Lyme Disease: A Whodunit Tale

Some medical advances begin with old-fashioned detective work. Lyme disease, which was unknown in this country prior to 1975 is a good example.  That fall, two mothers from Old Lyme, Connecticut convinced the state Department of Public Health and Yale University to explore a mysterious outbreak of cases of inflammatory arthritis among the town’s children, because they were unsatisfied with the explanations they had been given for the cause. The investigation that winter centered on thirty-nine children and twelve adults from Old Lyme, all of whom had developed painful swelling of one or more joints between June and September.

Clues in clinical histories

Although blood tests and physical exams of the affected people had not previously revealed any known cause for the painful, swollen joints, investigators noted that there were striking similarities in the patients’ histories. Especially notable was a peculiar spreading rash that appeared about a month prior to the development of the arthritis and resembled an archer’s bull’s eye target. The affected people also lived close to one another, all in heavily wooded areas. The researchers concluded that the area where the cases clustered and the time of year in which they occurred were both crucial clues to the mystery. They believed that the illness could be an unknown type of infection but would have to await the next disease “season” for confirmation of this theory.

More clues in old European medical literature

In the meantime, investigators began combing through European medical literature, where they discovered similar descriptions of rashes going back to 1909. Over time, the Europeans had named the skin lesion erythema migrans and associated it with an illness that was similar to the one being reported in Connecticut, although without the arthritis. Some European reports mentioned tick bites in conjunction with the rashes, as well as successful treatment with antibiotics. Back in Connecticut, the next summer produced thirty more cases of what was by then being called “Lyme arthritis,” which investigators now believed was some kind of infection transmitted during outdoor activity.

Figuring out the tick relationship

The next pieces of evidence came from field studies of ticks. The distribution of a particular type of tick called Ixodes scapularis (variously known as the blacklegged tick, deer tick, or bear tick) near Old Lyme matched the distribution of local arthritis cases. Tick autopsies conducted in New York on Shelter Island, another hot spot for this mystery arthritis, showed that most of the ticks carried a spiral-shaped bacterium called Borrelia burgdorferi. Blood tests on affected individuals for antibodies to this organism tied it to the clinical cases of arthritis. Over the next two decades, the explosion of the deer population carrying the tick made the disease more common and widely known.As knowledge about and experience with the new disease accumulated, Lyme arthritis was renamed Lyme disease.

Early  Lyme disease symptoms

Lyme disease symptoms include an early stage of fatigue, muscle and joint pains, swollen glands, and headaches and fever that begin days to weeks after the infected tick bite. These symptoms represent the immune system’s response to the bacterial invasion. If a bull’s eye rash at the site of a former tick bite is present, diagnosis is easy. If not, diagnosis depends on a clear history of a tick bite and on the development of antibodies to the organism, which usually occurs later than the first few weeks of the illness.

Later symptoms

Left untreated, some, but not all infected patients develop symptoms within the next few weeks to months after the infected tick bite. Symptoms include arthritis, nerve pains, facial nerve paralysis, heart palpitations, shortness of breath, and chest pains. An even less common late phase that can occur up to two years after an infected tick bite might include migrating joint pains, muscle aches, abnormal muscle movements, weakness, heart arrhythmias, and cognitive complaints such as memory problems. These symptoms are not well understood and may represent a combination of the body’s ongoing fight against persistent bacteria and an autoimmune response that they trigger.

Treatment

Treatment of Lyme disease with oral antibiotics, either doxycycline or amoxicillin, is usually curative. If an infected tick is attached for more than thirty-six hours (the least amount of time it takes for transmission of the infection) and was encountered in an area where more than 20 percent of the deer tick population carries Borrelia burgdorferi, most patients are given a prophylactic one-time dose of doxycycline. Otherwise, treatment with antibiotics for two to four weeks begins as soon as the diagnosis of Lyme disease is made. The earlier the treatment, the faster the disease responds and symptoms subside. Late-phase treatment of neurological, cardiac, or arthritic symptoms may require intravenous delivery of antibiotics over longer periods. Although rare cases of persistent symptoms after treatment exist, no study has yet shown enough benefit from very long-term antibiotic use to justify the potential adverse effects of such a treatment.

