Doc, I've got a question

I believe the chart you are referring to is the BMI calculator, which stands for body mass index. It was first thought up by Adolphe Quetelet, a Belgian astronomer and mathematician who lived in the mid 1800s. The current formula was published in 1972 by Ancel Keys in the Journal of Chronic Diseases.  In other words, it is a number that compares your weight for your given height. Different medical, statistical, and public health groups have argued about what the standard measures should be, but currently the medical community uses these values for adults: Underweight equals  less than 18.5, Normal weight equals 18.5–24.9 Overweight equals 25–29.9, Obesity equals BMI of 30 or greater.

As you mentioned, there are flaws in this calculation. Most important, it does not differentiate weight from muscle vs fat or bones. So, it is a measure of excess weight versus excess fat, although those usually go hand in hand. Factors such as age, sex, ethnicity and muscle mass can influence the association between BMI and body fat. Older individuals usually have more fat and less muscle mass than a younger person with the same weight. Women tend to have more body fat for the same BMI compared to males. Muscular people, or highly trained athletes have higher BMI due to high muscle mass. There is also a debate on how height should be scaled in the calculation. Currently, very short people may have their BMI be too low, and a tall person may have a higher BMI than appropriate. For example, Clay Matthews is an NFL linebacker, who is listed as 6’3",  255 pounds. This gives him a BMI of 31.9. I would certainly not describe Clay Matthews as obese, particularly to his face. No offense to you or other readers, but most of us do not look like Clay Matthews and do not have large enough muscle mass to drastically throw off our BMI. BMI works well for population analysis of weight and body fat, but admittedly works less well for an individual. BMI works as a first screening tool, but is not diagnostic for excess body fat on its own. If your doctor is concerned about your weight, there are other more specific tests that measure body fat percentage. In general, higher BMI usually correlates with higher body fat percentage, which studies link with increased risk for heart disease, diabetes, high blood pressure, arthritis, sleep apnea, strokes, gallbladder disease and several types of cancer. I would recommend discussing with your weight with your doctor and find out what concerns he/she has.

I have a friend who has an Epi-Pen. She says I have to use it on her if she ever needs it. I’m scared. What do I do? Can I screw it up?

Epi-Pen is a device that delivers a specific dose of epinephrine to a patient who is undergoing a severe allergic reaction, referred to as anaphylaxis. Signs of anaphylaxis including rapid onset rash, skin redness, throat or tongue swelling, vomiting, dizziness or low blood pressure. This reaction can be life threatening, and requires immediate action. Autoinjectors like the Epi-Pen are set up to give a specific dose that is already in the unit. You do not have to use a needle to draw up the medication into a syringe. To use an Epi-Pen, you remove it from its container, then remove the safety cap, which is blue on the Epi-Pen. Position the needle end, which is orange, a few inches away from the outer part of the thigh, and jab the orange end into the thigh, through any clothing present. It will make an audible click sound to let you know it activated. Hold in place for a slow three-second count, then remove from the leg and massage site of injection for roughly 10 seconds. The needle will automatically move back into the unit. At this point it is important to either call 911 or to take your friend to the emergency room for further evaluation. A second dose, using a second Epi-Pen, can be given 5-15 minutes after the first, if symptoms persist. There are other brands of epinephrine auto-injectors that may have slight differences in their use. The main principles are the same however: the dose is ready to go, aim for the outer thigh and hold in place for at least three seconds before removing. Auto-injectors are designed to go through clothing, including jeans.

The most important thing is to ask you friend what her specific allergies are, as well as what her reaction tends to be or look like. Ask your friend to show you the unit she has and walk you through its use in person. Her doctor’s office or pharmacy may be able to get practice pens without medication that you could practice with to become more comfortable. With the Epi-Pen, you cannot give the wrong dose if used correctly, and you can never give more medication than it is set up for. As long as you give the dose in the outer thigh and hold for three seconds, it is almost impossible to use it incorrectly. And I want to reemphasize, once the dose has been given please seek emergency medical attention, either by taking your friend to the ER or calling 911.

How damaging are seasonal allergies? I know certain plants make me sneeze. But after their season is over, I’m fine. Do I need to take anything for this?

