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Even in food families: we get along with some relatives better than others

Even in food families: we get along with some relatives better than others

Food families have similar proteins and this can lead to cross-reactive allergy. That having been said, not all families have the same degree of cross-reactivity.

Peanut allergy is often severe but, luckily, has one of the lowest levels of cross-reactivity with other legumes. There is only a 5 percent risk of cross-reactivity for peanut with beans, peas and soybeans.

Cow-milk allergy is the highest (at 90 percent), with other mammals and milks from sheep and goat. Yet, people with cow-milk allergy almost never react to mare’s milk, donkey’s milk or dolphin’s milk.

Shellfish cross-reactivity is high at 75 percent. Thus if an individual is allergic to shrimp, he or she has a three in four chance of also being allergic to lobster, crabs or crawfish. This high degree of cross-reactivity is not true for non-crustacean shellfish such as clams and oysters.

Fish cross-reactivity is roughly 50 percent.

Tree nut allergy is about 35 percent cross-reactive across the board. However, certain nuts seem more closely linked. Pistachio is very similar to cashew, walnut to pecan and almond to hazelnut. Nut allergy does not translate to seed allergy such as sesame seed, but sesame, poppy and sunflower tend to be cross-reactive with one another.

On a practical level, if an individual with a specific food allergy has already tolerated other foods in the same family, that person should continue to be safe in eating these family-related foods. Still, foods in the same family that have not yet been tried should be considered suspect, and the individual may want to undergo allergy testing to determine the safety of the particular food.

Add one to the OK list for coffee and tea drinkers

Add one to the OK list for coffee and tea drinkers

 Coffee and tea have long been known to have antimicrobial benefit. Because of this knowledge, researchers at the Medical University of South Carolina decided to study whether drinking these beverages impacted the carrier rate of methicillin-resistant Staphylococcus aureus, the multi-drug-resistant staph infection known as MRSA.

An estimated 3-million Americans are carriers of MRSA. This represents almost two percent of the population. By monitoring nasal swab cultures, the university scientists were able to demonstrate a 50 percent reduction in carrier state of MRSA in individuals who drink coffee and or tea. No reduction in carrier state was seen in people who drink sodas, even if they contain caffeine.

For millions of asthmatics, hopeful gene therapy studies

For millions of asthmatics, hopeful gene therapy studies

The lead article in The New England Journal of Medicine in September discussed novel research on genetic variation in asthma. More than 300-million people worldwide have asthma, and up to 20 percent of these show poor or no response to corticosteroid medication, which is usually their main controller medicine.

Researchers at Harvard speculated this lack of response to corticosteroid medicines might be genetically linked and they sought to find the gene.

By screening 530,000 single-nucleotide polymorphisms (SNPs – pronounced snips) in a large group of asthmatics they discovered one SNP called rs37973 that showed up in the non-steroid responders. Furthermore, they discovered that rs37973 decreases the effectiveness of gene GLCCI-1, which is the gene that controls response to steroids.

Their hope is that new therapies will soon be discovered that “up-regulate” (turn on) the depressed GLCCI-1 gene.

Instrument allergies can sour the sound

Instrument allergies can sour the sound

 Musicians can present a unique group of skin rashes related to their profession or avocation. Some of these rashes are so common they have characteristic names such as fiddler’s neck, flautist’s chin, guitarist’s nipple and harpist’s finger.

In a recent survey, 21 percent of musicians reported some type of instrument-related rash. Some of these rashes are mechanical in nature, such as chaffing, erosions or blistering and callusing due to repeated trauma.

Many of the rashes are allergic in origin and the common causes are exotic woods, metals, resins, stains and varnishes. The most common allergic metals used in instruments are chromium, cobalt and nickel. Many wind instrument users develop skin or lip rashes from their instruments.

Woods that have a high allergic potential are ebony, cocobolo, African Blackwood, Brazilian and Indian rosewood. Also, cane reed used in mouthpieces can cause allergic problems.

Paraphenylendiamine is a black dye that causes allergy and is commonly found in stringed bows and chin rests. Propol is also known as bee glue and is used in violin varnish and is a strong allergen. Colophony – a solid form of resin obtained from pines and some other plants, mostly conifers – is also a significant allergen for violinists, violists and cellists.

The metals that cause allergy are not only found in wind instruments (brass), but also in string instruments – especially guitars, cellos, violins, sitars and harps.

The key (pun intended) to diagnosing the cause of these rashes is that they occur in the specific body parts that touch the instrument.

