Allergies are essentially an abnormal and exaggerated response of the body to a foreign body, otherwise known as an antigen. This causes the immune system to go into overdrive – eliciting a response that works against ourselves.

The job of our immune system is to recognize and defend the body against harmful bacteria and substances. While a normal person’s immune system will view a specific substance as harmless – someone with an allergy to it will see it as a threat – triggering the immune system to attack it in response.

While the majority of allergic reactions are mild to moderate and do not cause any major problems, there are instances where things might take a drastic turn and quickly turn fatal.

Taking the time to better understand your allergies and seeking proper treatment is thus the first step to preventing any severe allergies and flareups.

Why People Get Allergies

The reasons as to why some people are more susceptible to allergies are not known, but there is evidence to show that it starts in your genes.

A child with one allergic parent has a 33% chance of developing allergies, and this goes up to 70% if there are two allergic parents.

Even so, it seems that allergic reactions are mostly triggered due to environmental factors – and the keyword here is exposure. In fact, the very first time that your immune system sees an antigen, it merely produces antibodies that are designed to target and attack it. While this normally doesn’t cause any problems, it is the second time that becomes the tipping point where you end up getting a reaction.

People with an allergy develop a specific antibody called immunoglobulin E, or IgE to particular antigens. These IgE are found on the surface of the body’s mast cells, and the subsequent binding of specific antigens to these IgE leads to a process involving the release of an inflammatory chemical called histamine from the mast cells. Since allergic individuals often produce it in larger quantities than the average person, this causes inflammation – a common symptom seen in allergic reactions.

The symptoms of an allergic reaction can range from mild to severe, including:

• Stuffy nose due to increased mucus production
• Itching that is localized or on the whole body
• Puffy, swollen eyelids
• Sneezing
• Coughing
• Localized swelling and inflammation

In severe cases, symptoms also include:

• Diarrhea
• Nausea or vomiting
• Fatigue
• Dizziness
• Difficulty swallowing or breathing
• Tightness in the chest
• Heart palpitations

Once the white blood cells produce an antibody specific to the antigen, “sensitization” occurs – where the immune system learns to respond in the same exaggerated manner with subsequent exposures to the allergen.

Common Types of Allergies

Allergies come in many different forms and affect different organs in the body, but the most common ones are:

• Contact dermatitis (caused by coming into direct contact with a substance)
• Food allergies (occurs due to an immune reaction to particular food proteins)
• Drug allergies (occurs due to an immune reaction to medications such as antibiotics, aspirin and other painkillers)
• Allergic rhinitis (also known as hay fever, this type mainly affects the nose and is considered to be a seasonal allergy)

Things that cause allergies can include anything from metals, fragrances, latex gloves, dairy products, pet dander, dust mites, tobacco smoke, and even insect stings. Certain people can even get an allergic reaction from sniffing certain odors.

Contact Dermatitis

The most common contact allergies that dermatologists see and treat are allergic contact dermatitis and irritant contact dermatitis – both cause an itchy rash that follows after being in contact with allergens in the environment.

Allergic contact dermatitis symptoms are often delayed (48 – 120 hours after exposure), while irritant contact dermatitis can happen within a matter of hours. While allergic contact dermatitis requires “sensitization” to take place, irritant contact dermatitis is more of an inflammatory response to an external stimulus.

Given that over 8% of adults will suffer from contact dermatitis at some point, with some occupations being more susceptible than others – hairdressers, medical workers, construction workers, and even chefs can often find themselves having a reaction while working with certain tools and chemicals daily.

Regardless of which type you have, getting diagnosed by a doctor or dermatologist is the first step forward, as many of these reactions can be mistaken for a harmless rash that results in delayed treatment.

Food and Drug Allergies

Food and drug allergies have the most potential to become a serious condition since they often involve the allergen being absorbed directly by the body and into the bloodstream, where symptoms can develop much quicker.

The most common food allergens which make up 90% of all food allergies are cow’s milk, eggs, peanuts, shellfish, soy, tree nuts, and wheat. Even the smallest amount can trigger a reaction within seconds, which is why special attention needs to be taken for those who have a known trigger.

