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An allergy is an immunogenic response of the body to an otherwise harmless substance that is mistakenly perceived as a pathogenic invader or health threat.
An allergic reaction occurs when the body reacts abnormally to an otherwise normal substance that is introduced to the immune system by skin contact, ingestion, inhalation, or injection. The substances that induce such adverse reactions in allergic individuals are known as allergens or triggers. The genetic tendency to have allergic reactions is called atopy.
The immune system perceives the allergen as a foreign threat and releases inflammatory chemicals to defeat or destroy the invader. These chemicals can cause discomforting symptoms in the skin, ears, throat, eyes, nose, mouth, or lungs.
What Happens During an Allergy?
When the body comes in contact with an allergic substance, the immune system reacts by releasing IgE antibodies to combat the trigger. These antibodies, in turn, stimulate some of the cells to release chemicals, such as histamine, into the bloodstream.
It is this histamine that causes allergic symptoms in the skin, nose, lungs, eyes, gastrointestinal tract, or throat. The body will undergo a similar reaction every time it is exposed to a trigger or allergen.
Types of Allergic Reactions
The onset of an allergic reaction can vary depending upon the person’s genes and part of the body affected.
a. Immediate allergic reactions
If the allergy symptoms appear within minutes of exposure to the trigger, it is referred to as an immediate allergic reaction.
b. Delayed or late-phase allergic reactions
Sometimes the body may not react instantaneously to an allergen and may take 2–6 hours or even longer to mount a counterattack.
As a result, the symptoms will begin to show only a few hours after initial contact with the allergen. This is known as a delayed or late-phase allergic reaction.
What Causes Allergies?
Allergic tendencies are usually passed down across generations and are therefore hereditary. However, one will inherit only the likelihood to develop an allergy, not the allergy itself.
In other words, it is not the particular allergy that is passed down but the tendency to develop an allergic reaction that is genetically transferred from parents to children.
Signs and Symptoms of an Allergy
An allergic reaction can manifest differently in different people, depending upon the trigger and mode of contact with the trigger.
That said, some allergy symptoms are more commonly reported than others. These symptoms include:
- Allergic rhinitis, which manifests as a blocked or runny nose accompanied by itchiness in the nose and sneezing
- Conjunctivitis, which causes watery eyes with itchiness and redness
- Cough accompanied by shortness of breath, chest tightness, and wheezing
- Hives, which causes a red rash on the skin that is itchy and raised
- Swelling in the eyes, face, tongue, or lips
- Diarrhea, tummy ache, nausea, or vomiting
- Cracked skin that is red and dry
Treatment for Allergies
By and large, allergies cannot be cured but the symptoms can be managed. This is done primarily by staying away from the offending substance that triggers the allergic response in your body – a technique called “avoidance.”
The doctor may also prescribe certain medications or allergy shots to reduce the severity and frequency of allergy symptoms.
1. Allergy medications
Some of the commonly used allergy medications include:
2. Allergy shots (immunotherapy)
The administration of allergy shots is part of immunotherapy, which is a treatment modality designed to increase your body’s tolerance for specific allergens gradually.
Diagnosing an Allergy
Diagnosing an allergy typically involves the following steps:
- The doctor will first inquire about your symptoms, medical history, and any unusual substance that you may have ingested, inhaled, or touched in the recent past.
- This is followed by a thorough physical checkup to rule out other conditions and check for symptoms that are consistent with an allergic response.
- The final step is to conduct a blood test and skin test to identify or confirm suspected allergens.
What Is an Anaphylactic Shock?
Anaphylaxis, or anaphylactic shock, is a potentially fatal form of allergic response wherein your entire body reacts to the allergen, causing inflammation in different parts of the body.
Anaphylaxis can manifest differently in different people, but some of the most commonly reported symptoms include:
- Closing up of your airways, leading to extreme breathing difficulty
- A sudden drop in blood pressure
- Wheezing or tightness in the chest along with coughing and difficulty in breathing
- Weakened heartbeat, fainting spell, dizziness
- Having trouble swallowing due to the swollen throat or mouth tissues
- Feeling overly warm, having hives or itchiness, flushing
- Stomach cramps, diarrhea, vomiting
Risk Factors for Allergies
The following factors can predispose you to develop an allergy:
- If you have compromised immunity
- If you have preexisting asthma
- If asthma or allergies, such as eczema, hay fever, and hives, run in your family
- If you are young
Complications Associated With Allergies
Allergies are quite distressing themselves and they increase the risk of other more serious health issues if not managed properly.
The complications associated with a severe or poorly managed case of allergy include allergic asthma (or hay fever) and aspergillosis (a fungal infection in the lungs or sinuses). (2)
When to See a Doctor
It is recommended that you get yourself evaluated by a doctor if you have the slightest inkling of an allergy. The first step in managing an allergy is to identify its cause.
Once the doctor has identified the allergens, he/she will suggest the necessary precautions to minimize your exposure to them. The doctor may also recommend certain OTC anti-allergens if he/she feels that your condition calls for it.
If the preliminary medications fail to provide relief, you must inform your doctor, who may then prescribe a more suitable alternative.
If you have a history of severe allergy, you are advised to work closely with your doctor to come up with a proper management plan that aims to avoid allergens and prevent future anaphylactic shocks.
To manage allergies, the first step is to identify and avoid known triggers to the best of your abilities. The next steps include considering therapies such as preventative or emergency medications and allergen immunotherapy (allergy shots), if applicable.
Although there is no permanent cure for allergies, there have been cases where the condition has resolved on its own only to resurface again years later.