Kiwi fruit a mix of tasty, pesky and protective

Kiwi fruit a mix of tasty, pesky and protective

 Kiwi fruit is a source of increasing allergic problems. The kiwi first became commercially available in the U.S. in 1970 and has led to a variety of allergic problems. The most common issue is oral allergy syndrome which consists of itching, burning and swelling of the lips, mouth, tongue and throat. Although not of life-threatening consequences, the symptoms are quite disturbing.

Much less frequent is anaphylactic allergy which is truly serious in nature. Of curious interest, most people with kiwi allergy are also allergic to birch pollen and in many cases to latex. Other allergens that commonly cross-react with kiwi are figs, avocado, banana, melon, hazelnut, rye, wheat and pollen from Timothy grass, mugwort and olive tree. Kiwi is native to southern China and is the Chinese national fruit. Seeds were introduced to New Zealand in 1940 and from there spread to Italy, Chile and the U.S.

Skin allergy is also seen from contact with the fruit or the vines, the main allergens in the kiwi are an enzyme called actinidin and a protein called kiwellin. The skin allergy is similar to poison ivy in that the rash appears one to three days after the contact.

Despite the mischief it can cause, kiwi has a lot of health value. It is a very rich source of antioxidant free radical scavengers, and thus, can reduce risks of cancer and cardiovascular disease. Kiwi extract has also been used in treating serious burns.

Vaccines after 65 — who and what for?

Vaccines after 65 — who and what for?

Dear Dr. K: I recently heard that there are certain vaccines that are recommended for adults. I thought I got all my necessary vaccines as a kid.

Not to pick on you, but I can tell by your question you didn’t read last month’s newsletter. In that issue I discussed influenzal vaccine (flu shot) which is recommended on a yearly basis. The vaccine is given yearly because it is a different shot each year, in order to address the new viral strains that emerge.

The tetanus/diphtheria (TD) vaccine is needed every 10 years throughout life. A new spin on this recommendation is that once during adulthood the TD should include pertussis (TDap).  The “ap” stands for acellular-pertussis, which is the new, improved whooping cough vaccine. This new recommendation reflects a resurgence of whooping cough illness in adults, due to waning immunity from our childhood vaccine.

Pneumococcal vaccine (pneumonia shot) can be taken by all adults, but is felt to be essential for persons with respiratory disease (COPD and asthma), heart disease, kidney disease, liver problems, diabetes, HIV and asplenic patients (persons who have lost their spleen). If the first vaccine is given before age 65, then a second vaccine is recommended after five years. If the initial vaccine is given after age 65, then no further shot is needed.

Herpes zoster (shingles) vaccine is recommended for all adults 60 years or older. Even if a person has already had shingles, the vaccine is still recommended.

Meningococcal vaccine (meningitis) is recommended for all young adults attending college. It is also recommended for mature adults with asplenia, HIV; and those who travel to endemic areas and for military personnel.

Hepatitis A vaccine is recommended for travel exposure, gay men, people with liver disease, and people with daycare exposure.

Hepatitis B vaccine is recommended for gay men and for heterosexual people who are not in a monogamous relationship. It is also recognized for all healthcare workers and for public safety personnel and for family members of patients who have chronic hepatitis B infection.

New asthma medicine: A hopeful mouthful

New asthma medicine: A hopeful mouthful

The September issue of the New England Journal of Medicine discussed research on the newest medicine for asthma, Lebrikizumab. This drug is an IgG4 humanized monoclonal antibody that binds to interleukin-13 (I-13).

I-13 is a cytokine (cell communicator) that plays a big role in causing the inflammation of asthma. It does this in part by causing airway cells to produce periostin, which causes narrowing and thickening of the airways.

Inhaled steroids are supposed to inhibit I-13, but they don’t always accomplish the task. In a study of 219 moderate and severe asthmatics there was dramatic improvement in lung function (measured by breathing tests). Of special note, this improvement was almost immediate with starting the medicine.

The people who improved the most were the ones with the highest periostin levels.

Lebrikizumab is still undergoing clinical trials but hopefully, will soon be approved by the FDA. If the FDA gives a thumbs up, let’s cross our finger they’ll mandate a simpler name for the drug!

Quick Tips – Dental work

Quick Tips – Dental work

•               In 2007, the widespread policy of antibiotic prophylaxis before dental procedures was challenged by an international group of academic cardiologists. The UK instituted this new approach in 2007 and just completed a four-year outcome study. They have found no increase in infective endocarditis despite cessation of pre-dental antibiotics. They do, however, still recommend antibiotics for people with congenital heart disease and artificial heart valves.