15 Most Common Allergy Triggers and Reactions

What with so much office stress and other political worries, it seems that the world has forgotten to give us a good health scare so far… Simi - January 30, 2018

What with so much office stress and other political worries, it seems that the world has forgotten to give us a good health scare so far this year, but we don’t have to go too far back to think of the really frightening Ebola epidemic, the Zika virus, bird flu and swine flu to name just a few.

How irritating would it be laid low by things which are NOT illnesses? We all know someone these days with allergies of some sort or another. Allergies are the body reacting (or over-reacting) to often ordinary environmental factors as if it has encountered a dangerous virus or bacterium. Almost anyone can have or develop an allergic reaction to something or other, ranging from minor irritation to a life-threatening situation.

Sometimes it is difficult to distinguish between an irritation (such as hairy caterpillar stings), an intolerance (often relating to a type of food) or a genuine allergic reaction, although only the latter can be life-threatening for some people. There are often a variety of factors which impact on the severity of the immune reaction, from genetics to previous exposures among many.

Allergies are becoming more common among children for reasons not fully understood, so we should make sure we know how to deal with them. Knowledge, awareness, preparation and a little common sense can help you be prepared – as well as prepare to treat the symptoms of an allergic reaction if necessary. Sometimes allergies can be a nuisance, but sometimes they can also endanger your life!


Pollens are tiny, almost invisibly small organic particles released from almost all types of vegetation including grasses, flowers, and trees. Symptoms of a pollen allergy (i.e. hay fever) include sneezing, runny nose, nasal congestion and itchy, watery eyes. Some people are allergic to pollen in general while others react to specific plants. The sensitized sinus system makes the reactions even worse until you develop headaches from sneezing and coughing. Sensitive sinuses can begin to suffer from pollution as well.

The first step to winning control over your hay fever is to get to know your particular triggers: What time of year does it hit me? What exactly causes my hay fever? What are the warning signs in nature I should be watching out for? Do I need to get medically tested to find out what exactly I am allergic to?

The reason for this is that the anti-histamine medicine which are the most common drugs used, don’t just work immediately like headache tablets. The active ingredients need to build up in your body over time; so if you only start taking them when you start feeling symptoms, it’s going to be quite a while before you feel the benefits, and of course, one simply can’t take the medicine every single day of your life just to be sure. So get to know the early signals so that you can be prepared.

Weather forecasts (and weather apps) often include a pollen count forecast as well, so try and stay indoors on hot, windy days when pollen counts are high, closing windows and using air conditioning if you have it. If your car has air-conditioning, use that as well on high-count days.


According to the Asthma and Allergy Foundation of America, 15-30 percent of people with allergies have an allergy to dogs, cats, or other animals, with cats being the most common cause. Something in the immune system reacts badly to proteins secreted by oil glands in an animal’s skin and found on flecks of shed skin, as well as those in animal urine or saliva, can cause allergic reactions for some people.

Symptoms are similar to those described for hay fever above. The allergy can take two or more years to develop and symptoms may not subside until months after ending contact with the animal. Direct contact with animals is not always necessary to trigger allergies. For example, it could be caused by a pet that used to live in the house, or remnants carried on the persons living with animals.

As a result, it may be obvious that animals are the cause of your allergy. Symptoms may last for a very long time after exposure, so the causal relationship to pets may not be immediately obvious. If your pet is causing allergies, keep it out of your bedroom, avoid carpets in your home (which retain pet hair & skin), ventilate your house thoroughly and have the animal wash regularly. Thorough vacuuming may also help reduce the irritants in the house, especially if your cleaner specializes in removing pet hair and filters the air well.

If you suspect you have an animal allergy, but still want a pet, consider an animal with a shorter coat which tends not to shed as much. Research your pets before you decide. There are many benefits to having a pet, so think twice before abandoning the idea.


While drugs often have side effects, some people are allergic to certain medicines. Side effects are derived from the chemical nature of the drug, while allergies are derived from the person’s immune system. Allergic reactions may range from minor irritation to life-threatening situation. Symptoms of allergies to medications, such as penicillin or aspirin are very broad, from minor to life-threatening. They can include a skin reaction such as hives; or red and itching skin; itchy, streaming eyes; sinus congestion or swelling in the mouth and throat. The quicker you respond to your allergic reaction, the better and safer for you.

