Allergy concept. woman sneezing using tissue in living room
Julie Hambleton
Julie Hambleton
July 21, 2023 ·  6 min read

Hidden Allergies You May Have and How to Spot Them

Allergies are not always easy to identify. While some allergic reactions are immediate and obvious, such as anaphylaxis when exposed to peanuts or bee stings, several hidden allergies tend to fly under the radar. These non-anaphylactic allergies can cause various symptoms that may be confusing, making it challenging to understand their root cause. Let’s explore some of these hidden allergies and discuss how to spot them.

Hidden Allergies You May Have and How to Spot Them

There are many different types of allergies, but the most common are food allergies, environmental allergies, and contact allergies. Food-related allergies may be obvious or hidden, depending on their severity. Some people experience mild symptoms such as a tingling mouth or a runny nose when eating certain foods, while others have an immediate reaction that can be life-threatening (anaphylaxis). Environmental allergens include pollen and dust mites; these allergens can cause sneezing and coughing as well as red eyes. Contact allergies tend to present themselves in the form of rashes and hives when exposed to certain materials like latex or nickel. (1)

Hidden allergies are sometimes hard to identify because they are not always accompanied by an immediate reaction. Hidden allergies can cause symptoms such as fatigue, difficulty sleeping, depression, and headaches.

Allergic reactions are caused by the body’s immune system overreacting to an allergen by releasing histamine and other chemicals that cause inflammation and other symptoms. This causes a chain reaction that can affect many body systems, including breathing, digestion, temperature regulation, and more. This is why other symptoms can include bloating, a runny nose, and more. Learning how to spot potential hidden allergies could help you to get a diagnosis and relief, faster. These are some of the more common “hidden” food allergies.

1. Food Allergies

Food allergies are not limited to severe reactions like an immediate rash or difficulty breathing. Many people experience hidden food allergies that manifest in more subtle ways. These allergies can lead to chronic symptoms such as bloating, gas, constipation, diarrhea, fatigue, headaches, or skin issues like eczema.

Spotting hidden food allergies can be tricky, but it’s helpful to keep a journal of what you eat and how you feel afterward. Look for patterns and notice if certain foods consistently trigger symptoms. Another effective way to identify food allergies is through an elimination diet, where you eliminate certain foods from your diet and reintroduce them one at a time, observing any changes in your symptoms.

The most common foods that people have “hidden” allergies to are dairy, eggs, wheat/gluten, soy, and corn. Because many people are unaware of their food allergies or sensitivities, these foods can sneak into our diets without us realizing it. For example, many foods contain hidden dairy ingredients like casein and whey protein isolates that may not be listed on the label. If you’re unsure whether a product contains any of these ingredients, check with the company before buying it. (2)

Read: 8 of The Most Dangerous Foods in the World

Don’t Forget Food Additives

Be sure also to consider food additives. There are a number of chemical ingredients often added to food that could be the real reason behind your discomfort. These include food dyes, preservatives, and flavor enhancers. These include (3):

  • Any white dyes, as well as carmine, annatto, tartrazine, and saffron
  • Preservatives such as benzoic acid and parabens, as well as sulfites found in wine, cured meats, and some dried fruits
  • MSG and Aspartame, as well as other flavor-enhancing agents

2. Environmental Allergies

Environmental allergies are not limited to seasonal allergens like pollen. Many people are unaware that they may be allergic to certain substances present in their everyday environment. For example, dust mites, animal dander, mold, or certain chemicals used in cleaning products can trigger allergic reactions. (4)

There are many seemingly harmless things, as well, that might be tracking allergens in your home. Indoor pollution can often be worse than outdoor pollution. This is problematic for those who try to “hide away” in the springtime. Vacuum cleaners are also known to spew allergens out of their exhaust, as their filters aren’t fine enough to trap them. You must buy a specific, high-efficiency one to avoid this problem. Cleaning products can also be irritants, depending on their ingredients. Look for natural ones and pay attention to your symptoms.

Be Careful Who You Invite Over

Finally, who you’re bringing into your home can also affect how many allergens get inside. Pets, beyond their fur, can bring in allergens after rolling around in the grass. Guests who come over can also track in pet hair, pollens, and more on their clothes and shoes.

To spot hidden environmental allergies, pay attention to when and where your symptoms occur. If you experience a runny nose, sneezing, itchy eyes, or difficulty breathing in specific environments, such as in a particular room or after cleaning, it may indicate an environmental allergy. Consulting with an allergist or having an allergy test can help identify the specific allergen causing your symptoms.

3. Medication Allergies

Medication allergies can also be hidden and may go unnoticed until an adverse reaction occurs. Not all medication allergies result in immediate, life-threatening reactions. Some may cause delayed symptoms like rashes, hives, or gastrointestinal issues. (5)

To spot hidden medication allergies, it is crucial to be observant and aware of any changes in your body after taking a new medication. If you experience any unexplained symptoms after starting a new treatment, consult with your healthcare provider immediately. They can help determine if you are having an allergic reaction and suggest suitable alternatives.

4. Chemical and Cosmetic Allergies

Chemicals and cosmetic products we use daily may contain ingredients that can trigger hidden allergies. Fragrances, preservatives, and certain dyes are common culprits. These hidden allergies can result in skin irritation, redness, rashes, or even allergic contact dermatitis. (6)

To spot hidden chemical and cosmetic allergies, be mindful of any changes in your skin or reactions after using new products. If you notice persistent skin issues or unexplained rashes, consider patch testing to identify specific allergens. Opting for fragrance-free or hypoallergenic products can also help reduce the risk of hidden allergies.

The Bottom Line

Hidden allergies are often difficult to spot and may cause chronic symptoms that go unnoticed. By paying close attention to our bodies and being mindful of any changes or patterns, we can better identify these hidden allergies. Keeping a journal, observing environmental triggers, consulting with healthcare professionals or allergists, and practicing elimination diets are all effective strategies to uncover hidden allergies and manage them effectively. Remember, it’s essential to seek professional advice when dealing with allergies to ensure accurate diagnosis and appropriate treatment.

Keep Reading: Why your grandparents had fewer food allergies, but you don’t


  1. People can have food sensitivities without noticeable symptoms – long-term consumption of food allergens may lead to behavior and mood changes.” The Conversation. Kumi Nagamoto-Combs. December 8, 2022.
  2. Top Allergens: Places Where They Hide.” Allergic Living
  3. Food Additives and Allergies/Intolerances.” Food Allergy
  4. Spotting Hidden Allergy Triggers.” WebMD. R. Morgan Griffin
  5. Medication Allergy.” Drugs
  6. Makeup Allergies: Symptoms and Treatment.” Medicine Net. Gary W. Cole, MD, FAAD