Dr. Barry Dworkin » Allergy

Southern Exposure: Day of the Tentacle

Dr. Barry Dworkin — Sat, 12 Mar 2005 03:21:30 +0000

Originally published in The Ottawa Citizen March 11, 2005

The thrill of the winter sojourn to warmer climes and ocean activities like scuba diving, surfing and snorkeling, among others, can lead many to overlook other notable health and safety precautions.

If you’re heading south for some fun in the surf, remember the ocean is an alien world with creatures that, for all their beauty, can be a literal shock to the system.

What do you do when stung by a jellyfish, step on a sea urchin’s spine, encounter the whip of a stingray’s tail, or eat a poisonous fish?

Certain reef fish like grouper, king mackerel, sturgeon and snapper can ingest microscopic organisms called dinoflagellates either directly or by eating smaller fish. One particular species, gambierdiscus toxicus, produces a toxin that becomes increasingly concentrated as it travels up the food chain.

Thousands of people eating these fish found around Hawaii, Florida, Puerto Rico and the U.S. Virgin Islands can develop Ciguatera (seeg-wha-terra) poisoning. The severity of poisoning depends on the fish size and the number of exposures. The classic symptom found in 80 per cent of patients is a cold sensation reversal, where hot sensations are perceived as cold and vice versa.

Gastrointestinal and neurological symptoms usually begin one to six hours after ingestion and last seven to 14 days, and in some cases months to years. They include nausea, vomiting, watery diarrhea, abdominal pain, numbness, vertigo, severe weakness, muscle aches, slowed heart rate (bradycardia), low blood pressure (hypotension), diffuse pain and decreased vibration and pain sensations.

There is no immediate cure, only symptom relief. Cooking, freezing, salting or smoking the fish does not deactivate the toxin. If these fish are eaten, avoiding eating the fish’s internal organs like the liver because the toxin concentrates in these areas.

Travellers to Hawaii and California who eat tuna or mackerel may develop scombroid. Poor handling and refrigeration of the fish can cause a buildup of histamine and histamine-like substances within the dark meat. The person develops symptoms 30 minutes after ingestion. Symptoms can last about eight hours and include flushing, nausea, vomiting, diarrhea, severe headache, palpitations, abdominal cramping, dizziness, dry mouth, hives, and red eyes.

Treatment includes the use of antihistamines administered by mouth, intravenous or into the muscle, depending on symptom severity.

Encounters with jellyfish are memorable. Their long tentacles have stinging cells, or nematocysts, that sting. Nematocysts found on amputated tentacles and dead jellyfish will sting as well.

Symptom severity depends on the number of stinging nematocysts, the toxicity of the venom and each person’s unique reaction. The poison is destructive; it damages skin, red blood cells, heart tissue and nerves.

The most common symptom is local pain followed (in order or likelihood) by a “pins and needles” feeling (paresthesias), nausea, headache, chills and, rarely, cardiovascular collapse or shock. Symptoms can last up to three days.

Treatment focuses on pain relief and controlling neurologic symptoms. Use gloves or forceps to remove any visible tentacles. Avoid touching towels used to wipe off the nematocysts; they will sting. A 30-minute application of vinegar (five per cent acetic acid) will stop any remaining nematocysts on the skin from releasing their venom. Salt water is a good substitute if vinegar is unavailable. Never use fresh water because it will stimulate venom release.

Scraping the nematocysts off the skin using shaving cream and a razor is another solution. There are reports that cold and hot packs can help sooth the pain.

Stepping on a sea urchins’ toxin-coated spines will cause pain and burning and occasional skin discolouration lasting about 48 hours. The spines will break if you try to remove them by hand. Fragments will remain embedded in the skin and can cause infection. Surgical removal and wound debridement may be necessary.

The stingray’s venomous spine is at the end of its tail. The venom will reduce blood flow to the affected limb causing tissue death and destruction, poor wound healing and infection.

Intense pain is immediate and can be accompanied by salivation, nausea, vomiting, diarrhea, muscle cramps, shortness of breath, seizures, headaches, muscle cramp and cardiac arrhythmias. Fatalities are rare.

Bleeding from the puncture site is controlled by direct pressure to the wound. Hot water soaks will help reduce the pain.

