Month: October 2021

Many people seek medical attention when they have diarrhea, usually when it is severe or is not improving. Doctors like myself ask questions to see what could be causing the problem: Food poisoning? Irritable bowel syndrome? Medication side effects? We also consider that diarrhea may be due to Clostridioides difficile infection (CDI).

What is C. diff infection?

CDI is a bacterial infection that can cause severe problems in the gastrointestinal tract, especially the colon. C. diff is responsible for almost half a million infections in the US each year, and it can be a recurring problem: one in six patients with this infection will get it again within two months. Sadly, one in 11 patients over age 65 who is hospitalized for CDI will die within one month of infection due to the severity of illness in CDI. Therefore, CDI is an important public health consideration, and it’s important to get treatment.

Who at risk for C. diff infection?

There are certain risk factors for developing a CDI. These include being hospitalized, having been exposed to antibiotics, or having close contact with someone who has been diagnosed with the infection. If you are immunocompromised (have a weakened immune system), you may be also at higher risk of contracting CDI or of suffering a complication from it.

A major focus of reducing the burden of CDI in the healthcare system is trying to reduce the risk of getting CDI in the hospital. This includes testing for CDI in hospitalized patients who develop new diarrhea, and then isolating those patients into their own rooms.

Prevention also includes washing your hands thoroughly with soap and water. This is a particularly important point because in healthcare settings, alcohol-based sanitizer often is used for convenience when clinicians practice preventive infection control between caring for patients. Alcohol-based sanitizer is not effective against CDI as it is for other types of infection because, unlike other bacteria, C. diff organisms can form resistant spores.

So, to protect yourself in health care settings, you should make sure the people who interact with you — doctors, nurses, medical assistants, etc. — have washed their hands prior to touching you. It can seem rude to ask someone if they have washed their hands. However, all people who work with patients receive training about hand-washing, and sometimes we simply forget in the middle of busy days, so it can be helpful to remind us.

What about CDI transmission outside of medical settings?

What is less understood is when CDI happens outside the hospital. A recent article in Emerging Infectious Diseases reported the presence of CDI in patients who became infected in a way that doctors tend not to think of as often: getting CDI from someone they know without ever being hospitalized or taking antibiotics themselves.

As physicians, we are drilled on the factors previously mentioned — prior use of antibiotics, previous hospitalization — as critical events that may cause CDI. What this research demonstrated is that people without these risk factors developed CDI by being exposed to someone with CDI in the community. It turns out that this is a common way people end up contracting CDI. During my training, we learned that it is important to remind patients newly diagnosed with CDI to be mindful of good hand hygiene, and to avoid as many contacts as possible until their CDI treatments were completed. This new research suggests that focusing on community CDI transmission should be a greater priority.

How is CDI treated?

The first round of CDI treatment is usually antibiotics (ironic, since antibiotics can cause CDI). These include metronidazole, vancomycin (in oral form only), and fidaxomicin. Every few years guidelines are reviewed and updated, but generally, different antibiotic treatment courses are given based on CDI illness severity, whether there is an infection that is failing to clear, or if a new antibiotic needs to be tried.

A promising way to treat CDI, particularly in patients who have not been helped by antibiotic therapy, is to give a fecal microbiota transplant, or FMT. This treatment involves taking a healthy person’s stool donation and administering it during an endoscopy procedure by mouth, during a colonoscopy, or in frozen form by pill. I know — taking someone else’s poop sounds so icky! However, the purpose is to introduce healthy bacteria into a gut that is sick with CDI, and the theory is that these healthy bacteria expand and make the environment harder for the C. diff bacteria to live and cause problems.

What precautions help prevent spread ofCDI?

The rules are simple for reducing your risk of CDI. If you have a weakened immune system, stay away from people who have been diagnosed with CDI. Thoroughly wash your hands with soap and water (not disinfectant) to deal with C. diff spores more effectively. When you are sick, take antibiotics only if they are necessary; doctors often feel pressured to write antibiotic prescriptions for people who have viral illnesses (for which antibiotics do not work).

Evidence is not strong for taking probiotics or eating yogurt to prevent CDI, but these approaches are low-risk ways to introduce healthy bacteria into your gut; this may be reasonable, in part because some in the medical field continue to debate their effectiveness.

Bottom line: if you are having diarrhea that just won’t go away, talk to your doctor to see if you have CDI or if there is something else causing your symptoms.

About the Author

Christopher D. Vélez, MD, Contributor

Dr. Christopher Vélez is an attending gastroenterologist in the Center for Neurointestinal Health of Massachusetts General Hospital's division of gastroenterology and the MGH department of medicine. He focuses on neurogastroenterology and motility disorders of the esophagus, … See Full Bio View all posts by Christopher D. Vélez, MD

For most Americans, a daily multivitamin is an unnecessary habit.