Prevention of tick bites

Prevention of Lyme disease is the best way to deal with the illness, and there are things you can do to protect yourself. In the states where most cases occur (the New England states and New York, New Jersey, Maryland, Virginia, Wisconsin, and Minnesota), be aware that ticks tend to cling to high grasses and shrubbery in areas where deer roam. By hiking in the center of paths, away from tall grasses and shrubs, and wearing protective clothing, such as long sleeves and pants, you can reduce the chances of a tick bite. Shirt tails should be kept tucked in at the waist, sleeves should be kept closed at the wrists, and pants cuffs should be kept tucked into socks at the ankles. Additionally, spraying with insect repellent containing 20 to 30 percent DEET can help.

Self-examination is very important after potential tick exposure

The type of tick that transmits Lyme disease is Ixodes scapularis. It may be either a six-legged, immature tick nymph the size of a poppy seed or the slightly larger, eight-legged mature tick. Both forms excrete an anesthetic in their saliva that prevents you from feeling their bite, so close examination of your body is necessary after potential exposure. Bathe within two hours of coming inside and do a full body exam, with the aid of a mirror, paying close attention to areas covered with hair. Inspect all gear, clothing, and pets for ticks, and tumble clothing in a dryer at high heat to kill any hidden ticks.

Tick removal

Should you find an attached tick on your body, to remove it place the tip of a clean, fine-tipped tweezer as close to the skin as possible and pull gently, in a straight line. Dispose of all ticks in a toilet or drown them in alcohol and then seal them in a plastic bag for disposal. Clean bites with alcohol or iodine. Because the transmission of an infection from a tick to a human requires thirty-six to forty-eight hours of attachment, ridding yourself of ticks in the first twenty-four hours is effective prevention. Longer attachments that occur in high-risk parts of the country merit a single dose of doxycycline within seventy-two hours of a bite. Otherwise, be alert for symptoms or a rash, and seek treatment as soon as possible if they occur.  (See blow for a link to an interesting tick removal tool.*)

Research continues

The detective work surrounding the unraveling of the Lyme disease mystery continues today in the laboratory. Now researchers tend to focus on the rare people who, despite receiving adequate antibiotic treatment after contracting Lyme disease, experience persistent, unexplained, or recurring symptoms. These people remain almost as much of a mystery to researchers today as the initial thirty-nine children and twelve adult with arthritis were to researchers in the mid-1970s.

 

*Tick removal tool

https://www.thegrommet.com/tickease?utm_campaign=20180626&utm_content=49931&utm_medium=email&utm_source=CC&trk_msg=77TUPK4NDPL4R992MUGHP52NOS&trk_contact=4ACPOO38FT83AKKO084SUBGRPC&trk_sid=ICRD996NV2C3PQ9D216CFKVDLG

 

Skin Cancer: Common and Commonly Curable

Babies arrive in the world with soft, smooth, and usually flawless skin. Old men and women leave the world wrinkled, mottled, spotted, and scarred. In between, the skin replaces itself many hundreds of times and in the process accumulates enough DNA damage to make skin cancer the most common of all cancers, with more than 2 million cases occurring in the United States each year. Fortunately, most skin cancers stay put in the locations where they start. They don’t invade nearby tissues and don’t spread through the base of the skin to travel to other parts of the body. Skin cancer is largely curable by removal alone.

Different skin cells and different skin cancer names

The three most common types of skin cancer arise from cells that grow in the epidermis, or outermost layer of the skin. The inner layer of the epidermis is made up of basal cells. Basal cells regularly reproduce themselves in order to make squamous cells, which are replacement skin cells and form a middle epidermal layer. This layer also contains cells called melanocytes. Melanocytes produce melanin, the pigment that gives skin its color. The outer layer of the epidermis consists of dead skin cells that are constantly being shed. The most common skin cancers come from these three types of skin cells: basal cells, squamous cells, and melanocytes. All three types of cancer are more common in fair-skinned, light-haired, light-eyed people. All three are also related to lifetime sun exposure.

Basal cell skin cancer

Basal cell cancer is the most common type of skin cancer, accounting for 80 to 90 percent of reported skin cancer cases. It is also the most benign skin cancer. Basal cell cancers begin with errors in a cell’s DNA, which serves as instructions for building squamous cells from basal cells. The abnormal cells that are created by this damaged DNA form a tiny area of skin that is different from surrounding normal skin. Typically, it looks like a little dome, with a waxy, pale appearance. Over time it may develop tiny blood vessels around it. It might bleed easily or develop a sunken center or a crusted top. Sometimes the color may be a little darker or rosier than that of the surrounding skin.

