptoms salicylic acid, which make theare often diminished during the other drugs more effective.summer when the skin is exposedto bright sunlight. Some people Phototherapy (exposure tomay go for years between ultraviolet light) also can help clearoccurrences. Flare-ups often result up psoriasis for several months atfrom conditions that irritate the a time. Traditionally, treatment hasskin, such as minor injuries and been with phototherapy combinedsevere sunburn. Sometimes flare- with the use of psoralens (drugsups follow infections, such as that make the skin more sensitivecolds and strep throat. Flare-ups to the effects of ultraviolet light).are more common in the winter This treatment is called PUVAand after stressful situations. (psoralens plus ultraviolet A).Psoriatic arthritis produces joint Some doctors are now usingpain and swelling. narrow-band ultraviolet B (UVB) treatments, which are equally effective but avoid the need to use psoralens and the side effects they cause, such as extreme rosacea sensitivity to sunshine. common in alcoholics. Occasionally, Rosacea rosacea appears on the torso, arms, and legs rather than on the face. Rosacea usually appears during or after middle age and is most People with rosacea should avoid common in people of Celtic or foods that cause the blood vessels Northern European descent who in the skin to dilate – for example,psoriasis have fair complexions. The skin spicy foods, alcohol, coffee, and over the cheeks and nose other caffeinated beverages.Nearly everyone with psoriasis becomes red, often with small Certain antibiotics taken by mouthbenefits from skin moisturizers pimples. The skin may appear thin relieve rosacea. Antibiotics that are(emollients). Other topical agents and frail, with small blood vessels applied to the skin are alsoinclude corticosteroids, often used visible just below the surface. The effective. In rare cases, antifungaltogether with calcipotriene, a skin around the nose may thicken, creams are used. Corticosteroidsvitamin D derivative, or coal or making it look red and bulbous applied to the skin tend to makepine tar. Very thick patches can be (rhinophyma), which is particularly rosacea worse.Looking for answers to your health questions? 15Visit www.mercksource.com.

When the Skin Is Dry WartsNormal skin owes its soft, pliable texture to its Warts are caused by viruses. Most warts arewater content. To help protect against water loss, harmless, although they may be quite bothersome.the outer layer of skin contains oil, which slows The exceptions are certain types of genital wartsevaporation and holds moisture in the deeper that sometimes cause cervical cancer in women.layers of skin. If the oil is depleted, the skin Warts are classified by their location and shape.becomes dry. Common warts (verrucae vulgaris), which almostDry skin (xerosis) is common, especially in people everyone gets, are firm growths that usually have apast middle age. Common causes are cold weather rough surface. They are round or irregularly shaped;and frequent bathing. Bathing washes away surface are gray, yellow, or brown; and are usually less thanoils, allowing the skin to dry out. Dry skin may one-half inch across. Generally, they appear on areasbecome irritated and often itches – sometimes it that are frequently injured, such as the knees, face,sloughs off in small flakes and scales. Scaling most fingers, and around the nails (periungual warts).often affects the lower legs. Rubbing or scratchingdry skin can lead to infection and scarring. Plantar warts develop on the sole of the foot, where they are usually flattened by the pressure ofA form of severe dry skin is called ichthyosis. walking and are surrounded by thickened skin.Ichthyosis can be an inherited disorder or can They tend to be hard and flat, with a rough surfaceresult from a number of other medical problems, and well-defined boundaries.such as an underactive thyroid gland, lymphoma,AIDS, and sarcoidosis. Filiform warts are long, narrow, small growths that usually appear on the eyelids, face, neck, or“Taking fewer The key to lips. treatingbaths allows simple dry Flat warts, which are more common in childrenprotective oils to skin is keeping and young adults, usually appear in groups as the skin moist. smooth yellow-brown, pink, or flesh-colored spots, Taking fewer most frequently on the face and tops of the hands. The beard area in men and the legs in women areremain on baths allows also common locations for flat warts, where they protective oils may be spread by shaving.the skin.” to remain on In general, warts can be removed with chemicals, the skin. cut off, frozen off, or burned off with a laser or Moisturizing electrical current. ointments orcreams containing petroleum jelly, mineral oil, or Itchingglycerin also can hold water in the skin. Harshsoaps, detergents, and the perfumes in some Skin disorders that cause severe itching include infestations with parasites (scabies, mites, or lice),moisturizers irritate the skin and may further dry it. insect bites, hives, atopic dermatitis, and allergic and contact dermatitis. Systemic diseases that canWhen scaling is a problem, solutions or creams cause itching include liver disease, kidney failure,containing salicylic or lactic acid or urea may helpremove the scales. For some forms of severeichthyosis, creams containing substances related tovitamin A help the skin shed excessive scales. 16 Need help paying for your medicine? Visit www.merckhelps.com.