Are you among the one in three Americans who gulps down a multivitamin every morning, probably with a sip of water? The truth about this popular habit may be hard to swallow.

“Most people would be better off just drinking a full glass of water and skipping the vitamin,” says Dr. Pieter Cohen, an associate professor of medicine at Harvard Medical School and an internist at Harvard-affiliated Cambridge Health Alliance. In addition to saving money, you’ll have the satisfaction of not succumbing to misleading marketing schemes.

That’s because for the average American adult, a daily multivitamin doesn’t provide any meaningful health benefit, as noted recently by the US Preventive Services Task Force (USPSTF). Their review, which analyzed 84 studies involving nearly 700,000 people, found little or no evidence that taking vitamin and mineral supplements helps prevent cancer and cardiovascular disease that can lead to heart attacks and stroke, nor do they help prevent an early death.

“We have good evidence that for the vast majority of people, taking multivitamins won’t help you,” says Dr. Cohen, an expert in dietary supplement research and regulation.

Who might need a multivitamin or individual supplements?

There are some exceptions, however. Highly restrictive diets and gastrointestinal conditions, or certain weight-loss surgeries that cause poor nutrient absorption, are examples of reasons why a multivitamin or individual vitamins might be recommended. A daily vitamin D supplement may be necessary when a person gets insufficient sun exposure. Your doctor may recommend an iron supplement if you have a low red blood cell count (anemia).

Why is it hard to give up the habit of a daily multivitamin?

Surveys suggest people take vitamins to stay healthy, feel more energetic, or gain peace of mind, according to an editorial that accompanied the USPSTF review. These beliefs stem from a powerful narrative about vitamins being healthy and natural that dates back nearly a century.

“This narrative appeals to many groups in our population, including people who are progressive vegetarians and also to conservatives who are suspicious about science and think that doctors are up to no good,” says Dr. Cohen.

Unproven marketing claims for dietary supplements

Vitamins are very inexpensive to make, so the companies can sink lots of money into advertising, says Dr. Cohen. But because the FDA regulates dietary supplements as food and not as prescription or over-the-counter drugs, the agency only monitors claims regarding the treatment of disease.

For example, supplement makers cannot say that their product “lowers heart disease risk.” But their labels are allowed to include phrases such as “promotes a healthy heart” or “supports immunity,” as well as vague promises about improving fatigue and low motivation.

“Supplement manufacturers are allowed to market their products as if they have benefits when no benefit actually exists. It’s enshrined into the law,” says Dr. Cohen. It’s wise to note the legally required disclaimer on each product: “These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”

But even the strong language in this disclaimer — “not intended to diagnose, treat, cure, or prevent” — doesn’t seem to affect how people perceive the marketing claims.

Although multivitamins aren’t helpful, at least they’re not harmful. But the money people spend on them could be better spent on purchasing healthy foods, Dr. Cohen says.

About the Author

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio View all posts by Julie Corliss

At one time, replacement parts for the eyes must have seemed unimaginable. Nowadays, if the inner lens of the eye becomes clouded by a cataract, a routine surgery to swap it out with a new artificial lens restores vision.

But what happens if the outer lens of the eye (the cornea) becomes damaged or diseased? You can have that replaced, too. “It’s not as common as cataract surgery, but many people get corneal diseases after age 50 and may need a corneal transplant,” says Dr. Nandini Venkateswaran, a corneal and cataract surgeon at Harvard-affiliated Massachusetts Eye and Ear.

More than 49,000 corneal transplants occurred in 2021 in the US, according to the Eye Bank Association of America.

What is the cornea?

The cornea is a dome of clear tissue at the front of each eye, covering the iris and pupil, that acts as a windshield that protects the delicate eye apparatus behind it, and focuses light onto the retina, which sends signals that the brain turns into images (your vision).

You need this combo of windshield and camera lens to focus and see clearly. But many things can go wrong within the five layers of tissue that make up the cornea. That can make it hard to see and rob you of the ability to read, drive, work, and get through other activities in your day.

How does damage to the cornea occur?

It may stem from a number of causes:

• Injuries, such as a fall. “Falls are a big reason for people to come in with acute eye trauma. The cornea can be damaged easily if something pokes it,” Dr. Venkateswaran says.
• Previous eye surgeries. “Especially for adults who’ve had several eye surgeries — such as cataract and glaucoma surgeries — the inner layers of the cornea can become damaged and weakened with age,” she adds.
• Illness. Problems like severe corneal infections, or genetic conditions such as Fuchs’ endothelial dystrophy, can cause vision loss.

What are the options for treating corneal damage?

Cornea treatment depends on the type of problem you have and the extent of the damage. “It’s a stepwise approach. Sometimes wearing a specialty contact lens or using medications can decrease swelling or scarring in the cornea,” Dr. Venkateswaran says.