Food is also the most common trigger for anaphylaxis in Singapore, accounting for 63% of adults and 44.8% of children who were sent to the emergency department in Singapore for this serious allergic reaction¹.

In one Singapore survey, it was shown that those born in Asia have a lower risk of peanut and tree nut allergies compared to those in Western countries, irrespective of their ethnicity².

Dust mite allergies are also extremely common in Singapore, where being in isolation and staying home can increase the chances of a severe reaction if you do not take the necessary precautions.

A study also showed that allergic reactions and responses can also increase with stress exposure³, which is why stress management is even more important for those who are prone to allergic reactions.

Although allergies are more common in children, they are more likely to outgrow their allergy as they grow older when compared to adults. The onset for adult allergies can happen anytime from your 20s to 30s, and even during your 70s and 80s. Treatment thus becomes vital in order to successfully manage allergies in the long run.

When Allergies Become Serious: Anaphylaxis

Although rare, some people may experience a severe allergic reaction known as anaphylaxis. It is a potentially life-threatening allergic reaction that can affect multiple organs and can cause the following symptoms:

• Itching or flushing of the face
• Swelling of the tongue and/or throat
• Increased heart rate
• Nausea and/or vomiting
• Abdominal discomfort and/or diarrhea
• Shortness of breath, wheezing, and/or coughing
• Low blood pressure, dizziness, and/or shock

Anaphylaxis is considered to be an emergency that causes the blood vessels to dilate excessively – causing a significant drop in blood pressure and preventing adequate blood flow to the vital organs in the body. The condition often develops within seconds after exposure and can lead to a loss of consciousness, cardiac arrest, and even death.

A 2014 study found that peanut was the top cause of anaphylaxis in a Singapore paediatric emergency centre⁴. Anaphylaxis from consuming dust mite-contaminated flour has also been reported in Singapore when it is stored for long periods⁵, and the warm and humid climate becomes the perfect breeding ground for the allergen.

Epinephrine is the medication that is used to treat anaphylaxis, and patients with a high chance of getting the condition are advised to carry two auto-injectors for immediate injection into the body that can potentially save your life.

Allergies can also trigger skin problems such as atopic dermatitis (eczema) and urticaria (hives), or even asthma – which can all be extremely disruptive to daily life. Intense swelling with hives can also lead to a condition known as angioedema – a severe condition that requires timely treatment.

Other Severe Reactions That Can Occur

There are also serious, although more rare, allergic reactions that can also occur with certain drugs:

• Stevens-Johnson Syndrome (SJS) – primarily affects the skin and mucous membranes; causing the skin to blister and peel. Blisters can also form inside the body that can make it hard to eat, swallow, or urinate. It can affect the skin, nose, mouth, genitals, and eyes.
• Toxic Epidermal Necrolysis (TEN) – shows similar symptoms to SJS, although in a more severe form.
• Drug Reaction (or Rash) with Eosinophilia and Systemic Symptoms (DRESS) or Drug Hypersensitive Syndrome (DHS) – affects multiple organs such as the lungs, liver, and kidneys, and involves both an immune and systemic reaction. It has a relatively later onset than SJS and TEN.

Recognized as severe adverse cutaneous drug reactions – SJS and TEN are often seen as part of the same spectrum, diagnosed by determining the level of body surface area (BSA) detachment. SJS is identified when 10% of BSA detachment is present, and 30% in the case of TEN.

Beginning with a persistent fever, body aches, and flu-like symptoms, patients are often left covered in red spots and skin that blisters and peels – leaving raw areas (erosions) on the skin that is painful and feels similar to a burn.

These serious manifestations of an allergic reaction can be very dangerous if not treated promptly and can lead to “acute skin failure” – a condition that is comparable to other major organ failures.

With the potential of blindness, lung problems, infection, and even death – it is critical to get them treated as early as possible.

