Sep
23
2023

Allergies to Red Meat after a Tick Bite

By | Allergies, anaphylactic reaction, food, Prevention, red meat

A new disease has arrived, allergies to red meat after a tick bite. This condition has surfaced in Australia and in the southeast of the US. It is linked to the bite by a lone star tick. Researchers determined that alpha-gal, which is galactose-α-1,3-galactose from the saliva of the tick is responsible for causing an allergy. Meat from mammals also contains alpha-gal. Due to a cross reaction between a lone star tick bite and alpha-gal in beef and other meats a person can develop a sensitivity to alpha-gal. This has the name alpha-gal syndrome (AGS). Between 2010 and 2022 the CDC recorded about 110,000 suspected cases of AGS in the US.

Symptoms of alpha-gal syndrome

A person who was previously sensitized by a lone star tick bite often only gets symptomatic after eating beef. The symptoms are hives, a skin rash, nausea or vomiting, heartburn or indigestion and diarrhea. Other symptoms could be a cough, shortness of breath, difficulty breathing or a drop in blood pressure. Some patients develop swelling of the lips, throat, tongue, or eye lids. Others complain of dizziness, faintness or severe stomach pains. These symptoms usually develop 2 to 6 hours after eating a meal with beef or dairy products. The person who was previously bitten by a lone star tick was sensitized following this encounter and produced specific antibodies against alpha-gal. The second encounter of the body from ingested alpha-gal containing food is the reason why the allergic reaction takes place. The more alpha-gal is ingested by different foods that contain it, the more severe the allergic reaction becomes.

Diagnostic tests for alpha-gal sensitivity

Allergists have the following tests available to them to check your immune system.

  • One test is called the alpha-gal U953 immunocap, a blood test.
  • The mammalian meats immunocap (Beef, Lamb, Mutton, Pork and Rabbit are available) shows specific antibodies as a result of exposure to these meats.
  • In severe cases of alpha-gal sensitivity blood tests for a mast cell tryptase level may also be necessary. This test can distinguish between a higher or lower risk of alpha-gel sensitivity. Tryptase is an enzyme, which is higher in people with mastocytosis. There is often an elevation of tryptase in patients who have allergies to both insect bites and tick bites.

Foods that contain alpha-gal

The Australasian Society of Clinical Immunology and Allergy describes in great detail what foods contain alpha-gal and what not. The main culprit in developing alpha-gal syndrome is mammalian meat. The most popular among these is beef, but veal, pork, lamb, buffalo, venison, rabbit and guinea pig also belong into this category. Other meats are deli meats like bacon, ham, salami, silverside, chorizo, prosciutto and others. When a person reacts to eating one or more of these items, we are dealing with a cross reaction. It is between the alpha-gal from the original tick bite and alpha-gal from the meat the person ingested.

There are more obscure mammalian meats that contain alpha-gal: whale, dolphin, seal, goat, kangaroo, wallaby and possum. But gelatin products and fats from mammals also contain alpha-gal.

What foods do not contain alpha-gal?

The following foods are OK to eat for people with alpha-gal sensitivity: chicken, mollusks, crustaceans, turkey, quail, goose, fish, duck, eggs, legumes, lentils and soy products (tofu, tempeh). According to the allergy.org website, you have to be careful about jams, soups and gravies, as merchants often mix gelatines into their products. Stay away from energy drinks with taurine, sausages (even chicken sausage) and cheese spread. Avoid rennet, jelly-based lollies, mousses and desserts. All of them contain alpha-gal.

Treatment for alpha-gal syndrome

There is no known treatment for sensitivity to alpha-gal. However, experience has taught allergists that strict avoidance of alpha-gal in food improves the symptoms. After about 3 to 4 years of a strict diet that excludes alpha-gal many patients are no longer sensitive to alpha-gal and can tolerate a certain amount of alpha-gal in their diet. But others continue to be sensitive to alpha-gal. They have to adhere to strict avoidance of alpha-gal in food and stay away from tick bites.