“lymphomas, leukemias and other drugs to see if the itching isThe act of scratching can itself irritate the skin andlead to more itching, creating an itching-scratching-itching cycle.”blood disorders, and, occasionally, relieved. A biopsy or skin scraping from some conditions, such as limited to a small area. Itchingthyroid disease, diabetes, and may help identify the cause, poison ivy, may require high-cancer. Many drugs can cause including an infectious one. strength corticosteroid creams.itching. Itching is also common For itching of any cause, bathing However, only mild corticosteroids,during the later months of should be kept brief and preferably such as 1% hydrocortisone,pregnancy. in cool or lukewarm water with should be applied to the face and very little or no soap. The skin genitals. Oral corticosteroids areOften, contact with wool clothing should be patted dry gently rather sometimes used when large areasor irritants, such as solvents or than rubbed vigorously. Many of the body are involved. Whencosmetics, causes itching. Dry people with itching benefit from fungal, parasitic, or bacterialskin also can result from cold an over-the-counter moisturizing infections cause itching, topical orweather or prolonged exposure to cream applied right after bathing. systemic drugs may be required.water. Hot baths typically worsenitching. The act of scratching can The moisturizer should be odorlessitself irritate the skin and lead to and colorless, because additives Lice Infestationmore itching, creating an itching- that provide color or scent mayscratching-itching cycle. Prolonged irritate the skin and even cause Lice are barely visible, winglessscratching and rubbing can thicken itching. Fingernails, especially insects that spread easily fromand scar the skin. children’s, should be kept short to person to person by body contactItching that lasts longer than a few minimize abrasions from and shared clothing and otherdays or that comes and goes scratching. Coating the affected personal items.frequently without an obvious area with soothing compounds,cause usually requires testing. If such as menthol, camphor, Head lice infest the scalp hair. Thean allergy is suspected, skin tests chamomile, eucalyptus, and infestation is spread by personalmay be performed. The number of calamine, also can help. contact and by shared combs,eosinophils, a type of white blood brushes, hats, and other personalcell, may be checked as well, Taking antihistamines by mouth items. Head lice are a commonbecause a high number may may decrease itching. Generally, scourge of school children of allindicate an allergic reaction. If a creams containing antihistamines social strata. should not be used, becausesystemic disease is suspected, they can themselves cause an Body lice usually infest peopleblood tests are usually performed allergic reaction. who have poor hygiene and thoseto check liver function, kidneyfunction, and blood sugar levels. Corticosteroid creams decrease living in close quarters or crowdedSometimes, the doctor may have inflammation and control itching institutions.a person discontinue one or more and may be used when itching is 17

Pubic lice (“crabs”), which infest Lice themselves are sometimes living and dead nits. Removalthe genital area, are typically hard to find, but their eggs are requires a fine-tooth comb – whichspread during sexual contact. readily apparent. Female lice lay is often packaged with theThese lice may infest the chest shiny grayish white eggs (nits) that medication – and careful searchinghair, underarm hair, beard hair, can be seen as tiny globules firmly (hence the term “nit-picking”).eyebrows, and eyelashes Because the nits are so stronglyas well. stuck to hairs near their base. stuck to the hair, several With chronic scalp nonprescription preparations areLice infestation causes infestations, the nits available to loosen them. The nitssevere itching in the grow out with the of body lice are destroyed simplyinfested area. hair and therefore by throwing away infested clothing.Intense scratching can be found someoften breaks the distance from the Sources of infestation (combs,skin, which can scalp, depending hats, clothing, and bedding) shouldlead to bacterial on the duration of be decontaminated by launderinginfections. the infestation. or dry cleaning. Topical drugs, in the Seborrheic Dermatitis form of shampoo, cream or liquid, are Seborrheic dermatitis occurs most applied for 10 minutes often in infants, usually within the and then rinsed out. All first three months of life, and louse treatments are between the ages of 30 and 70. The disorder is more common in repeated in seven to men, often runs in families, and is 10 days to kill newly worse in cold weather. A form of hatched lice. seborrheic dermatitis also occurs in as many as 85 percent of people After drug with AIDS. application, nits must be Seborrheic dermatitis usually removed begins gradually, causing dry or manually, greasy scaling of the scalp because drugs (dandruff), sometimes with itching do not kill all nits but without hair loss. In more and because it severe cases, yellowish to reddish is not possible scaly pimples appear along the hairline, behind the ears, in the ear to distinguish between 18