Wound care includes thorough rinsing of the affected area with fresh water. Patients should check for redness and swelling at the site; a sign of infection. Sometimes, part of the spine will remain embedded in the tissue; surgical removal may be necessary.

A tetanus shot may be required for stingray and sea urchin stings. Although fatalities are rare for all these toxic reactions, prompt recognition of the symptoms can lessen the discomfort and morbidity.

Leaves of three, let it be

Dr. Barry Dworkin — Wed, 25 Jun 2003 00:46:16 +0000

Originally published in The Ottawa Citizen June 24, 2003
Original Title: Poison Ivy

During the summer months, it is common to see people come in with peculiar linear or blotchy blistered red rashes. Welcome to poison ivy country.

Poison ivy was named in 1609 by adventurer, explorer and president of the British colony of Jamestown, Capt. John Smith. It belongs to the cashew family.

Found in areas of southern Canada and parts of the United States, it grows as a vine on trees or as a bush in grassy or bare areas. Often you will encounter it along the edges of roads, footpaths or fields, a new shopping mall or a housing subdivision where it does not have to compete with other vegetation. Hiking trails in and around Ottawa-Gatineau post poison ivy warnings.

Poison ivy is readily identifiable. The leaves grow on the stalk in groups of three. Their colouration starts as red in the spring, changing to shiny green in summer, then yellow, red or orange by the fall. Poisonous white, waxy clustered berries appear later in the season.

Poison ivy is related to poison oak (Pacific Northwest and western Canada) and poison sumac (eastern United States). However, these plants are shrubs and have seven to 13 leaves per stem, unlike poison ivy.

The sap (oleoresin) from the vine or shrub, and urushiol oil (from the Japanese, urushi meaning lacquer) are intensely irritating to the skin. One billionth of a gram (a nanogram) will cause a rash. An affected person’s average exposure is 100 nanograms. To put this natural irritant’s strength in perspective, seven grams (a quarter-ounce) would be enough to cause a rash for everyone on Earth.

The oleoresin can remain active on any surface, including dead plants, for up to five years. Collecting firewood over the winter can inadvertently include the poison ivy vine. Burning the vine will release the urushiol into the air leading to lung and eye irritation.

Poison ivy rash is not an infection but a chemical irritation. The fluid within the rash’s blisters does not contain the oleoresin and will not spread the rash. It will spread from person to person if the hands or clothing remains contaminated with oleoresin. Washing the oleoresin from the skin, clothing and surfaces eliminates the risk of contaminating others.

About 50 to 70 per cent of the population is allergic to urushiol, especially those with cashew allergies. The rash appears 24 to 48 hours after contact with the resin. It quickly becomes red and intensely itchy. Blisters can form. Often, the rash appears in streaks where the vine has scratched the skin.

The rash usually resolves one to two weeks after exposure. Some people with no previous exposure to poison ivy will develop the rash seven to 10 days after exposure. Frequent exposure to poison ivy increasingly stimulates the allergic response and the rate of rash and blister formation.

There is a 10-minute window of opportunity after exposure when thorough soap and water washing of the skin can minimize the chance of a rash. Remove any clothing contaminated by the oil, and wash it thoroughly, being careful not to touch the clothes with your bare hands.

Treatment options depend on the severity and discomfort of the rash. The use of antihistamines, cool compresses, Aveeno colloidal oatmeal baths and topical steroid creams can limit mild to moderate reactions.

Do not intentionally break the blisters. They act as a protective covering for the healing skin underneath them. It can lead to secondary bacterial infections, complicating treatment and potentially worsen scarring. Consult your doctor if large blisters form on your hands. It may be necessary to drain the blisters to allow more freedom of movement, reduce hand stiffness and loss of function.

Wet-to-dry dressings on oozing blisters can dry them out so you can apply steroid creams. Your pharmacist can help prepare a Burow’s solution. Apply this solution to a single thin cotton sheet or fabric and apply it to the skin. Allow the fabric to dry over 30 minutes. Repeat the procedure several times. For those who suffer extensive skin damage, your doctor may prescribe a short-term course of oral steroids. The rash usually resolves within two to four weeks. Prevention is a matter of avoiding the plant. Pets — especially dogs — can pick up the resin on their fur, so be mindful after Greenbelt excursions.

