Allergies

chapter 21 Allergies

INTRODUCTION AND OVERVIEW

The purpose of this chapter is to introduce you to the basics of allergy, what the practitioner should know in order to plan an effective integrative treatment strategy, and to provide an overview of some therapies that have been used successfully to treat different aspects of allergy. For the patient, an integrative approach usually means making lifestyle changes and being more attentive to what they allow inside their body and their home. For the practitioner, it means becoming more informed about allergy and treatment options in order to make better treatment decisions for each patient.

Millions of people worldwide endure the misery of allergies and suffer from their effects, seeking relief through conventional pharmacological remedies. However, most conventional remedies only treat the symptoms of allergies with antihistamines, decongestants or immunosuppressive medications, which, while offering welcome relief or even saving lives, do not treat the allergy itself. Untreated allergies can spread, worsen or cause other health problems. Also, reliance on drugs is always problematic, as most drugs have undesirable side effects.

One problem that has so far limited our ability to successfully treat allergy is what Dr Merv Garrett of the Australasian College of Nutritional and Environmental Medicine refers to as ‘labelling disease’.¹ Allergy is a multifactorial problem, attributable to so many causal factors and appearing in so many different ways that labelling all its manifestations as allergy can mislead the practitioner into a narrow pattern of diagnosis and treatment. Any diagnosis of allergy should include a thorough investigation of the influences on that particular case, and investigation into the likely effectiveness and appropriateness of different possible treatments.

DEFINITION OF TERMS

Most natural or complementary healthcare practitioners use the term ‘allergy’ to refer to situations in which the immune system overreacts to a normally harmless substance, causing an exaggerated sensitivity (hypersensitivity) to that substance. However, medical doctors and scientists often recognise only reactions that result from the activation of immunoglobulin E (IgE) antibodies as allergies—that is, the ‘classic’ allergy. People who experience allergic symptoms without the antibody reaction are said to have an intolerance or a hypersensitivity to a particular substance.

Some people, however, may have many of the symptoms of classical allergy, but reactions, which may occur hours or days after the exposure, involving little or no IgE. While these people may experience delayed skin reactions, their immediate skin reactions and blood tests for allergens may be negative or weak. More than a decade later, there is much wider recognition of the diversity of allergic responses, and of the fact that IgE-mediated responses do not account for all allergies, especially food allergies.²^–⁴

Because medical terminology must be precise in order to facilitate proper diagnosis and treatment, the following distinctions are made between allergy, sensitivity and intolerance.

• Allergy refers to the immune system’s hypersensitivity upon re-exposure to a sensitising agent, an allergen, which results in the release of inflammatory chemicals and development of various symptoms. Although the presence of IgE has traditionally been the marker of an allergy, the correct term applies to elevation of specific antibodies due to antigen stimulus.

• Sensitivity refers to adverse reactions in the body upon exposure to a sensitising agent in the environment. It does not involve antibodies, although it may involve other immunological processes. Most food and chemical reactions are sensitivities.

• Intolerance refers to the absence of a particular chemical (e.g. the enzyme lactase) or physiological process needed to digest a food substance, and the reaction is the result of non-immunological response of the body. Food intolerance is responsible for most adverse reactions to food, but it is not a true allergy; correcting the defect ends the symptoms.

BACKGROUND AND PREVALENCE

It is difficult to obtain solid, consistent, up-to-date statistics on allergy, but throughout the Western world, a significant rise in the incidence of allergy has been reported since the 1950s. A report released by the House of Lords Select Committee on Science and Technology in July 2007 stated that, ‘Allergy in the United Kingdom has now reached epidemic proportions, with new, more complex and potentially life threatening allergies’.⁵ Allergies are also on the rise in Australia, which has one of the highest rates in the world.