Seborrheic dermatitis occurs most often in infants, usually within the first three months of life, and between the ages of 30 and 70.“canal, on the eyebrows, on the”bridge of the nose, around the nose,on the chest, and on the upperback. In infants younger than onemonth of age, seborrheicdermatitis may produce a thick,yellow, crusted scalp rash (cradlecap) and sometimes yellowscaling behind the ears and redpimples on the face. Frequently, astubborn diaper rash accompaniesthe scalp rash. Older children andadults may develop a thick,tenacious, scaly rash with largeflakes of skin.The scalp can be treated with a On the face, only mild The scalp can also be shampooedshampoo containing pyrithione corticosteroids, such as 1% daily with mild baby shampoo, andzinc, selenium sulfide, an hydrocortisone, should be used. 1% hydrocortisone cream can beantifungal drug, salicylic acid and Even mild corticosteroids must be rubbed into the scalp. ■sulfur, or tar. The person usually used cautiously, because long-uses the medicated shampoo term use can thin the skin and Information contained in this article comesevery other day until the dermatitis cause other problems. from The Merck Manuals. For more information,is controlled and then twice visit www.YourHealthNow.com/weekly. In adults, thick crusts and In infants and young children who skindisorders or search The Merck Manualscales, if present, can be loosened have a thick scaly rash on the Home Edition.with overnight application of scalp, salicylic acid in mineral oilcorticosteroids or salicylic acid can be rubbed gently into the rashunder a shower cap. with a soft toothbrush at bedtime.Often, treatment must becontinued for many weeks; if thedermatitis returns after thetreatment is discontinued,treatment can be restarted. Topicalcorticosteroids are also used onthe head and other affected areas.Want to subscribe to Your Health Now? 19Log onto www.YourHealthNow.com.

Summer Rashesand Bites 22

Your skin is fair game for bug bites and plantrashes all summer long. Here’s a look at someof these warm weather scourges.Bee stings. Mosquito of repeat contact with poison oak bites. Poison ivy. contaminated clothing and other During the lazy objects or because some parts of poison sumacdays of summer, you’re the skin are more sensitive thanunder constant assault others. The blister fluid itself is not Bee, Wasp, Hornet,from insects and contagious. The itching and rash and Ant Stingspoisonous plants when last for two to three weeks.journeying outdoors. Stings by bees, wasps, andLearn information about Recognition and avoidance of hornets are common throughoutthese summer problems contact with the plants is the best the United States. The averageand how to ease the itch prevention. Washing of the skin person can safely tolerate 10and soothe the sting. with soap and water prevents stings for each pound of body absorption of the oil if done weight. However, one sting canPoison Ivy immediately. Stronger solvents, cause death from an anaphylactic such as acetone, alcohol, and reaction (a life-threatening allergicAbout 50 to 70 percent of people various commercial products, are reaction in which blood pressureare sensitive to the plant oil probably no more effective. falls and the airway closes in aurushiol contained in poison ivy, person who is allergic to suchpoison oak, and poison sumac. Treatment helps relieve symptoms stings).Once a person has been but does not shorten the durationsensitized by contact with these of the rash. The most effective Bee stings produce immediateoils, subsequent exposure treatment is with corticosteroids. pain and a red, swollen area aboutproduces a contact dermatitis Small areas of rash are treated with one-half inch across. In some(inflammation of the skin). strong topical corticosteroids except people, the area swells to a on the face and genitals, where diameter of two inches or moreSymptoms begin from eight to 48 only mild corticosteroids, such as over the next two or three days.hours after contact and consist of 1% hydrocortisone, should beintense itching, a red rash, and applied. People with large areas ofmultiple blisters, which may be rash or significant facial swellingtiny or very large. Typically, the are given high-dose corticosteroidsblisters occur in a straight line taken by mouth. Cool compressesfollowing the track where the plant wet with water or aluminumbrushed along the skin. The rash acetate may be used on largemay appear at different times in blistered areas. Antihistaminesdifferent locations either because given by mouth may help with itching.Want to subscribe to Your Health Now? 23 poison ivyLog onto www.YourHealthNow.com.