How Allergies are Diagnosed

Doctors and dermatologist specialists often use patch tests or skin prick tests to identify specific allergens, or may administer a blood test to look for the presence of specific IgE antibodies in the case of a food or drug allergy, or any delayed reactions such as DRESS.

To attain a more accurate diagnosis, a thorough historical analysis should also be conducted, allowing your doctors to better understand your work environment, the products you use, and any medications that you may be currently on that could be causing a reaction. 

How to Treat Allergies

First-line therapy for any type of allergy reaction is always prevention. This means identifying and actively avoiding your allergens and triggers – similar to what is recommended in the case of eczema and psoriasis.

Then there are a variety of oral and topical medications such as antihistamines, corticosteroids, mast-cell stabilizers, decongestants, and epinephrine (e.g. EpiPen) which can provide relief of the symptoms such as itching, inflammation and help suppress the overactivity of the immune system.

In the case of contact allergies, dermatologists often administer a mid-to-high potency topical steroid, and for more chronic and severe cases, systemic steroids may provide faster relief. 

All treatments come with side effects, which is why it is highly recommended to seek guidance from a dermatologist – ensure that you find a doctor who deeply understands your needs and preferences and can advise you on the best treatment that matches your goals!

Key Takeaways

There is growing evidence showing the increase of allergies worldwide.

Adding on to the long list of symptoms, allergies can also trigger skin reactions that can cause our skin to itch, bleed, and scar. At Angeline Yong Dermatology, we are proud to offer a holistic treatment plan that starts with allergy evaluation and testing, followed by a combination of topical and oral medications.

We may also utilize new-class biologics – made from animal or human proteins that are completely safe and compatible with humans, to target specific biologic pathways that cause hypersensitivity or inflammation.

Dr. Angeline Yong is also the one behind the core AYD skincare range that is designed to be customizable to every individual’s skin type, needs, and goals. A skin dermatologist with over 15 years of experience treating the body from head to toe, Dr. Angeline is a huge advocate of putting skin health at the forefront and protecting your most important barrier against harmful radicals and diseases.

Many complications can occur with what may seem like a normal, harmless allergic reaction. If your symptoms are worsening with no sign of improvements, or you are experiencing severe symptoms like wheezing and dizziness – this is a clear sign that your allergy is something far more serious and you should not hesitate to book an appointment with us as soon as possible!

Note: Food and drug allergies can be a fatal condition that requires immediate medical attention and treatment. Considered to be an essential treatment – our clinic will still be open during the circuit breaker period; however, we will only be providing essential services that are in line with government requirements.

Please take note that cosmetic treatments will not be offered during this time as we will be focusing solely on medical and surgical treatments that are considered essential.

References:
1. Thong BY, Cheng YK, Leong KP, Tang CY, Chng HH. Anaphylaxis in adults referred to a clinical immunology/allergy centre in Singapore. Singapore Med J. 2005;46:529–34. 
2. Sicherer SH, Furlong TJ, Maes HH, Desnick RJ, Sampson HA, Gelb BD. Genetics of peanut allergy: a twin study. J Allergy Clin Immunol. 2000;106:53–56. 
3. Liu LY, Coe CL, Swenson CA, Kelly EA, Kita H, Busse WW. School examinations enhance airway inflammation to antigen challenge.Am J Respir Crit Care Med. 2002 Apr 15;165(8):1062–1067. 
4. Sicherer SH, Furlong TJ, Maes HH, Desnick RJ, Sampson HA, Gelb BD. Genetics of peanut allergy: a twin study.J Allergy Clin Immunol. 2000;106:53–56. 
5. Liew WK, Chiang WC, Goh AE, et al. Paediatric anaphylaxis in a Singaporean children cohort: changing food allergy triggers over time. Asia Pacific allergy. 2013;3:29–34. 
6. Marogna M, Spadolini I, Massolo A, Canonica GW, Passalacqua G. Randomized controlled open study of sublingual immunotherapy for respiratory allergy in real-life: clinical efficacy and more. 2004 Nov;59(11):1205–1210.