Resources:

http://poisonivy.aesir.com/;
http://ncnatural.com/wildflwr/obnxious.html;
http://www.aad.org/pamphlets/PoisonIvy.html

© Dr. Barry Dworkin 2003

One allergy can lead to many sensitivities

Dr. Barry Dworkin — Wed, 21 May 2003 00:48:08 +0000

Originally published in The Ottawa Citizen May 20, 2003
Original Title: How to Produce a Natural Allergy

Proteins in some plants and products so closely resemble pollen antigens, they can confuse the immune system, trigger allergic reactions.

It’s spring and that means allergies are again exacting their seasonal vengeance.

Many people don’t know it, but pollen allergies can increase the risk of severe allergic reactions to other plants, foods and herbal or naturopathic remedies.

The proteins (antigens) within these plants and products resemble pollen antigens: the proteins that trigger an allergic reaction. The similarity can confuse the immune system, causing an allergic response.

This cross-reactivity of antigens in an unsuspecting person is an important concept in allergy and immunology. For example, a person allergic to birch pollen may have an allergy to apples.

Fifty to 90 per cent of people allergic to birch pollen can react to nuts, fruits such as kiwi, apples, pears and plums and vegetables like potatoes, tomatoes, celery and carrots.
Grass pollen has a cross-reaction relationship with carrots, potatoes, celery, tomatoes, buckwheat, melons, oranges and Swiss chard.
Ragweed sufferers should be careful about zucchini, cucumbers, bananas, melons (cantaloupe, honeydew and watermelon), apples, chamomile tea, honey, nuts and sunflower seeds.
Some foods will cause oral allergy syndrome in people afflicted with airborne allergies. The symptoms include a raw, itchy rash around the mouth. Some people develop a full-blown allergic reaction.

In the spring 2003 edition of the Allergy and Asthma News, Ottawa allergist Dr. Antony J. Ham Pong writes about allergies to herbal products: Hay fever (ragweed allergy) sufferers are at risk of severe allergic reactions or anaphylaxis if they use certain herbal and naturopathic remedies.

Chamomile, feverfew and echinacea belong to the compositae plant family, which includes ragweed, goldenrod, chrysanthemum, sunflower, sagebrush, mugwort, marigolds and daisies.
Chamomile, used as a digestive aid, to treat menstrual cramps, as an enema preparation and as a topical antibiotic, increases the risk of anaphylaxis and death.
Echinacea, considered by some to be an immune booster and to treat allergies and colds, can itself cause anaphylaxis, allergic skin rashes and asthma attacks. Feverfew, used to treat migraine headaches, produces similar reactions.
Bee honey, a food tonic, can contain pollen grains and antigens leading to hives, an itchy mouth and throat and anaphylaxis.
Royal jelly — the secretion from worker honeybees — may contain compositae pollens and may cross-react with dust mites.

Several products interact with standard allergy medications: the antihistamines and decongestants. They can augment the sedating effects of antihistamines found in cough and cold remedies like dephenhydramine (Benadryl), hydroxyzine (Atarax) and chlorpheniramine (Chlor-Tripolon).
Kava’s sedating effects are used to treat anxiety, stress and insomnia. Unfortunately, it can lead to excessive sedation and poor co-ordination when combined with certain antihistamines. Health Canada does not recommend its use because it can cause severe liver toxicity.
Valerian can cause similar side effects as Kava.

Ephedra is used to treat asthma, colds, hay fever, obesity and for bodybuilding. Using decongestants like pseudoephedrine (Sudafed) in combination with ephedra can cause dizziness, headaches, irregular heart rhythms, increased blood pressure, seizures, tremors, strokes and death. Health Canada also issued a warning about ephedra.
Cross-reactivity may explain why workers such a nurses who use latex gloves often develop an allergy to the gloves. The raw material for latex comes from trees. Latex can cross-react with avocado, kiwi, banana, peaches, chestnuts and melons. Changes in latex production may leave more antigens within the final product, increasing the chance of an allergic response.

According to allergy specialist Dr. Yezdi Patel, people who eat shrimp, celery, carrot or dillweed prior to aerobic exercise may experience an allergic reaction. The mechanism that causes the reaction remains unknown.

Future research may help find better ways to reduce the risk and relieve allergy symptoms. Consult your doctor or pharmacist about potential herbal/drug interactions and allergy risks.