A study by the Australian Centre for Asthma Monitoring revealed that, ‘the number of Australians hospitalised for severe life-threatening allergic reactions has more than doubled in the past 15 years’, particularly among young children.⁶ In a lecture at the Onassis Foundation in Greece, Dr Daphne Tsitoura said that if something is not done to stem this growth, one in two Europeans will have allergies or allergy-related conditions by 2015.⁷

Food allergies, many of which do not fit the IgE-mediated reaction pattern, are on the rise globally. In 2001, the US Food and Drug Administration reported that ‘Only about 1.5 percent of adults and up to 6 percent of children younger than 3 years in the United States—about 4 million people—have a true food allergy, according to researchers who have examined the prevalence of food allergies’, but those statistics only included ‘classic’ allergies involving IgE. After surveying 14,948 people about seafood allergies, Sicherer and colleagues concluded that 2.3% of the general population had credible seafood allergy, suggesting that food allergies are much more prevalent than generally allowed for in US government statistics.⁸

The House of Lords report on allergy noted the adverse effects of allergy on quality of life, especially for children, and on school and workplace performance.⁵ In addition to this, allergy places an enormous economic burden on society. For these reasons alone, it is not to be taken lightly, even when the allergies are mild. Even more insidious are the less obvious and ‘hidden’ health effects of allergy. It makes life miserable for many sufferers, and has been implicated in a large number of diseases and disorders, including degenerative disease.

AETIOLOGY

Allergy means that the person’s body, for one reason or another, has lost the normal ability to cope appropriately with one or more substances. While heredity makes some people more susceptible to allergy than others, the causes of allergy and sensitivity are multifactorial. Specifically, genetic susceptibility and some dietary, environmental and lifestyle factors that break down or disrupt the individual’s immune system and barrier defences are in varying degrees responsible for the development and progress of allergy and sensitivity.

GENETIC INFLUENCES ON ALLERGY

An allergic predisposition or tendency is inherited, so allergy often runs in families. The age of onset of an allergic condition depends on the degree of inheritance: the stronger the genetic factor, the earlier in life is the probable onset. Genes do increase children’s risk of allergies, from 50–58% if one parent has allergies to 60–80% if both are affected. This risk seems to be higher if the mother has allergies. Even with a family history of allergy, however, a child may not develop allergies until later in life, or may never develop the condition, because allergy results from a combination of other factors that determine whether a person’s genetic susceptibility will be realised.

OTHER PARENTAL INFLUENCES ON INFANT ALLERGY

The development of allergy in people with or without a family history of allergies is usually triggered by pre-existing environmental influences that can affect a person even before birth. A mother with allergies can transmit them, and the antibodies against them, to her unborn child through the placenta, or after birth in the breast milk. A mother without allergies can transmit toxins, biochemicals resulting from chronic stress or trauma, or pathogens to the unborn child or infant in the same ways: via the placenta or through breastfeeding. This can set the stage within that child’s body for allergies. Some early influences on allergy are:

• serious parental disease or condition prior to conception or birth

• maternal exposure to harmful substances during pregnancy

• parental exposure to toxins prior to conception

• toxins in the child’s body resulting from disease (e.g. streptococcal infection as in strep throat, measles or chicken pox)

• maternal emotional or physiological trauma during pregnancy

• in utero and postnatal stress. Maternal stress, including parenting stresses and maternal depression, has been identified as a factor in early onset of asthma in children by age 3 years, and research suggests that the in utero environment, including maternal stress, affects atopy ⁹^–¹¹

• weakness of the child’s immune system due to infection, drugs, malnutrition etc.

ENVIRONMENTAL AND LIFESTYLE FACTORS

External factors can cause allergy in children and adults. In 1998, Dr Stephen Holgate wrote, in the Quarterly Journal of Medicine, ‘While ∼40% of the clinical expression of an allergic disorder can be accounted for by genetic factors, for these to be manifest there is an absolute requirement for interactions with environmental factors’.¹² The World Health Organization reported that, ‘convincing evidence demonstrates that a number of environmental factors—environmental tobacco smoke, poor indoor/outdoor climate and some allergens—contribute to the onset of allergic disease. Once the disease is established, these factors may also trigger symptoms’.¹³

Additional factors linked to the development of allergies include:

• diet—lack of variety, too much of one food, overeating or binge eating

• lack of breastfeeding

• early introduction of cow’s milk

• early introduction of solid food

• other factors such as hormonal imbalances, infections, metabolic diseases, seasons, altitude, nutritional imbalances, heredity and race.

