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Month: August 2020

Jellyfish Allergy

Jellyfish Allergy

Floridians need to be aware that jellyfish can not only be a source of an unpleasant sting, but also of allergic reactions.   In fact, life threatening allergy (anaphylaxis) was first described in 1901 by two scientists; Charles Richet and Paul Portier who were studying jellyfish.  They began their studies at the behest of Prince Albert of Monaco who was an avid oceanographer.  He asked them to study the sting of the Portuguese man-of-war.   They used the venom from both the man-of-war and the sea anemone in dog studies. 

Because the concept of vaccination was new to science, they wondered if they could “vaccinate” dogs with the venom to build up protection.  Unexpectedly (because they used too large of doses) and to their dismay, the second injection caused some of the dogs to die suddenly, because they failed to provide “phylaxis” (now called prophylaxis).  They called the events aphylaxis (eventually termed anaphylaxis) meaning “against” “protection”.  As a dog lover I’m sorry for the dogs, but I guess it would have been worse if they had experimented on the prince. 

Jellyfish belong to the phylum Cnidaria which refers to the cnida, a specialized explosive organelle that causes stings.  The cnida produce a variety of proteins which can lead to allergic sensitization: congestin, hyaluronidase, collagenase, proteinase, hypnotoxin, thalassin, nuclease, and phosphatase. 

There are 10,000 species of jellyfish and their numbers are increasing due to global warming.  The most common jellyfish allergy is skin allergy either immediate or delayed.  The immediate reaction is hives that occur in addition to the “stings”.  The hives respond to antihistamine therapy but the stings do not.  The delayed reaction is akin to poison ivy allergy in that an itchy blistering develops several days after the immediate stings.  This type of allergy responds best to steroids, either topical or oral. 

The next most common reaction is food allergy reaction with itchy rash and GI symptoms after ingesting jellyfish.  In some cultures, the umbrella (outer portion) of the jellyfish is a common food. 

Anaphylaxis is the rarest form of allergy but can be life threatening.  Most cases occur in people with frequent and repeated contact with jellyfish especially surfers and open water swimmers. 

Dear Dr. K; When I recently started taking Coreg for newly diagnosed hypertension my previously well controlled asthma got worse. Are they related?

Dear Dr. K; When I recently started taking Coreg for newly diagnosed hypertension my previously well controlled asthma got worse. Are they related?

The short answer is yes, the long answer requires explanation.  First of all, asthma and hypertension are both very common conditions with 9% of American adults having asthma and up to 25% having hypertension.  Certain factors can contribute to both conditions:  stress, obesity, sedentary life style, excess salt intake, and sleep-disturbed sleep.  Correcting these factors can help both conditions.

In terms of medications, many of the medicines used to treat asthma and hypertension can act on opposing sides of the autonomic nervous system.  The autonomic nervous system controls the smooth muscles found in both our bronchial tubes and our blood vessels and heart.  Unfortunately, medicines that can relax heart and blood vessel smooth muscle (thereby lowering BP) can sometimes constrict bronchial smooth muscle (narrowing airways and causing asthma). 

Coreg contains a beta-blocker meaning it blocks the beta input into blood vessels and the heart and thereby relaxes them and lowers BP.  Unfortunately, it also blocks beta input into bronchial tubes which causes them to tighten, thereby causing asthma.  Many of the medications used to treat asthma work through the beta system as stimulants (agonists).  Many inhalers contain short acting or long acting beta agonists: albuterol, Advair, Symbicort, Breo, Dulera.  Blocking the beta system reduces their benefit. 

Luckily scientists have come to understand this dichotomy. This has led to the development of “cardio-selective” beta blockers.  These drugs are much less likely to have negative effect on asthma as they are formatted to work mostly on the heart and blood vessels.  Perhaps your doctor could switch you from Coreg (a non-cardio selective) to a cardio-selective beta blocker. 

High Fat Diet and Food Allergy

High Fat Diet and Food Allergy

Over the past thirty years there has been a dramatic increase in both obesity and food allergy.  In fact, the rate of increase for both conditions has followed the same identical track.  For this reason, and others, scientists at Washington University School of Medicine have done exhaustive research to see if there might be a common cause.  As it turns out a high fat diet is the answer.  The rise in obesity is directly linked to the high fat content of “The Western Diet”.  As it turns out, a high fat diet also can lead to food allergy for three main reasons:  mast cells, gut permeability, and change in microbiota. 

Mast cells are the “worker bees” for allergic conditions.  They are the cells that contain and release histamine and other allergic mediators.  A high fat diet leads to an accumulation of excess Mast cells inside the intestine walls.  A high fat diet also makes the walls of the intestine more porous (or “leaky”) thus allowing greater penetration of food allergens.

Finally, a high fat diet alters the normal healthy microbiome towards one that is pro-inflammatory.  This increase in total body inflammation promotes both allergic and auto-immune conditions. 

PFAS

PFAS

PFAS stands for pollen food allergy syndrome.  It used to be called OAS (oral allergy syndrome) but the new name better characterizes the pathogenesis.  Using highly technical immunologic terms, it is called Class II food allergy.  Class I food allergy refers to the common/classic form of food allergy where sensitivity occurs due to ingesting the food.  In Class II food allergy, the sensitivity occurs from exposure to pollen and leads to cross reactivity with a food. 

The symptoms involve immediate itching and sometimes mild swelling of the lips, tongue, mouth and throat.  Sometimes the itching can even extend from the oral cavity to the back of the nose or ears.  Occasionally these oral symptoms are accompanied by difficulty swallowing and/or nausea.  Almost always the symptoms are both self-limiting and mild.  But the immediate nature of the onset makes people fearful of possible anaphylaxis.  That is why its important to distinguish PAS from traditional food allergy issues. 

The most common pollen-food cross reactivities are:  mugwort pollen and peach and chestnut; ragweed pollen and banana, melons, kiwi and peaches; grass pollen and tomato, peach, and apple; and birch pollen and apple, apricot, carrot, celery, cherry, chestnut, hazelnut, kiwi, peanut, pear, raspberry, soybean, strawberry, tomato and walnut. 

Of interest, cooking a food can sometimes degrade the cross-reactivity protein so that PAS doesn’t occur.  Otherwise, avoidance is the best therapy.

Q – Tips: COVID-19

Q – Tips: COVID-19

The two main tests being used during this pandemic are nasal swabs to detect active infection, and antibody tests to detect prior infection.    

The nasal swab uses a polymerase chain reaction (PCR) which is a chemical tool that amplifies tiny amounts of nucleic acid to allow detection of viral RNA.

Antibody tests fall into two main categories:  detection and protective value. The two main detection assays are for either spike glycoprotein (allows the virus to enter human cells) or nucleocapsid phosphoprotein (the most abundant protein).  Both can confirm a prior corona virus infection.  

Neutralizing antibody assay is used to determine if the presence of antibodies can “kill” (neutralize) the corona virus in a test tube.  This type of testing will be used to determine how effective corona virus vaccines will be.