When damage can’t be repaired, surgeons can replace one or a few layers of the cornea (a partial-thickness transplant), or the whole thing (a full-thickness transplant).

The vast majority of transplants come from donor corneas that are obtained and processed by eye banks throughout the US. In some instances, such as when repeated transplants fail, an artificial cornea is an option. Recovery after corneal surgery can take up to a year.

How long-lasting are corneal transplants?

There’s always a risk that your body will reject a corneal transplant. It happens about a third of the time for full-thickness transplants. It occurs less often for partial-thickness transplants. Preventing rejection requires a lifetime of eye drops.

Still, transplant longevity varies. “I’ve seen transplants from 50 or 60 years ago and now they’re starting to show wear and tear. Other patients, for a variety of reasons — immune system attacks, intolerance to eye drops, or underlying conditions — may only have a transplant for five to 10 years before they need another,” Dr. Venkateswaran explains.

Preventive eye care can help preserve the cornea

It’s crucial to get regular comprehensive eye exams to make sure your corneas and the rest of your eyes are healthy.

The American Academy of Ophthalmology recommends a comprehensive (dilated) eye exam

• at age 40
• every two to four years for people ages 40 to 54
• every one to three years for people ages 55 to 64
• every one to two years for people ages 65 and older.

You’ll need an eye exam more often if you have underlying conditions that increase your risk for eye disease, such as diabetes or a family history of corneal disease.

If you have any vision problems, such as eye pain, redness, blurred vision despite new glasses, or failing eyesight, see an eye doctor.

Fortunately, for people who do experience corneal damage, advances in surgical options are encouraging.

“Corneal transplants are a miracle,” Dr. Venkateswaran says. “I have patients whose quality of life was significantly decreased because they couldn’t see through their cloudy windshield. We can give them sight again, and we have the technology and medications to keep the transplant alive.”

About the Author

Heidi Godman, Executive Editor, Harvard Health Letter

Heidi Godman is the executive editor of the Harvard Health Letter. Before coming to the Health Letter, she was an award-winning television news anchor and medical reporter for 25 years. Heidi was named a journalism fellow … See Full Bio View all posts by Heidi Godman

Active surveillance for prostate cancer has its tradeoffs. Available to men with low- and intermediate-risk prostate cancer, the process entails monitoring a man’s tumor with periodic biopsies and prostate-specific antigen (PSA) tests, and treating only when — or if — the disease shows signs of progression.

Active surveillance allows men to avoid (at least for a while) the side effects of invasive therapies such as surgery or radiation, but men often feel anxious wondering about the state of their cancer as they spend more time untreated. Is there a middle path between not treating the cancer at all and aggressive therapies that might have lasting side effects? Emerging evidence suggests the answer might be yes.

During a newly-published phase 2 clinical trial, researchers evaluated whether a drug called enzalutamide might delay cancer progression among men on active surveillance. Enzalutamide interferes with testosterone, a hormone that drives prostate tumors to grow and spread. Unlike other therapies that block synthesis of the hormone, enzalutamide prevents testosterone from interacting with its cellular receptor.

A total of 227 men were enrolled in the study. The investigators randomized half of them to a year of daily enzalutamide treatment plus active surveillance, and the other half to active surveillance only. After approximately two years of follow-up, the investigators compared findings from the two groups.

The results showed benefits from enzalutamide treatment. Specifically, tumor biopsies revealed evidence of cancer progression in 32 of the treated men, compared to 42 men who did not get the drug. The odds of finding no cancer in at least some biopsy samples were 3.5 times higher in the enzalutamide-treated men. And it took six months longer for PSA levels to rise (suggesting the cancer is growing) in the treated men, compared to men who stayed on active surveillance only.

Enzalutamide was generally well tolerated. The most common side effects were fatigue and breast enlargement, both of which are reversible when men go off treatment.

In an accompanying editorial, Susan Halabi, a statistician who specializes in prostate cancer at Duke University, described the data as encouraging. But Halabi also sounded a cautionary note. Importantly, differences between the two groups were evident only during the first year of follow-up. By the end of the second year, signs of progression in the treated and untreated groups “tended to be very similar,” she wrote, suggesting that enzalutamide is beneficial only for as long as men stay on the drug. Longer studies lasting a decade or more, Halabi added, may be necessary to determine if early enzalutamide therapy changes the course of the disease, such that the need for more invasive treatments among some men can be delayed or prevented.

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, editor of the Harvard Health Publishing Annual Report on Prostate Diseases, and editor in chief of HarvardProstateKnowledge.org, said the study points to a new way of approaching active surveillance, either with enzalutamide or perhaps other drugs. “An option that further decreases the likelihood that men on active surveillance will need radiation or surgery is important to consider,” he says. “This was a pilot study, and now we need longer-term research.”