In an article on preventing allergies, AB Becker of the University of Manitoba, Canada, wrote: ‘It is increasingly clear that gene-directed environmental manipulation of allergy in a multifaceted manner during a “window of opportunity” is critical in the primary prevention of allergy and allergic diseases like asthma’.¹⁴ The ‘window of opportunity’ for most people is in the first year of life, when a multifaceted preventive strategy can help develop the child’s resistance to allergies. Research suggests that in the first year of life, allergies may be prevented by:

• breastfeeding

• delayed introduction of cow’s milk

• delayed introduction of solid foods

• providing a wide variety of balanced dietary elements

• maternal and infant supplementation with probiotics.

(For more details, see below, under ‘Prevention’.)

THE TWO PATHWAYS TO ALLERGY

In general, some or all of the above-mentioned influences lead to allergies through one or both of two pathways:

• immune system hypersensitivity

• damage to the mucous membranes in the body’s natural defence barriers (gut, airways and skin).

Immune overreactivity

An immune system stressed by infection, stress or toxins can become hypersensitive and overreact to an otherwise safe substance. The first time this occurs, antibodies are produced that attach to basophils and mast cells embedded in the mucous membranes, creating sensitivity to that substance, but no allergic reaction. On the next exposure to that allergen, the antibodies ‘remember’ the substance, and stimulate release of chemicals, including histamines. Together with other cells also rushed to the affected site, these cause inflammation and the typical symptoms of allergy: coughing, sneezing, runny nose, swelling, itching and so on.

Failure of the mucous membranes

The cells of the mucous membranes lining the intestines, respiratory passages and skin are held together with ‘tight junctions’. When the membranes become irritated and inflamed, the tight junctions weaken, allowing food particles, bacteria or toxins to pass through the walls prematurely, which once again can lead to allergy.

One very important example of this is ‘leaky gut syndrome’, which researchers have shown to contribute to the development of allergies.¹⁵^–¹⁸ The mucous membrane lining of the gut wall can be compromised by:

• dysbiosis and/or faulty digestion

• infestation by bacteria, parasites, fungus, yeasts or protozoa

• chemical irritants or toxins

• inflammatory bowel conditions such as colitis, Crohn’s disease, coeliac disease (which may in turn be associated with hidden food allergies)

• chronic stress (leading to the over-release of certain chemicals and hormones)

• genetic or acquired enzyme deficiencies (e.g. lactose deficiency and coeliac disease).

DIAGNOSIS

The practitioner taking an integrative approach to allergies must be willing to look beyond the expected parameters of diagnosis, as allergies have a varied and complex pathology due to the interactions of so many different elements: physiology, psychology, genetic make-up, situation, family and environment. Not only do different people manifest the same kinds of allergies in different ways, and not only are they multifactorial in cause, but one must consider the possibility of cross-reactions, where sensitivity to one substance causes a person to be sensitive to ingredients in several other substances. For example, a person with an allergy to melons may also be allergic to other fruits or even to pollen because of certain similar ingredients. Assessment of cross-reactive food allergens requires careful history, testing and perhaps oral food challenges.¹⁹

Below is a simple but practical model for diagnosing allergies. Note the central role of the history in determining what might be causing the allergic symptoms.

HISTORY

The clinical pattern of allergies and food intolerances is often exposed in the history taken from the patient. The practitioner needs to identify childhood problems such as intolerance to milk feeding, frequent diagnosis of upper respiratory tract infections, ear infections, tonsillitis and sinusitis, which could all be due to dairy intolerance in particular. The history should include any history of eczema, information about dairy and wheat reactions, frequency and duration of reactions, possible or likely triggers, seasonal or other influences on reactions, such as presence of animals or certain locations, family history of any reactions or allergy disorders, age of onset of reactions or condition, and changes over time.