© Dr. Barry Dworkin 2003

Know how to use an EpiPen

Dr. Barry Dworkin — Wed, 16 Apr 2003 00:43:45 +0000

Originally published in The Ottawa Citizen April 15, 2003
Original Title: When to use an EpiPen

A recent pharmacist’s study presented to the Canadian Society of Allergy and Clinical Immunology indicates 63 per cent do not know how to use an EpiPen and 62.5 per cent cannot recognize the signs and symptoms of a severe allergic reaction (anaphylaxis).

Medications (penicillin, nonsteroidal anti-inflammatory drugs and aspirin, chemotherapy agents and angiotensin-converting enzyme inhibitors (ACEs)), bee and wasp stings, milk, seafood, nuts, blood transfusions, exercise and other chemical agents can trigger anaphylaxis.

The most common food allergies children develop in their first three years of life are to cow’s milk, peanuts, soy, eggs, shellfish and wheat. Peanuts, nuts and fish tend to be lifelong.

Two cell types, mast cells and basophils, are responsible for the allergic response. It is unknown why the response varies between people. Some develop a few hives or itchy skin whereas others develop a life threatening condition when the mast cells and basophils release abnormal quantities of chemical substances including histamine.

The blood vessels will dilate and leak fluid into the surrounding tissue causing swelling (angioedema) of the skin. Severe fluid loss leads to a collapse of the circulatory system.

The smooth muscle rings that encircle the airways (bronchi) will constrict. The airways themselves will produce copious amounts of mucous. The combination of these two effects plugs the airway making it impossible to breathe. Fluid can accumulate within the lungs leading to heart failure.

These and other reactions usually develop within five to 60 minutes after exposure. There can be a delay of one to eight hours before anaphylaxis occurs so vigilance is a priority.

The symptoms include:

Itching, flushing, hives and swelling of the skin and sweating
Itching, tearing and swelling of the tissues around the eyes
Nasal congestion, runny nose, sneezing and a metallic taste in the mouth
Difficulty breathing, wheezing, increased airway secretions and mucous production, swelling of the upper throat, blueness of the skin (cyanosis), hoarse voice, sounds of laboured breathing and a choking sensation
Very rapid or very slow heart beat, an irregular heart beat, low blood pressure and cardiac arrest
Nausea, vomiting, abdominal cramps, bloating and diarrhea
Dizziness, weakness, fainting, a fear of impending doom and seizures
Ninety per cent of people with allergic reactions have hives and skin swelling after feeling itchy, flushed and fearing impending doom.

Breathing difficulties occur in 50 per cent of these people especially those with asthma. Gastrointestinal symptoms and extremely low blood pressure (anaphylactic shock) occurs in 30 per cent.

Five to 20 per cent of people may have an initial allergic reaction that resolves but recurs one to eight hours later. Be on guard for this phenomenon. This happens when a person develops symptoms 30 minutes after exposure and in those orally ingesting the substance.

People at greatest risk of anaphylaxis have a history of asthma, eczema, allergic rhinitis (nasal allergies) and hives. Injection and intravenous administration of the allergen is likely to be more severe than if swallowed. Inhalation can provoke a response.

In the event of anaphylaxis, epinephrine will give you 15 to 20 minutes to get to an emergency room. Epinephrine counters the allergic response by constricting the blood vessels, relaxing the smooth muscle of the airways to improve breathing, stimulating the heartbeat, and reversing hives and swelling about the face and lips. Antihistamines will not reverse anaphylaxis fast enough to make a difference.

Emergency epinephrine provided in the EpiPen format is a spring-loaded syringe containing a pre-measured dose of epinephrine. A junior format is available for children weighing under 15 kilograms or 33 pounds.

To use the EpiPen follow these directions.

Slide the protective plastic sleeve off the unit
Remove the gray safety cap. Do not touch the black plastic tip.
With your dominant hand hold the EpiPen and position the black tip against the fleshy outer portion of the thigh. Keep all fingers clear of the black tip.
Push the pen against the thigh for five to ten seconds. Massage the area after the injection. Pain is minimal
A needle sticking out the end of the pen after you are done indicates proper delivery of the medication into the skin
Call 911 or seek emergency medical assistance.

You can inject through thin clothing if need be. View an animated version of EpiPen technique at www.epipen.com. The Calgary Allergy Network is another source of information (http://www.calgaryallergy.ca/Articles/epipen.html).