About the Author

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

No one is truly allergic to the sun, but some people are quite sensitive to different types of sun rays and may develop mild to serious reactions after spending time in the sun.

There are several types of “sun allergies,” but polymorphous light eruption (PMLE), an autoimmune condition in the skin that occurs after sun exposure, is one of the most common. Other conditions considered as sun allergies are solar urticaria (hives and reddish patches that usually start 30 minutes to two hours after the sun exposure), actinic prurigo (papules and nodules that are intensely itchy on sun-exposed skin areas), and photoallergic reaction (when the UV rays from the sun modify the chemical structure of medications or products applied to the skin, and a person develops an allergy to the newly modified substance).

What causes PMLE?

People who have PMLE have immune cells that are triggered by sun rays, which attack their skin, and they develop a skin reaction to the sun’s the ultraviolet (UV) rays.

PMLE represents 70% of all sun-induced skin eruptions. It can affect both sexes and all skin types, and it usually starts when someone is a teen or young adult. PMLE may be an inherited condition. Being a female, having fair skin, and living in the north are other risk factors.

PMLE is more common in young women who live in temperate climates. People who live in temperate climates spend all winter out of the sun, so when it becomes warmer the sun exposure is intense. People who live in warmer climates are desensitized because they have a higher sun exposure all year.

What does PMLE look like?

PMLE can appear several hours or days after the first major sunlight exposure of the season, usually during spring or at the beginning of summer. The areas of the body generally affected the most are the ones that are covered during wintertime, but not in the summer: the neck, the chest, and the outer parts of the arms.

After exposure to the sun, people with PMLE usually notice reddish patches on their skin. These spots may itch, burn, or sting, but they typically don’t leave a scar. In more severe cases, the patches cover most of the body and may also be associated with headaches, fevers, tiredness, and low blood pressure. (If you experience these symptoms, see an urgent care provider for evaluation.) If you think you have PMLE or another sun allergy, a dermatologist is the best doctor to evaluate and treat your skin condition.

Does PMLE get better?

PMLE lesions often get better in approximately 10 days, and it’s important to avoid sun exposure until you are healed. People who develop PMLE can experience significant discomfort and have their life negatively impacted during the spring and summer months. However, repetitive sun exposure can make PMLE less likely to occur. The hardening effect, as it is called, means that the skin lesions that appear after the first episode are less severe, and they can be better tolerated during subsequent episodes.

What are current treatments for any sun allergy, including PMLE?

The best treatment is to prevent sun exposure. Avoid sunlight when it is most intense (from 10 a.m. to 4 p.m.), and use UV-protecting clothing or clothes made of darker and thicker fabrics, as they will prevent the UV rays coming from the sun from reaching your skin. Hats with a wide brim protect your scalp, face, and (partially) the neck.

Broad-spectrum sunscreens that protect your skin from both UVA and UVB rays should be used daily, even if it’s cloudy. Apply sunscreen on your face and any part of your skin that is not covered by a hat or clothing. Reapply sunscreen every two hours, and if you go swimming or get sweaty reapply more frequently (water-resistant sunscreen should also be reapplied).

If you develop PMLE, the areas of skin impacted can be treated with steroid creams. In severe cases, your doctor may recommend a short course of steroid pills. Medications that reduce the immune response, such as azathioprine, are options for treating PMLE, since it is an autoimmune condition (the body is attacking it is own healthy cells).

Antihistamines are medications typically used for allergies that may help shorten the duration of reddish patches that itch or burn, and they also reduce inflammation.

Hydroxychloroquine (a medication also used to treat malaria) can be used in case of flare-ups, or as a prevention method when people travel to sunny locations during winter vacations.

Oral Polypodium leucotomos extract, a natural substance derived from tropical fern leaves, may work as a potent antioxidant, and has anti-inflammatory properties that are beneficial in the prevention of PMLE. Other nutritional supplements containing lycopene and beta-carotene (vitamin A derivatives) have a similar effect. A dermatologist will guide you on the best way to use these medications.

The bottom line

Sun allergies are common in temperate climates, but with a dermatologist’s guidance, vigilant sun prevention, and medications they can be managed throughout the sunny months of the year.

About the Authors

Neera Nathan, MD, MSHS, Contributor

Dr. Neera Nathan is a dermatologist and researcher at Massachusetts General Hospital and Lahey Hospital and Medical Center. Her clinical and research interests include dermatologic surgery, cosmetic dermatology, and laser medicine. She is part of the … See Full Bio View all posts by Neera Nathan, MD, MSHS

Lais Lopes Almeida Gomes, Contributor

Dr. Lais Lopes Almeida Gomes is a dermatology research fellow at Massachusetts General Hospital, and a pediatric dermatologist in Brazil. Her clinical and research interests include atopic dermatitis and global health. She is part of the … See Full Bio View all posts by Lais Lopes Almeida Gomes