Through an examination of an infant’s dietary history, for instance, it is easy to establish a relationship between severe colic and cow’s milk, from which the practitioner can surmise that the colic is associated with cow’s milk intolerance (as reported by Iacono and colleagues ²⁰ and Hill & Hosking²¹) without resorting to distressing skin tests, and recommend dietary treatment.

Also ask about the emotional environment and the emotional context of reactions, as this can play a role in the onset and worsening of allergies.

History and other investigations are critical, even when the symptoms seem to indicate one kind of allergy. Food allergies or sensitivities, for instance, can lead to lung disease, asthma, eczema, and rhinitis, wheezing and other respiratory symptoms. Asthma can show up as food allergies and gastrointestinal symptoms. Food allergy or sensitivity is, in fact, often overlooked as a cause of asthma, especially because food allergies do not always show up in standard skin tests. Multiple chemical sensitivity with its complex combination of factors can also be missed by standard tests, and is usually diagnosed by history.²²

Dietary and environmental history

The purpose of taking a dietary and environmental history is to get an idea of which foods and toxins may be causing reactions. A week-long food diary can be adequate, showing where the food was bought, prepared and eaten, and any effects from eating the food. Include snacks, takeaway food, beverages and meals out.

Some reactions to food will be almost immediate, within an hour or two of consumption or even of contact with the food. These are usually obvious reactions such as stomach cramps, itching, vomiting or anaphylaxis, a severe and potentially fatal reaction which can involve light-headedness, swollen tongue or throat, difficulty breathing, fainting or facial swelling. Anaphylaxis usually occurs immediately or within 2 hours of food ingestion, and requires immediate emergency care. Other reactions may be ‘hidden’, occurring from 24 hours to days after ingestion, and this can make it difficult to relate them to particular foods. This is why a food diary is so important, as it can reveal otherwise hidden patterns of reaction. An elimination diet can be a useful diagnostic tool in this case (see below, under ‘Investigations’). Hidden reactions can include physiological reactions such as swollen lymph nodes or unexplained body aches, or they can be psychological, showing up as clusters of cognitive or behavioural problems.

Exposure to toxins

Clues to environmental factors are also to be found in the patterns of presentation of symptoms, and also in chemical testing, such as hair or urinary testing to identify environmental pollutants such as arsenic or mercury.²² Because a person can be allergic to just about anything, everything with which the person comes into contact should be considered, including common household chemicals such as:

• fluoride in toothpaste

• chlorine and/or fluoride in water (which can enter through the skin when bathing)

• chemical solvents and toxic fumes in building materials

• aluminium in deodorants

• nickel in jewellery

• latex in dish-washing gloves

• petrochemicals in many personal care products and cleaning products

• food additives and colours

• electromagnetic frequencies from computers, microwaves and mobile phones

• dust, which contains allergens such as mould, dust mites, pollen, debris from cockroaches, and household and animal dander

• toxins in sprays and treatments against cockroaches and ants

• formaldehyde in carpets, polyester clothing, spray starch and paper products

• Scotchgard™ on furniture

• poisons in fire retardants in clothing and upholstery.

SIGNS AND SYMPTOMS

How do you recognise an allergy? You look for signs, though you will only be able to see some for yourself, if any, so history is your primary diagnostic tool and can lead you to a correct diagnosis even when tests indicate to the contrary. Below are some signs and symptoms that can indicate allergy. You can include them in your consultation interviews or checklists.

First, suspect allergy whenever inflammation is present. If the allergic reaction is near the skin, you will often see all four cardinal signs of inflammation: pain, swelling, heat and redness. For example, hives will show up as a red, warm, painful and swollen rash. In the gut, allergies will cause inflammation in the gut lining, compromising nutrient absorption and digestion. Depending on where the reaction takes place, you will have different symptoms. Allergy can occur anywhere in the body, even in the brain.

There are two categories of allergy sufferers: those with obvious allergy symptoms and signs, and those with ‘hidden’ signs that may be easily overlooked. Signs of allergy include:

• nasal congestion, drippy nose, itchy teary eyes

• tender sinuses

• swelling of face, tongue or limbs

• skin rashes, eczema or hives

• coughing or wheezing

• dark, blue or black eye circles (sometimes called ‘allergic shiners’)

• crease at the bridge of the nose.

