What is an allergic reaction?
Allergic or hypersensitive reaction is excessive sensitivity exhibited by your immune system to a conventionally harmless substance such as pollen, dust and certain foods. These substances are not dangerous in the majority of the people, but when they trigger allergic reactions, they are called allergens. Allergic reactions occur when the allergens contact the skin, are inhaled, swallowed or injected.
Allergic reactions are quite common and may happen seconds to hours after contact with the allergen. Though many allergic reactions are mild, others may be dangerous or life-threatening. They may be localized, involving a small part of the body or may affect a large area orthe whole body.
An allergic reaction begins with touching, inhaling or swallowing an allergen. In response to this trigger, the body starts making a type of protein called IgE or immunoglobulin E. IgE leads to the release of some chemicals (such as histamine) in the body. These chemicals cause the inflammatory symptoms of allergic reactions such as rash, itching and sneezing.
What are the typical symptoms of an allergic reaction?
The symptoms of allergic reactions vary depending upon whether the allergen came in contact with the skin, was inhaled, swallowed or injected.
The typical symptoms of allergic reactions are:
- Skin rash, redness or hives
- Running/blocked nose
- Swelling of lips and tongue
- Difficulty in breathing
- Wheezing or noisy breathing
- Itchy, red eyes
- Watering from the eyes
- Swelling of limbs
Although most allergic reactions are mild, some may need urgent medical intervention. Anaphylaxis is the most severe form of hypersensitive reactions. This is a medical emergency because it can lead to a sudden choking caused by narrowing of the wind-pipe. People with anaphylaxis have extreme difficulty in breathing, swelling, low blood pressure, bluish skin, and shock. It might be fatal if not treated.
How do you manage an allergic reaction?
The most effective management of allergic reactions is preventing them. Avoid the allergens whenever possible. For example, if you get rashes on wearing a certain type of jewellery or using certain cosmetics, you must avoid them. Similarly, if you are allergic to certain foods, it’s prudent to remove them from your diet.
- Avoiding allergens is important because repeated exposure may make the allergic reaction worse and more difficult to manage.
- Taking a shower or applying a cool compress may ease skin rash. It may also help to wash away any allergen clinging onto your skin.
- Do not rub yourself with a towel, pat dry and apply a gentle soothing gel or moisturizer.
- Wear breathable and loose clothes.
- Over-the-counter hydrocortisone or calamine lotion may help in relieving skin itching and burning.
- If your symptoms do not get better or become worse, you should seek medical help.
Patients who have a tendency to food allergies must be cautious while eating and preferably keep EpiPen with them, which is an automatic epinephrine injector used to prevent anaphylaxis in emergencies.
How long does an allergic reaction last?
Allergic reactions may last for varying lengths of time. They may take a few hours to a few days to disappear. If the exposure to the allergen continues, such as during a spring pollen season, allergic reactions may last for longer periods such as a few weeks to months.
Even with adequate treatment, some allergic reactions may take two to four weeks to go away.