Since people’s first exposure to a drug is as a baby or small child, parents must take care the first time they give their child medicine. Check your family’s medical history in case there might be a genetic disposition towards such allergies. Adhere to recommended dosages and watch carefully for any negative reactions to the medicine. They can impact a child’s small body quickly and severely.

Remember also that livestock may be fed antibiotics and other medicines these days. You might react to these drugs in the food you eat. Animals may be dosed with drugs as a matter of course to prevent sickness which could spread quickly in the populous, confined conditions of many farm animals live in these days. Antibiotics may also be given to boost the growth of the animals.

Medic-alert bracelets are useful tools to make sure that you are not administered the wrong drugs when you are unable to warn carers of your allergy. If you have allergies of any kind, you may be more likely to have an allergy to drugs than others.

Insect Sting

Most insect stings, usually from bees or wasps, will cause a painful reaction around the site with pain, redness, and swelling. This is caused by the venom of the sting rather than an allergic reaction. There is a very low proportion of people (less than 2%) who will suffer a severe allergic reaction to an insect sting. Reactions may be severe or even life-threatening due to their immune system overreacting to the poison.

Possible symptoms of an allergic reaction include extensive swelling and redness from the sting or bite that may last a week or more, nausea, fatigue and low-grade fever. Symptoms of a serious reaction include difficulty breathing, hives or rashes, swelling of the face, throat or mouth, rapid pulse, dizziness, or a sharp drop in blood pressure. Those severely allergic should always carry an EpiPen with them.

Research in Switzerland among bee-keepers shows that these people suffer an (ordinary) immune reaction to bee stings during spring, and thereafter the body ramps up the defenses so that they have some immunity for the rest of the year. The immunity is lost each year. Researchers hope to use this information to help people with severe allergies to bees. I should mention that these beekeepers were being stung on average 13 times a week, so I am not sure if the cure is worth it for us ordinary folk.

The simplest way to prevent insect bites is to be aware of the insects and stay away from them. Be aware that bees are attracted to sweet food and drinks. While we are more aware of flying bees, they are often found on the ground among fallen blossoms, so never go barefoot. Bright-colored clothing and fragrances will also attract bees.


Natural latex derived from rubber is found in certain medical equipment such as medical gloves, condoms, and other medical items. Prolonged exposure to these items can trigger an allergic reaction which may range from skin irritation to asthma-like breathing difficulties to anaphylactic shock. Allergic reactions to latex are usually caused by prolonged exposure to the substance, so medical staff who regularly wear latex gloves, or patients who have had lots of surgical procedures or lots of dental work are susceptible.

Sufferers are often people with a proclivity for allergies, and may also suffer from hay fever or food allergies. People who have multiple allergies may increase the likelihood of a bad reaction to latex if they have been eating foods they are allergic to, or are fighting hay fever at the same time. Allergic reactions include skin rash, eye irritation, runny nose, sneezing, wheezing and itching of the skin or nose. Anaphylactic shock can occur in rare incidents, a life-threatening reaction that can cause difficulty breathing and a drop in blood pressure.

Latex gloves are often dusted with latex dust to make it easier to put them on, so sufferers only need to be in the vicinity of latex to react. Those allergic to latex should wear a Medic Alert bracelet and carry an adrenaline (epinephrine) auto-injector. They should always warn any medical personnel you encounter to treat them in a latex-free facility only.

Many medical facilities have moved to synthetic or low-protein latex supplies and this has had a very positive effect on the incidence of this allergy. While the majority of suffers are medical staff, an allergic reaction in a patient who is already poorly only helps make their weakened condition even worse.


When one thinks of mold, one thinks of dark, moist places in the home where these dark spots appear and thrive. However, molds are fungi and thrive in outdoor places such as damp, rotting logs or leaf litters or in the dirt. Molds and their spores produce allergens, irritants and, in some cases, potentially toxic substances. Inhaling or touching mold may cause allergic reactions in sensitive individuals.

Mold spores in the sinus system will trigger the same symptoms as hay fever, while spores drawn into the lungs will result in symptoms similar to asthma. Mold acts as an irritant as well as an allergen, although the body’s reaction to both is similar. It may be difficult to diagnose mold as the cause of an allergic reaction because mold spores are so ubiquitous.