Seasonal allergies, like other allergies, are due to an immune reaction caused by exposure to a substance our body is sensitive to. This causes a release of histamine from immune cells, which causes constriction of the smooth muscle of our GI tract and airways, enhanced permeability of blood vessels, increased mucus production, itching, and dilation of blood vessels in the skin. This causes the characteristic symptoms people with allergies experience, including sneezing, itching, watery and red eyes, trouble breathing and coughing. These symptoms can be miserable for many. Allergies affect anywhere from 10--to-30 percent of Americans. Seasonal allergies are usually caused by pollen from trees, grasses and weeds. Luckily, these often improve after the season.

While certain allergic reactions can be life-threatening, most seasonal outdoor allergies are less troublesome. They can cause trouble with sleep, difficulty with taste or smell, increased chance of migraines and nasal obstruction. If your symptoms don’t bother you that much, you do not have to take anything. But there are several over the counter anti-histamines available that can be quite beneficial for symptom control. These include loratidine (Claritin), cetirizine (Zyrtec), fexofenadine (Allegra), and desloratadine (Clarinex). All of these meds work and do not tend to cause much drowsiness. Some people will have a better response with one medication vs the others. Benadryl (diphenhydramine) is another anti-histamine that works very well, but tends to cause more drowsiness than the others. If you do not get good relief with one medication, I would try switching to another to see if it works better for you. If you still do not get relief, consult your physician.

When are you not contagious? I have a co-worker who said she had the flu all weekend. She came into work on Monday and said, “Don’t worry. I’m not contagious.” Should I have exercised concern?

Unfortunately, there is no one answer to the question of how long a person is contagious after contracting an infectious illness. People with simple viral upper respiratory illnesses can remain infectious for several days.

Generally speaking it is always best to exercise caution when you are around people who are or have been sick in the last several days. If possible, anyone who is sick should stay home from work. This is especially important if he/she has a fever. The easiest and best ways to reduce transmission of microbes like viruses and bacteria include: frequent hand washing, covering your mouth and nose when you cough or sneeze, avoiding close contact with sick people, and avoiding touching your eyes, mouth and nose. Use a cleaner to wipe down your work space, paying particular attention to things you touch the most, including cell phones, keyboards and mouses. Also, it is important to get your yearly flu shot to help reduce your chance of catching or spreading influenza.

Ideally, people would wait until they don’t have symptoms before returning to work, however this isn’t feasible for most. A general rule of thumb, anyone with a fever needs to stay home. You may return to work after going 24 hours without a fever and not using anti-fever medications like Tylenol or ibuprofen. If your doctor put you on antibiotics for an infection, in addition to following the fever guideline, it is best to wait until 24 hours after starting the antibiotic before returning to work. The best way to reduce transmission is the simple things listed earlier, especially frequent hand washing!

What kind of damage can the sun do to your eyes? Are cheap sunglasses just as protective as the expensive ones?

The sun gives off a type of light known as UV light. This type of light is what can cause skin cancers like melanoma. At the same time, it can cause damage to yours eyes as well, including increasing your risk for cataracts, growths on the eye called pterygium, keratitis (corneal sunburn), and multiple types of eye cancer as well as skin cancer on the eyelids. Because of these risks, it is important to protect your eyes just as you protect your skin from the sun’s rays with sunscreen. The American Academy of Ophthalmology (AAO) has several recommendations to protect your eyes: 1. Wear sunglasses all year, not just in the summer. 2. The sun can still cause damage on a cloudy day. 3. Sunlight is strongest mid-day to early afternoon, at higher altitudes, and when reflected off of water, ice or snow. 4. Wear a hat as well, broad-brimmed are best. 5. Don’t forget your kids! Their eyes are just as vulnerable.

The AAO also has recommendations on what sunglasses to buy, and luckily it has nothing to do with price! The AAO recommends buying sunglasses that state “100 percent UV protection.” They are listed as blocking both UV-A and UV-B light, and are labeled as UV-400 or 100 percent UV protection. Bigger sunglasses that cover more of your face protect better. Wraparound styles help cut down on light entering from the sides. The color of the lens make no difference as long as they provide 100 percent UV protection, dark lenses do not necessarily work better. Polarized lenses help cut glare, which you may find beneficial, but do not increase protection to your eyes. You can find plenty of cheap sunglasses that meet the recommended 100% UV protection. More expensive sunglasses do not provide any protection that you cannot find in cheaper offerings. So make sure you are looking at the protection before you buy, wear a hat, and don’t forget the kids and you will keep your eyes happy and healthy!