Allergies to Red Meat after a Tick Bite

Allergies to Red Meat after a Tick Bite

Conclusion

A new condition, alpha-gal syndrome has joined the rare, but important group of new diseases. It is a sensitivity to a sugar, called galactose-α-1,3-galactose, or alpha-gal. It is present in the mouth and saliva of the lone-star tick in the US and Australia. A bite from this tick can be the first sensitizer in a human. But unfortunately, alpha-gal is also present in many foods as mentioned in detail above. Repeated exposure to alpha-gal regardless of the origin causes hypersensitivity, which can get life-threatening. There is no treatment for this condition other than to adopt a very meticulous avoidance of alpha-gal in the diet. After 3 to 4 years of such a diet the hypersensitivity to alpha-gel disappears in many, but not in all patients. When the hypersensitivity persists, the patient has to continue with the alpha-gal avoidance diet.

Jul
02
2016

Zika Virus

By | immune system, Infectious Disease, Other neurological conditions

Recently the question was asked on the news whether it was safe to go to the Olympics in Brazil; so here is some background information about the Zika virus. Zika virus was first isolated from mosquitoes in a forest named Zika forest in Uganda, which was in 1947.

Zika virus belongs into the virus family of Flaviviridae. Other members in that family are dengue fever, West Nile virus, yellow fever and Japanese encephalitis. Since the 1950’s Zika virus has occupied a narrow equatorial belt around the globe (Africa and Asia). But between 2007 and 2016 it spread further to the Americas and to the Pacific. This includes specifically French Polynesia, the Cook Islands, Easter Island and New Caledonia. Since May 2015 Brazil has joined the countries where mosquitoes are infected with Zika virus. This is an important point to know for the coming up Olympics in Rio on August 5 to 21, 2016.

Symptoms of Zika virus

For most people, particularly the young and middle aged ones Zika is  not be that symptomatic. The most common symptoms are a fever, a skin rash, joint aches and red eyes (conjunctivitis). However, when a pregnant woman gets Zika virus, this will likely affect the fetus and will lead to a baby born with a small head (microcephalus), a severe complication from Zika virus. When a woman contracts Zika virus, the virus disappears after about one week. But in men the virus seems to stay longer, particularly in semen. This is why the CDC recommends for men using a condom or refraining from sex when returning from a holiday in a Zika endemic area. It may take up to 8 weeks for the semen to no longer be infective. The CDC recommends that a man who has come down with Zika to use a condom for 6 months.

Treatment of Zika virus

Make sure you get lots of rest. Take acetaminophen for fever or pain. Don’t take aspirin (ASA) or anti-inflammatory medication. Be aware that for between 1 and 3 weeks your blood likely is infectious. You want to avoid a bit from a mosquito and it is sensible to use insect repellants. The same insect could have bitten another person and spread the virus this way. A person who gets the Zika virus depends on the immune system to overcome the infection as there is no cure for this viral infection.

At this point no vaccine against Zika exists. There is research in an attempt to develop a Zika vaccine, which may become available in 2 to 3 years.

Zika virus risk with travel

If you travel to endemic areas, but visit mountainous areas above an elevation of 6,500 feet (2,000 meters) you are safe from Zika transmitting mosquitoes as they do not survive in these heights.

With regard to the Olympic Summer Games in Rio 2016 the CDC recommends to take a few precautions. Use insect repellents. Be aware as a woman that men infected with Zika virus can transmit the virus through sex. If you want to protect yourself from the risk of giving birth to a child with microcephaly, you may decide to use the birth control pill and ask your partner to use a condom. When you return back home, do not plan for a pregnancy for 6 months to avoid the risk.

The only recommendation for the Olympics by the CDC is that pregnant women should categorically not go to the games for fear of getting Zika infection resulting in a bad outcome of the pregnancy with microcephaly.

Microcephaly and other brain abnormalities from Zika virus

The CDC has stated that it is now established that Zika virus can cause microcephaly, but that it likely does not do so in all cases of Zika virus infection.