Allergic reactions can occur throughout the year, but people reacting to outside sources usually suffer more in the summer or autumn. Indoor reactions will be more likely in colder weather when the house is closed off from fresh air. If you know that the irritants are outside, reduce your time outdoors when mold counts are high, or wear a dust mask. People in areas with cold winters, where the house is closed off from outside air, can easily succumb to mold allergies when they breathe in uncirculated air for extended periods.

Reduce mold inside the home by keeping air conditioner filters clean and reduce the humidity as much as possible. General cleanliness will also help, but be especially wary of out-of-the-way spots such as under the sink. Remember that the chemical sprays which combat mold infestations in the house are usually harsh in their own right and care should be used to reduce exposure to them.


Nobody likes cockroaches, but they cause more damage in your home than just being unwanted guests. Their droppings, saliva or shed body parts contain an allergenic protein (so stomping on them is only part of the solution). Typical cockroach allergy symptoms include coughing, nasal congestion, skin rashes, wheezing, ear infection and sinus infection.

Often, these symptoms become chronic, while often other allergens like hay fever cause only seasonal discomfort. American researchers calculate that nearly all homes in urban areas have cockroaches and that the majority of people with asthma living in those home owe their symptoms to a cockroach allergy. These insects, known for their resilience anyway, do even better in warmer climes.

It can be difficult to impossible to get rid of cockroaches completely from your home, particularly if you live in a block of flats where insects can easily pass back and forth between neighbors, but it’s worth the effort. Kill cockroaches by using cockroach traps or pesticides (but remember that a pesticide that can take out a cockroach isn’t going to do you any good, either), keep a clean kitchen and repair cracks and holes in floors, walls, and windows to prevent their entry into the home.

Remember that cockroaches can get through the very tiniest of spaces. Repair any leaks or drips that can supply them with water and keep all food tightly sealed and clean up any messes immediately. Vacuum up all that cockroach detritus. Avoid piles of papers or anything bugs can use as home or hiding places. You can see that keeping a clean house which discourages cockroaches will have other advantages as well, such as repelling rodents, other insects, mold, and germs.


House dust mites are arthropods (with eight legs like spiders) which are too small for us to see. They feed on the dead skin cells of humans and their pets, as well as on pollen, bacteria and fungi. The 1.5 grams of dead skin and hair that you shed daily will feed a million dust mites! They like areas such as beds and carpets where dander collects.

We will never completely eradicate these tiny bugs from our homes, but we can at least reduce their populations. The recommendations to repel cockroaches will help keep our dust mite population down as well. Mites enjoy a humid environment, as they can absorb water from the air, so reducing humidity as we did for mold is going to help us eradicate dust mites as well.

Dust mites may be the most common cause of allergies and asthma in the world. Symptoms of mite allergies are similar to those of cockroach allergies. Symptoms of asthmas include difficulty breathing, a tight or painful chest, a whistling or wheezing sound when breathing out and disturbed sleeping due to shortness of breath, coughing or wheezing. There are some things you can do to keep the mites in check.

Cover mattresses and pillows in allergen-impermeable covers with pores too small to allow them or their excrement to enter. Wash clothes and especially bedding in a wash hot enough to kill them. Don’t install carpets and buy rugs and carpets that are washable (preferably in a hot wash). Don’t rely on your vacuum cleaner to help you eradicate the problem; most of the dust mites live too deep into your carpets and fabrics to be reached by your vacuum.


Food allergies are an abnormal immune response to specific foods. Food intolerance differs from allergic reactions, where people either struggle to easily digest certain foods – milk and wheat are common causes of intolerance, or show skin problems such as eczema. The symptoms of an allergy are quickly apparent while those of intolerance take time to manifest. Although the symptoms may not be as severe as allergies can be, intolerances can be as disruptive as any allergy.

Milk, shellfish, nuts, and wheat are among the most common foods that cause allergies. Symptoms, which can include asthma, hives or rashes, vomiting, diarrhea and swelling round the mouth, can be severe and may include difficulty breathing or collapse. It is believed that around 4 to 8% of people have at least one food allergy, varying across a wide spectrum of severity.

They are more common in children (especially boys) than adults, with the prevalence increasing in developing countries. There is a genetic aspect to food allergies, and children of parents with food allergies have a much higher chance of having one. Try your child on small amounts of foods that are well-known allergens, then wait and see how they respond. Be particularly careful with foods known to cause severe reactions in some people, like nuts and shellfish.