Basal cell cancers grow slowly and very rarely travel to other parts of the body. That said, they can invade nearby tissues, and the earlier they are removed, the less likely they are to recur (and the smaller the scar caused by their removal will be). Basal cell cancers occur most commonly on areas of the body exposed to the sun, especially the scalp, forehead, and corner of the nose. They are also more common in people who have been intermittently exposed to the sun without protection. Basal cell cancers take many years to develop, and by age sixty-five, about 50 percent of the population will have developed at least one such cancer. Within five years of treatment of one basal cell cancer, one-half of patients will develop a second one. Because of the popularity of tanning, both indoors and out, basal cell cancers are now appearing in some people before middle age.

Squamous cell skin cancer

Squamous cell cancers can occur in areas of the body that are not generally exposed to the sun, like the mouth and the genital region. However, when squamous cell cancers appear on the skin, they typically develop in areas that show other signs of sun damage—wrinkling, freckling, mottling, thinning, and sagging. They may also evolve from solar, or actinic, keratoses, which are considered precancerous markers of sun damage. Usually appearing as small red spots (under a quarter of an inch in diameter), solar keratoses have some white scaling on their surfaces. Some are sore and tender, and thickening with increased tenderness can indicate a progression to a skin cancer. Squamous cell cancers can be flat and scaly patches of skin or firm, red nodules or non-healing sores. Unlike basal cell cancers, squamous cell cancers, particularly those on the lip, can penetrate deeper layers of skin and travel to other parts of the body by way of the lymphatic system, though this spread is uncommon. If many precancerous lesions are present, treatment with chemotherapeutic creams helps prevent cancer development.

Melanomas

Like basal cell and squamous cell cancers, melanocyte cancers, which are known as melanomas and appear similar to moles, more commonly occur in fair-skinned people and are also related to sun exposure. It is no coincidence that the highest rates of melanoma in the world are in Australia and South Africa, two highly sunny areas colonized by fair-skinned people who are genetically better suited to the gray skies of northern climates.

Melanomas must be distinguished from normal moles, which develop in virtually all people. The average adult has twenty-five moles with varying degrees of pigmentation. Many “rules” exist for helping physicians decide whether a mole might be cancerous. For example, moles that are asymmetrical in shape and color, have irregular margins, and are larger than a pencil eraser are often considered suspect. However, none of these “rules” is a reliable way to tell if a mole is cancerous. More reliable suspicions are generally based on observations concerning mole development. The development of a new mole, particularly on the back or the legs, that grows over a number of years is definitely something that should be discussed with a physician.

A full 70 percent of melanomas are what are termed superficial spreading melanomas and are curable if caught when they are less than 1mm thick. Another 7 to 10 percent of melanomas, those that are deep blue-black or purple nodules, tend to spread more readily to other parts of the body. Rarer yet are melanomas in odd locations like the eye, under a nail, on the palm of the hand, or on the sole of the foot. These, too, are more dangerous.

Like basal cell and squamous cell cancers, the treatment for a melanoma is removal. There are a variety of different ways to remove skin cancers, ranging from scraping and cauterizing to a surgical excision with microscopic monitoring to find the edges of the tumor. Cure rates are high—in the 98 percent range, particularly when the tumors are small. If a tumor does spread to nearby tissues, it can still be cured, though with more surgical scarring. Metastatic melanomas do not respond well to conventional cancer treatments as a rule but may react differently to newly developing targeted immunological treatments.

Screening for skin cancer: no controversy 

In contrast to the confusion surrounding screening tests for some other types of cancer, clarity is the mark of medical advice about skin cancer. It helps if you know what to look for and to seek a medical opinion about any suspicious skin spots. Most often, doctors will recommend biopsy of a suspicious lesion as the surest way to make a diagnosis, and patients can expect that removal will be part of the cure for any cancers that are found. You won’t ever regain the skin of a newborn, but you do not need to have skin cancer.

 

Your role in skin cancer prevention

• Beginning early in life, protect your skin, particularly the skin on your face, scalp, ears, lips, back , arms, and hands. Use hats, shirts, and sunscreen (at least 30 SPF) to help block the harmful rays of the sun.
• Avoid prolonged sun exposure when the sun is high in the sky.
• At least once in middle age, have a professional examination of all your skin. If you are fair-skinned, and/or have sun damaged skin, heed your physician’s advice if he suggests more regular checkups. The American Academy of Dermatology sponsors free screening exams every May.
• Keep an eye on your skin and have new, enlarging, color-changing, non-healing or bleeding spots checked by a professional.

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