• wrinkles or abnormally puffy bags under the eyes

• a ‘spaced-out’ look

• bright red cheeks, nose tip or earlobes

• ‘wiggly’ or restless legs

• frequent nose rubbing

• frequent throat clearing or coughing

• a puffy look to face, hands and knuckles, ankles and lower leg

• eye problems—red, itching, burning, running, heavy puffy eyelids

• acne, acne rosacea, hives, eczema, dermatitis, boils, psoriasis

• sleep disturbances

• frequent colds and flu

• mental and behavioural—depression, irritability, agitation, mood swings, anxiety, anger, panic attacks, delusions, epilepsy, insomnia, restlessness, falling asleep at inappropriate times, or manifesting unusual behaviour

• persistent throat clearing, coughing

• burning or numbness of the face, arms, legs or feet, or a creepy crawly feeling under the skin.

INVESTIGATIONS

Most information will come from the history, and tests may also be administered, to identify or confirm major allergies and allow strategies to be precisely targeted. Various diagnostic procedures are available to test allergies and IgE-mediated allergies. Allopathic medicine uses various testing modalities to identify allergens and allergic reactions in sensitive individuals. Other diagnostic approaches include allergy symptom-rating questionnaire, food avoidance test, food challenge test, scratch test, elimination and challenge diet, rotation diet,²³ pulse difference test,^24,²⁵ patch test, skin prick test (SPT), radioallergosorbent test (RAST), provocative neutralisation testing, immunoglobulin studies (IgE, IgA, IgM, IgG) and IgE-specific antigen studies.

The most commonly performed allergy tests are the SPT, the RAST and the enzyme-linked immunosorbent assay (ELISA). They evaluate whether a person is producing specific IgE to ingested or inhaled allergens.

Scratch or prick test

A drop of concentrated antigen is placed on the skin, usually on the inner forearm, which is then pricked or scratched so that a minute amount of antigen is absorbed. The size of a wheal surrounded by erythema compared with the control indicates a response to a problem substance. Generally, a wheal diameter of 3 mm × 3 mm is considered positive. However, there are several complexities and pitfalls in interpreting SPTs. If a sensitive person has high IgE levels, the scratch or prick test can accurately determine allergy to pollens, moulds, dust, dust mite and animal dander. However, if IgE levels are low, a wheal may not develop even if the person tested is sensitive to these inhalants. There is no standard battery of allergens tested—the history guides which allergen extracts are used.

FIGURE 21.1 Positive prick test

When the scratch test is used for food testing, only food allergies for which the person has an extremely high IgE level will be uncovered. Because over 85% of food allergy is non-IgE mediated, this type of testing cannot give an accurate picture of a person’s food problems. The scratch test also cannot be used for testing chemicals, because most chemical reactions are not IgE mediated.

The test will not be effective if the person is taking antihistamines or antidepressants, as these will inhibit the skin reaction. The person must not take the test if on beta-blockers, as these will intensify the skin reaction, possibly leading to a severe reaction.

Patch test

The patch test is used to diagnose contact allergies. A patch with an antigen on it is applied to the skin and is left in place for 24–48 hours. Lesions, a rash, erythema or hardness of the skin under the patch indicate sensitivity to the test substance.

Blood tests

Several allergy testing methods use the person’s blood. The radioallergosorbent test (RAST) is a blood test in which IgE and IgG antibodies are labelled with a radioactive substance. The amount of antibody found in the blood in response to a given food, pollen, mould, dust and so on can be measured with a Geiger-counter type of instrument. RASTs are useful when SPTs cannot be performed. The RAST can test for sensitivities to a large number of substances in a short period of time. It works only with immunological antibodies; it cannot identify problem substances for which there is no antigen–antibody response, but it does have the advantage of measuring IgG antibodies, confirming an IgG-mediated immune response to milk in milk-intolerant individuals.²⁶

FIGURE 21.2 Positive patch test

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Tags: General Practice

Jun 3, 2017 | Posted by admin in GENERAL SURGERY | Comments Off

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