Educate your child as much as possible if they have a food allergy. Allergenics appear as ingredients in some surprising foods! Always keep the appropriate treatments to hand, including an EpiPen. Children may outgrow minor food intolerances or allergies, such as milk or wheat, so re-test these foods carefully as they grow. Children with severe reactions to things like nuts or shellfish will always have that allergy.

Read More: 10 Anti-Allergy Superfoods.


While perfume comes to mind under this rubric, many ordinary household items that contain fragrances of one kind or another. Think of soaps and shampoos; cleaning products and air fresheners; as well as laundry detergents, cosmetics, and scented candles. Allergic reactions to these products vary across the people who encounter them, and the variety of chemicals involved, which makes it hard to offer a standardized description of this allergy.

There are about 100 chemicals in common use as fragrances, but 5,000 chemicals that fall under this banner. Symptoms vary from mild to severe, but usually ease immediately away from the scent. For some, symptoms get worse the more often the fragrance is encountered. Many scientists argue that fragrances are an irritant rather than an allergen. Irritants do not impact the immune system but irritate sensitive membranes such as the skin or the sinus system.

The most common symptom is sneezing, but symptoms such as contact dermatitis, asthma, and headaches, among many others, often require medical help or advice. Around 2-4% of people react badly to require medical attention, but up to 30% of the population declare themselves sensitive to some fragrance or other, with 20% of people reacting to air fresheners, and 10% to laundry detergents.

Products marked “fragrance-free” may still contain some fragrance chemical or another, although they don’t usually cause the same problems. People who suffer from asthma or whose sinuses are inflamed through illness are often more sensitive to fragrances. The best way to deal with this problem is simply to try and stay away from these chemicals. This means identifying and eschewing products which produce symptoms for you, and buying fragrance-free products over others where possible.

Cell Phones

Cell phone use causes a number of medical problems, from car crashes to bumps and bruises from not paying attention to where you walk. Here we are only interested in the allergic reaction some people experience from talking too much on the phone. Nickel, cobalt, and chromium in the phone case can all cause contact dermatitis if the phone is held to your ear for extended periods, with nickel identified as the most common villain.

Nickel-related Allergic Contact Dermatitis (ACD) usually affects wearers of jewelry. A lot of gold-plated jewelry, such as pierced earrings has nickel content and up to 17% of American women and 3% of men have suffered symptoms. Certain phones with a metal casing are the main cause of ACD, with around 10% of people showing sensitivity to nickel. Extended talking or typing can cause, red, itchy ears, cheekbones or hands.

Other symptoms of prolonged use include dry, itchy skin like eczema, redness, blistering, lesions, and even oozing on the face or ears, but most of these are rare. Carrying the phone close to your skin can also cause ACD, such as girls tucking their phone into their bras, or thighs when they are kept in pockets. It will surprise nobody to know that more than half of those diagnosed were teenagers.

The first case of ACD was diagnosed in 2000, with a 40% increase in cases in the short period from 2010 to 2012. Preventative measures are obvious: Consider purchasing a phone with a non-metallic frame, use a headset for phone calls or buy a protective plastic cover that covers the face of the phone as well as the back. Many phone manufacturers have stopped using metal casings.

Black Henna Tattoos

You have probably seen the gorgeous designs that are drawn on the hands of Hindu brides, among others. Many people would love to take the opportunity to have their hands similarly decorated at fairs and festivals. To be clear, real henna is not black but burnt orange or brown in color. Henna temporarily stains the skin a dark red color. The paste is used by those offering black henna temporary tattoos.

The main culprit in the black “henna” is a chemical called para-phenylenediamine (PPD), which is usually an ingredient in hair dye. In commercial products like hair color, it is strictly controlled. Home dye kits carry explicit instructions and warnings about how the dye is managed, with plastic gloves to protect the hands and clear instructions and warnings about how long the dye should stay in the hair.

Some people can still react badly to hair dye even after following the instructions to the letter. Hobby henna artists, however, are not controlled. Some people react to the PDD with a burning sensation. Some people may feel a little discomfort, such as burning or tingling, while others experience real chemical burns, with severe pain, swelling, redness, and blisters. Some people now have the shape of the original pattern of the henna design etched into their skin by burned tissue!

