You’re not imagining it: Those new symptoms of congestion after spending time outdoors, or itchy throat after eating something you’ve ingested numerous times without incident could be signs that you’ve developed allergies.
“While most allergies present themselves during childhood, it’s not uncommon for adults to develop them later in life,” said Aneysa Sane, M.D., a Carilion Clinic allergist and immunologist. “And it’s not just environmental allergies that can suddenly pop up—it’s also possible to become allergic to foods you’ve eaten or skin products you’ve used for years without issue.”
What causes an allergic reaction?
Allergies can be triggered when you encounter a specific substance that your body mistakenly identifies as being harmful.
"In the case of an allergic reaction, our immune system produces antibodies called Immunoglobulin E (IgE) in response to a perceived threat," said Dr. Sane. "These antibodies attach themselves to certain cells, causing the cells to release multiple chemicals that contribute to the allergic response, which can result in pain, itchiness, watery eyes, runny nose and wheezing."
Most mild cases of allergic reactions can be managed by taking over-the-counter antihistamine medication, such as loratadine, fexofenadine or cetirizine. However, for some, taking antihistamines isn’t enough, and they can experience severe or life-threatening reactions (anaphylaxis), with symptoms that include:
- Swelling of the lips, tongue or throat
- Shortness of breath
- Nausea, vomiting or diarrhea
- Dizziness or fainting
- Low blood pressure
- Skin rashes, itching and hives
“Symptoms and reactions vary by person, and reactions can happen quickly or even be delayed,” adds Dr. Sane. “The severity of the reaction can even be different each time you come in contact with an allergen.”
Researchers still aren’t sure what causes the development of allergies. Moving to a new area can be a factor, especially if you move to a location that has more or different pollen than what you’ve previously been exposed to.
Family history can be another factor, however, just because a family member is allergic to shellfish doesn’t mean that their descendants would be allergic to shellfish as well—it would mean that their family members could be more likely to develop an allergy of any kind.
When should I see a doctor about my symptoms?
Most allergy symptoms can be managed by avoiding the allergen or taking medication. If symptoms become unmanageable, talk to your doctor about possible treatments, such as immunotherapy (allergy shots) and testing to determine what your allergy triggers are.
"It might not seem like a big deal to put up with the occasional runny nose, congestion or discomfort, but these kinds of symptoms can keep you from getting a good night's sleep and make you feel rundown in addition to dealing with the symptoms," adds Dr. Sane. "Your quality of life can go up significantly if you're able to pinpoint what exactly causes your body to react to be able to put preventative measures in place."