The fire ant sting usually produces Lyme disease (erythema migrans) parts of the body. Less commonimmediate pain and a red, swollen symptoms include backache,area, which disappears within 45 named because the adult ticks nausea and vomiting, sore throat,minutes. A blister then forms, often feed on the blood of deer. swollen lymph nodes, and anrupturing in two to three days, and The bacteria that cause Lyme enlarged spleen. Although mostthe area often becomes infected. disease are transmitted to people symptoms may come and go,In some cases, a red, swollen, when an infected tick bites and feelings of illness and fatigue mayitchy patch develops instead of a stays attached for one or two persist for weeks.blister. Isolated nerves may days. Brief periods of attachmentbecome inflamed, and seizures rarely transmit disease. Abnormalities of nerve functionmay occur. develop in about 15 percent of The early-localized stage typically people. The most commonA bee may leave its stinger in the begins with a large, red spot at problems are headache, stiff neck,skin. The stinger should be the site of the bite, usually on the involvement of the tissues coveringremoved as quickly as possible thigh, buttock, trunk, or armpit. The the brain and spinal cord (asepticwithout concern for the method of spot (erythema migrans) typically meningitis), and weakness on oneremoval. An ice cube placed over expands to a diameter of six side of the face (Bell’s palsy);the sting reduces the pain. A inches (15 centimeters), often with these may persist months beforecream containing a combination of a central clearing (bull’s eye). disappearing. Nerve pain andan antihistamine, an analgesic, and About 25 percent of infected weakness may develop in othera corticosteroid is often useful. people never develop – or at leastPeople who are allergic to stings never notice – any red spot. “About 25should always carry a preloadedsyringe of epinephrine, which The symptoms of early- percent ofblocks anaphylactic or allergic disseminated Lyme disease begin infected peoplereactions. when the bacteria spread through never develop – the body from the initial bite area. or at least neverPeople who have had a severe In this stage, many people feel ill notice – any redallergic reaction to a bee sting with fatigue, chills and fever,sometimes undergo desensitization, headaches, stiff neck, and aches in spot.”areas and persist longer. Irregularwhich may help prevent future muscles and joints. Nearly halfallergic reactions. develop more, usually smaller, heartbeats (arrhythmias) and erythema migrans spots on other inflammation of the sac aroundLyme Disease the heart (pericarditis) that causes chest pain develop in eightUsually, Lyme disease occurs in percent of infected people.the summer and early fall.Children and young adults who In untreated Lyme disease, thelive in wooded areas are most late stage begins months to yearsoften infected. after the initial infection. Arthritis The bacteria that cause Lyme disease are transmitted by the deer tick (Ixodes), so deer tick 24

develops in about half of the Preventing Tick and Mosquito Bitespeople with late-stage Lymedisease. Episodes of swelling and Tick Bitespain in a few large joints,especially the knee, typically recur The possibility of contact with ticks can be minimized by staying onfor several years. The knees are paths and trails when walking in wooded areas and by not sitting oncommonly more swollen than the ground or on stone walls. Wearing light-colored clothing makespainful, often hot to the touch, ticks crawling on clothing easier to see. Applying an insecticideand, in rare instances, red. A containing diethyltoluamide (DEET) to the skin and one containingsmaller number of people develop permethrin to clothing may help protect against tick bites. (Productsneurologic abnormalities, including containing DEET can cause adverse effects and should be used onlyproblems with speech, memory, by closely following the directions on the product labels. Themood, and sleep. Sometimes American Academy of Pediatrics recommends that these productspeople who develop neurologic not be used in children less than two months old.) People who mayabnormalities have numbness or have been exposed to ticks should inspect their whole body for ticksshooting pains in the back, legs, daily. Deer ticks, which transmit Lyme disease, are very small, muchand arms. smaller than dog ticks. So people should check the whole body very carefully, especially hairy areas. Inspection is effective because ticksThe most commonly used tests must be attached for more than a day to transmit Lyme disease.measure antibodies to thebacterium in the blood. However, To remove a tick, a person should use fine-pointed tweezers to graspantibody tests alone are not the tick by the head or mouthparts right where they enter the skinadequate because they are often and should pull the tick straight off. The tick’s body should not benegative in the early stages of grasped or squeezed. Petroleum jelly, alcohol, lit matches, or anyLyme disease and are sometimes other irritants should not be used.positive in people who do not havethe disease. Mosquito BitesMost doctors do not give Mosquito control measures, which include eliminating breeding areasantibiotics to people who weresimply bitten by ticks but have no and killing larvae in the standing water where they live, are veryrash or other symptoms. Althoughall stages of Lyme disease important. People can also limit mosquito exposure by usingrespond to antibiotics, earlytreatment is the most effective in insecticide sprays in homes and outbuildings, placing screens onhelping to prevent complications.Treatment is given for three to doors and windows, using permethrin-impregnated mosquito nettingfour weeks. ■ over beds, and applying mosquito repellents containing DEET on Information contained in this article comes from The Merck Manuals. For more exposed areas of the skin. People can wear long information, visit www.YourHealthNow.com/ summerhazards or search The Merck Manual pants and long-sleeved shirts, particularly Home Edition. between dusk and dawn, to protect against mosquito bites. People subject to intense mosquito exposure can spray permethrin on their clothing before it is worn. common mosquito 25