Even in less severe cases, a bad reaction to a henna tattoo can leave you sensitized or oven allergic to PPD and you may experience an adverse reaction in the future when you use hair dye, even though you have used it before. So always carry out the allergy test prescribed in the instructions even though you have used the hair dye before.


While many people joke about being “allergic to exercise” it is a real, though rare, phenomenon. It is called Exercise-induced anaphylaxis (EIA). It is often triggered by vigorous exercise, but cases exist where merely walking or gardening was sufficient to induce an attack. Often, certain additional factors other than exercise contribute to the attack, such as certain foods, alcohol, temperature, drugs (e.g., aspirin and other nonsteroidal anti-inflammatory drugs), humidity, seasonal changes, and hormonal changes can all contribute to the attack.

Often different combinations of factors can precipitate an attack. While food is often a factor, the attacks only occur where both factors contribute. Foods that are often implicated in allergies are frequently implicated as co-factors here, although many other foods can help instigate an attack. In one case, a combination of two specific foods was required to instigate an attack. In other cases, any food at all would suffice.

Sometimes the co-factor has been an inhalant such as those related more to hay fever or other allergies. Just to add to the confusion, there is some evidence that genetics may also play a part and that susceptibility for EIA may be inherited. As yet, we do not fully understand the interplay of the many factors which can contribute to EIA. Attacks are often not caused by the same co-factors.

Treatment is limited to reducing and monitoring exercise levels and trying to tie down trigger factors in individuals. Scientists believe that the confusion of factors involved may mean that the prevalence of the disorder has been underreported in the past and that more people are affected by the condition. Indeed, they believe that the incidence of the ailment is increasing.

Cold Hives

Cold urticaria or Cold Hives, is a condition where hives or weals are induced on the skin by cold or wet weather, after swimming in cold water or even with some ice cubes. Sweat cooling on the skin on a hot day may be enough to initiate an attack. In fact, any quick reduction in temperature may be enough to start an attack after only a few minutes of exposure.

These hives may remain for a minute or two or up to a few days. Other symptoms can include swollen or red hands. Although these are common reactions to cold, the hands will swell under minor inducements, such as holding a cold glass. Equally, red hands which stay red for longer are another diagnostic measure. Severe cases begin to show symptoms of dizziness or even anaphylactic shock, although rarely to a life-threatening degree.

It is estimated that only one person in a million suffers from this disorder to a degree where they are diagnosed with the disorder, but between 15 and 25% of people may experience the disorder during their lives, though usually so mild that they may not even notice. The weals usually itch, as may the hands and feet, which may also swell. There seems to be a genetic factor to the condition, although other cases show no familial precedent.

As yet, there is no scientific explanation as to why people suffer from this disorder. Antihistamine treatments are effectively prescribed for this condition. Under medical supervision, patients should try and establish the conditions which will induce an attack by looking at factors like temperature thresholds and the length of exposure required to induce an attack in order to help people manage their condition adequately.

Hairy Caterpillars

Some caterpillars, such as the gypsy moth, have hairs or fibers on their body which can break off, embed themselves in human skin, and irritate or transmit a toxin into the skin. Magnified, the barbed hairs resemble tiny versions of a porcupine’s quills, except that they contain a poison sac. Usually, it is necessary to touch the caterpillar to be stung, as the hairs are completely defensive and cannot be actively administered; but sometimes loose hairs can also cause irritation.

Most cases are caused by accidentally brushing against a caterpillar, although children may find these baroque caterpillars too fascinating to ignore. Sometimes loose hairs can be inhaled, causing breathing problems; or even injuring an eye. Touching some species of these caterpillars may cause only a mild tingling sensation, while touching other species may cause instant pain, followed by irritation for a period after and a raised, red weal or rash.

The severity of the injury depends partly on the sensitivity of the patient, the severity of the contact and the species of caterpillar. In most cases, symptoms are reddening and swelling of the skin and small bumps which are gone within the hour. More severe symptoms may include itchiness, blistering, or eczema-like symptoms which may last for weeks.

Antihistamine or hydro cortisol creams are usually effective. In their absence, an ice pack or a paste of baking soda will usually provide relief. Placing a piece of tape, preferably duct tape, on the affected skin and then pulling it off sharply is a good way of removing the hairs embedded in the skin. Wash the area well and wash all clothes thoroughly to remove any loose hairs which may remain.