Your pharmacist can demonstrate how to use the EpiPen. An Ottawa company, Allergy Essentials (www.allergy-essentials.com) sells EpiPen trainers (fully functional without the needle for $6.50). Please take the few minutes to learn to save the time of your life.

Allergies start in your home

Dr. Barry Dworkin — Wed, 02 Apr 2003 00:28:00 +0000

Originally published in The Ottawa Citizen April 1, 2003
Original Title: Mighty Mites!

Allergies affect millions of people in North America. Although medications help to control asthma, allergic rhinitis and eczema, control of our local living environment is essential. Prevention can reduce or eliminate the need for medications.

Our homes are hosts to millions of creatures and organisms that produce waste material. This material (allergens) is the source of allergy-based misery. Without proper identification of these allergens, it is difficult to provide long-lasting relief.

Over years of exposure to allergens, the immune system tends to overreact and produce an allergic response. This process is called sensitization. Exposure to various household allergens can lead to dry skin rashes or eczema, asthma, stuffy nose (rhinitis) and watery eyes (conjunctivitis). Allergy testing helps determine those allergens responsible for these conditions.

Dust mites infest our homes. These critters, related to the spider family, are 0.3 millimeters in size and love to eat our dead flaking skin. They live in dusty places with an ambient temperature of 21°C and relative humidity of 70 per cent. The mite’s fecal pellets cause the allergy. These relatively large pellets (from a microscopic standpoint) only remain airborne for several minutes once disturbed.

The areas of your home prone to these guys are carpets, pillows, mattresses, drapes, stuffed animals, clothing and upholstered furniture. Since these items are frequently used, the pellets will fly.

A pet’s skin, saliva, urine and feces provide a rich allergen source. Cat dander is the worst offender. It can remain airborne for some time, enough to spread throughout the house. Dander levels can remain in the house an average of 20 weeks after the cat has moved on. Further, it is impossible to remove cat dander from bedding, mattresses, carpets and furniture.

Cockroach allergens, found in household dust, have a strong link to asthma according to some studies. Roaches tend to congregate in dark areas of the kitchen feeding off crumbs and scraps of food falling into the nooks and crannies.

Indoor and outdoor fungi or moulds, Cladosporium, Penicillium, Aspergillus, Aternaria and Ganoderma produce spores that can cause asthma. The Weather Network (http://www.theweathernetwork.com/features/pollen/) reports the summertime spore counts.

Environmental control measures are essential to prevent or minimize allergic reactions. Indeed, identification and subsequent eradication of the offending allergens early in a child’s life can reduce the risk of asthma. Medications and allergy shots should be part of the treatment if necessary and not the sole therapy.

If you smoke in the house, stop. Smoke permeates throughout the house even if you lock yourself in a room. Children are most susceptible to the affects of second hand smoke increasing their risk of lung disease, asthma and ear infections. Smoking during pregnancy increases a child’s risk of asthma twofold and can cause a three to five per cent reduction in lung function.

Dust mite control will lead to a cleaner less irritating environment:

Pillows and mattresses should have a vinyl or semipermaeable cover. This can reduce the population 100 to 1000 fold
Wash all sheets, pillowcases and comforters every one to two weeks in hot water (54°C or 130°F).
Dry cleaning and tumble drying at 54°C will kill the mites
Remove bedroom carpeting and any that overlies concrete. Regular vacuuming does not remove the dust mites.
Wet mopping all vinyl and hardwood floors weekly can remove 90 per cent of the allergen.
Reduce indoor humidity to 50 per cent or less.
Ensure that your child’ stuffed toys are washable. Throw out those that are not.
Chemical agents that kill mites are not effective.
Since pet allergy sufferers rarely remove their pet from the home, the next best choice is to keep them out of the bedroom and off the carpets and upholstered furniture.

Avoidance of pets during infancy is not a recommendation. There is some evidence to suggest exposure at this age can reduce the risk of asthma and allergies.

Any way you can kill cockroaches is acceptable. Share your method with others. Clean up any food spills and keep the kitchen spotless.

Indoor moulds need moisture to grow. Check for any water leaks or damp areas. Use a dehumidifier in the basement to reduce the humidity level to less than 50 per cent.

These measures are relatively easy and economical to institute. Most people suffering from asthma should benefit from allergy testing. These straightforward steps can reduce exposure to substances that allow you to smell the roses – provided you are not allergic.