Making Medicine Affordable ■ The Partnership for Prescription www.togetherrxaccess.com or by Assistance (PPA) provides a calling 1-800-444-4106.continued from page 13 single point of entry to more than 275 public and private Because navigating the many They can simply show their patient assistance programs. available resources can be difficult, participating discount card when More information is available at Merck has developed the Guide to filling their prescriptions and should www.pparx.org or by calling its Affordable Medicine. This free guide receive the discount from their card toll-free number 1-888-4PPA-Now. is being provided as a service to the sponsor. Free Merck medicines are community and will help answer available to qualifying low-income ■ The Together Rx Access™ Card is many important questions about seniors who have exhausted their a free program sponsored by these services. annual Medicare assistance credit, several pharmaceutical companies though the dispensing pharmacy that helps people save up to 40 To order your free guide, please fill may charge a fee. For general percent on more than 275 brand- out the business reply card inside information, please call name prescription drugs and other this magazine or visit 1-800-MEDICARE or visit prescription products, as well as www.YourHealthNow.com. ■ www.medicare.gov. savings of at least 15 percent on generic prescription medicines. Editor’s Note: Most local librariesThere are many other programs More information can be found at offer free access to the Internet.available to assist patients.Looking for answers to your health questions? 26Visit www.mercksource.com.

Identifying the Bumps and Pet Care, so those symptoms require urgentSpots on Your Skin medical attention. continued from page 20continued from page 8 Ticks are commonly found the flea life cycle. Fortunately, the between the toes of a pet’s paws,Cherry angiomas are overgrowths modern flea control products behind or inside its ears, orof blood vessels that form raised available from a veterinarian are between its legs. Ticks should bered or purple bumps or spots. long-lasting and effective against removed immediately. Grasp theThey are typically no more than both adult fleas and their eggs and tick with curved tweezers as closeone-eighth inch (three millimeters) larvae. to the skin as possible and pull itacross. They usually appear on directly out. The tick’s head, whichthe trunk. Beware of Biting Ticks may not come out with the body, also should be removed with theNoncancerous skin growths can Ticks are small, bloodsucking pests tweezers, because it can causebe removed if they are unattractive that are most often picked up tenderness and swelling. Applyingor they rub against clothing and outdoors, especially in wooded alcohol, fingernail polish, or a hotbecome irritated. Usually, they can areas. Ticks will bite and burrow match are not effective methodsbe removed in a doctor’s office their heads into the skin of a host and may cause the tick to spitwith a scalpel, scissors, liquid animal, and can remain attached for infected saliva into the bite site.nitrogen, or a laser. Sometimes a several days. Several kinds of ticks Once the tick has been removed,local anesthetic is used. can bite pets, and many carry thoroughly clean the area to infectious organisms that can prevent an infection and spray anSome skin growths in older people transmit diseases. indoor insecticide on baseboardsare cancerous (malignant). That is, and crevices in the walls and floors.they invade other tissues and For example, deer ticks canspread to other parts of the body. transmit the bacteria that causes Pets that show possibleSkin should be checked periodically Lyme disease, which often begins symptoms of a tick-related illnessfor changes. Certain changes with a circular, flat, red rash after a – loss of appetite, weakness, anshould be reported to a doctor. tick bites and stays attached to the unsteady walk, vomiting, or fever –(For more information, see body for one or two days. The should be seen by a veterinarian.“The ABCDs of Skin Self-Exams” disease can cause arthritis, Products that are effective againston page 10). neurological symptoms, fatigue, both fleas and ticks are available and vomiting, but is easy to treat if from the veterinarian. DependingA doctor should thoroughly caught early. For more on Lyme on the area of the country, a petexamine all of the skin once a year disease, see “Summer Rashes may need to be treated monthlyto check for new growths or and Bites”, page 24. throughout the year. ■changes in old growths.Sometimes a doctor removes a Dog and wood ticks can transmit The contents of this article werepiece of a growth for examination Rocky Mountain spotted fever, adapted from The Merck Veterinaryunder a microscope (biopsy). ■ symptoms of which include a rash, Manual, 9th Edition, published abdominal pain, headache, and in 2005. Information contained in this article comes from high fever. The disease occurs The Merck Manuals. For more information, mainly from March to September, visit www.YourHealthNow.com/skindisorders most commonly in the Midwest or search The Merck Manual Home Edition. and on the Southern Atlantic seaboard, and is potentially fatal; 27