Allergies in adults

Icon Health Screening / 28 May, 2020

What is an allergy?What is an allergy?

Allergies are exaggerated immune responses to environmental triggers known as allergens. Allergens are very common and can range from pollen, bee venom, pet dander to food.

Why are some allergies developed in adults?Why are some allergies developed in adults?

In some, the immune system reacts towards a foreign substance that does not cause a reaction in others. When that happens, antibodies are produced against the particular allergen. When they come into contact with the allergen, your immune system can cause reactions to your skin, sinuses, airways or digestive system. It is unknown why some individuals develop allergies and why some don’t.

Many allergies first occur as a child. However, an allergy can develop at any age regardless of your previous history with the allergen.

What are the signs and symptoms of allergies?What are the signs and symptoms of allergies?

Allergy symptoms depend largely on the type of allergen and which system is affected in the body.

A few of the examples listed below are commonly encountered allergens in our daily lives. Some of these allergies can overlap and cause a different type of reaction in certain people. Some heightened immune responses can also have unknown causes, such as atopic dermatitis (eczema) and chronic idiopathic urticaria condition.

  • Pollen, mites and other allergens associated with inhalation – Most commonly responsible for allergic rhinitis (also known as hay fever) which causes sneezing, runny nose, and watery and itchy eyes
  • Allergens associated with direct contact with skin, such as an insect bite – Insect bites and stings can cause an itchy rash, swelling and redness on the skin. In severe cases, allergens may cause an inflammatory reaction in the airway resulting in difficulty breathing, cough, chest tightness and, in certain cases, a potentially life-threatening reaction known as anaphylaxis.
  • Food allergens such as nuts, seafood, gluten, soy and food colouring – Food allergens most commonly cause swelling and a tingling sensation in facial areas such as lips and around the eyes, throat and tongue. These can also cause hives (a type of skin rash) and in severe cases result in an anaphylactic reaction.
  • Drug and medication-related allergens – Symptoms including an itchy skin rash and facial swelling are common with drug allergies, with some people also developing blisters and secondary skin infections. In severe cases, airway inflammatory reactions such as wheezing, difficulty in breathing and anaphylaxis may also occur.

Can allergies go away?Can allergies go away?

Most allergies cannot be cured. In the majority of cases, once antibodies are produced against certain allergens the immune reaction will always be triggered, even with mild exposure to the allergen. However, treatment can help to relieve allergy symptoms.

How are allergies managed?How are allergies managed?

The most important step in managing allergies is to remove the allergens causing the reaction. After that, focus is shifted to treating the symptoms that it has caused. The severity of allergies varies in different people and they can range from a minor irritation to anaphylaxis, which is a potentially life-threatening emergency. Management of symptoms depends on how severely the allergy affects you.

Mild and moderate cases

Oral medications such as antihistamine tablets can help relieve some mild symptoms such as swelling, itchy nose and skin rashes. If the symptoms subside after removal of the allergen, antihistamine can be stopped. If multiple flare up episodes occur, such as in cases of seasonal allergic rhinitis, long term antihistamines may be required. In cases of unknown allergens which cause chronic skin conditions, steroid treatment may be needed.

Severe cases

Severe anaphylactic reactions can cause light headedness, a rapid drop in blood pressure, weak pulse, severe difficulty in breathing and loss of consciousness. Immediate treatment is needed to reverse these symptoms or they will become life threatening. If an epipen is available, use it immediately and seek help. If you do not have access to epipen, a visit to the emergency department for adrenaline injection and stabilisation is often required.

Is there any way to prevent an allergic reaction from happening?Preventing allergic reactions

  1. Avoid known allergens – Once you experience a confirmed reaction towards an allergen, it is wise to avoid that allergen for the rest of your life. Although the allergic reaction that you had may have been mild, cumulative exposure can lead to a life-threatening reaction later in life. To avoid accidental exposure to the allergen, always pay attention to the alternative options you have. For example, food allergy sufferers can look for restaurants that cater for gluten free or other options.
  2. Keep a diary – For those who are unaware of the cause of your allergies, it is good to keep a record of what you have come into contact with or eaten on the day and a few days before you developed the allergy reaction. The fixed pattern of exposure can help you identify the potential allergen.
  3. Always inform those involved in your care about your allergy condition (e.g. healthcare workers) – When you see a doctor or a pharmacist for any prescription medicine or supplement, always inform them about your allergy condition so that an informed decision can be made.


For a full list of references, click here.
  1. Mayo Clinic. (2018). Allergies. Retrieved on 8 May 2020 from
  2. Ramsey, A. & Mustafa, SS. (2020). Allergy. Retrieved on 8 May 2020 from
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