We know from German measles (rubella) that it can cause serious health risks for the fetus including death.

Zika is similarly neurotropic, meaning that it likes to multiply in nervous tissue including the brain. With rubella there is a vaccine available, which has made it much safer for pregnant women. But with Zika no vaccine is available. The only prevention is to stay away from endemic Zika areas and otherwise use reliable birth control methods.

Zika Virus

Zika Virus

Conclusion

I have briefly reviewed Zika virus in this blog. Unfortunately there are still many gaps in the knowledge of this disease. We need an effective Zika virus vaccine. It would also help to have antiviral antibiotics. Research is necessary to research all of this. For now we need to use prevention and avoid endemic Zika regions by reading updates by the CDC.

Sep
01
2005

Getting Ready For Ragweed Allergies Is Important

By | Allergies, Asthma, Eye Diseases

Allergies are often associated with watery eyes and sneezing, and in commercials that promote over-the counter anti-allergy pills (antihistamines) the effects are shown as merely bothersome. The commercials are often amusing. The facts for the allergy sufferer are neither amusing nor are allergies a minor bother. They have to be taken serious, as they can affect the quality of life and even be potentially life threatening. A very common plant that can be the culprit for serious allergies is ragweed. Two varieties of the plant are accounting for the worst problems, Ambrosia trifida and Ambrosia artemisiifolia. People who are sensitized to the pollen of ragweed have the most severe symptoms in the months of August to October. Nasal congestion, sneezing, a constantly runny nose and itchiness of eyes, nose and throat are the problems that are encountered by the patient, but asthma can be the more serious consequence. The quality of life in the peak season of ragweed shows significant deterioration for allergy sufferers, as nasal congestion alone is linked to poor sleep quality which in turn leads to decreased productivity at work or in school. A skin rash can be another form of an allergic reaction. It is the less common form of ragweed allergy, but left untreated it becomes chronic and progressively worse. Other herbal products (chamomile and arnica), which may be used as compresses and as an ontment, can cross-react with ragweed exposure and produce a skin rash or dermatitis. Adults are more affected than children, and people with outdoor occupation (farmers, gardeners, harvesters, carpenters) are the group most at risk. Unfortunately, ragweed particles are very small and very light, which makes it very difficult to avoid them in the peak season, but there are measures one can take to avoid exposure.

Getting Ready For Ragweed Allergies Is Important

Getting Ready For Ragweed Allergies Is Important

The peak time of pollen exposure is in the middle of the day, and it is a good idea to keep the windows closed to prevent large amounts of pollen from drifting into your home. The use of an air conditioner in the car or at home can be helpful. After spending time outdoors it can be helpful to change into fresh clothes and perhaps even take a shower. Drying clothes on the laundry line in peak season should be avoided, as they are prone to collect large amounts of pollen.

Getting Ready For Ragweed Allergies Is Important1

Ragweed Blossoms Late In The Season

Timing vacations to leave ragweed-infested areas for other parts of the country can also help. It is also important to take action as soon as symptoms are present. Letting things take their course, will just have a snowball effect. An allergist can do patch tests to determine whether there is a reaction to ragweed. If ragweed dermatitis is present, it has to be treated early on to avoid the difficult to treat chronic state, in which a lower UV threshold is also part of the condition. Decongestants may help with nasal congestion, but unfortunately they tend to cause side effects, such as sleeplessness and a rapid heart beat. The physician can point out the most effective antihistamine to the patient, and intranasal cortico steroids (INCS) may be preferable over oral antihistamines. Newer INCS medications have shown to provide quick control of nasal symptoms, and they can actually minimize the emergence of symptoms, if they are started before the ragweed season begins in mid summer.

More info about asthma: http://nethealthbook.com/lung-disease/asthma-introduction/

Reference: Allergy & Asthma, Summer 2005, page 4-9, page 13-16

Last edited October 29, 2014