8 Rare Allergies To Know

Common allergies are pollen, peanuts, mold, and animal dander, but rare food allergies to allergens like beer and coffee beans exist. These aren't the only rare allergens; for example, one of the most uncommon things to be allergic to is water.

Some people's skin might also be hypersensitive to other factors, such as cold weather or their sweat. Even with rare allergies and sensitivities like these, it's also rare not to have allergies—millions of Americans are allergic to something. Here's what you need to know.

1. Coffee Beans

An allergy to coffee beans is very rare. There aren't many large-scale studies about this allergy, but one case report indicated that a person was allergic to the particles from roasted coffee beans.

The individual had airborne allergic contact dermatitis, meaning their allergic reaction was skin-related after exposure to the coffee beans. The person experienced skin redness and developed papules on their face, neck, hands, and arms.

Of note, people might mistake a caffeine intolerance for a coffee allergy. Caffeine intolerances are more common and don't involve an immune response. People will usually experience abdominal pain and other gastrointestinal symptoms when consuming high amounts of caffeine from different sources, whether from coffee, tea, or soda.

2. Beer

An allergy to beer is also rare; few reported cases exist. Some available evidence about beer allergies has suggested potential allergens include proteins from barley, maize, and hops.

Of note, while some people may have allergies to beer, they may not have to avoid all options. Researchers noted that some people with the allergy may be able to consume certain types of beer without any reactions.

3. Red Meat

A red meat allergy is also known as tick bite meat allergy or alpha-gal syndrome. Alpha-gal is a type of sugar molecule found in Lone Star tick saliva. People bit by Lone Star ticks are at risk for developing an allergy or sensitivity to alpha-gal.

People with this allergy can have potentially life-threatening reactions after consuming red animal meat, including pork, beef, lamb, and venison. Cow milk and gelatin—a common coating for some oral medications—may also trigger a reaction.

Typical symptoms of an allergic reaction appear two to six hours after consuming alpha-gal. Cases can be mild to severe. If you have this allergy, you may not necessarily react each time you consume products with alpha-gal, but in severe cases, it can cause anaphylaxis.

4. Wine

Some people can be allergic to red wine and other types of wine. Itchy eyes, a stuffy or runny nose, and a red, itchy rash are common wine allergy symptoms. People with an allergic condition, such as asthma or hay fever, may be more likely to experience an allergy to wine.

It is unclear what triggers an allergic reaction to wine. Some people may be allergic to the proteins in grapes. Others may react to yeast or other ingredients for processing and cleaning wine. Proteins from insects that can contaminate crushed grapes may also trigger a reaction.

5. Water

Water is essential for your health: About 60% of your body is made up of water, which helps flush out toxins and regulates body temperature. ^{However, some} people can break out in hives and rashes after touching water. This water allergy is known as aquagenic urticaria.

Scientists don't know what causes aquagenic urticaria. Some reported cases show a potential family history of the allergy, and experts have yet to identify specific genes linked to this condition.

Based on reported cases, reactions happen only when there is direct skin contact. Any type of water can trigger this allergy, including:

• Distilled (purified) water
• Rainwater
• Saltwater
• Sweat
• Tap water
• Tears

6. Sunlight

Sunlight and other sources of ultraviolet (UV) light can cause a hypersensitive immune response that worsens several skin conditions. These photosensitive conditions are known as photodermatoses, and symptoms will vary by the condition.

Some examples of photodermatoses include:

• Polymorphic light eruption (PMLE): This is the most common type of photodermatosis. It has been linked to several gene mutations.
• Solar urticaria: A person with this condition develops a recurring skin rash after a few minutes of sunlight exposure. It typically starts in early adulthood, though it is unclear why some people can develop it.
• Photoallergic dermatitis: This is a very rare eczema-like rash that produces redness and scaling. Light-sensitive chemicals found in sunscreen can react with sunlight and trigger symptoms.

7. Sweat

While a sweat allergy may seem unlikely, it's not unheard of. Some people develop pin-sized, raised bumps (weals) when sweating—this condition is called cholinergic urticaria. If you have atopic dermatitis (AD), a type of eczema or chronic inflammatory skin disease, you may have worsening itchy rashes when sweating.

While sweat allergy causes are unclear, people with AD or cholinergic urticaria may also be overly sensitive to their own sweat. The release of water, sodium, and toxins and skin pH changes can trigger an allergic reaction in some people, particularly if they have existing skin damage or rashes from AD.

Another factor could be differences in skin microbiome—the bacteria, fungi, and other microorganisms that naturally live on your skin. There are likely other sweat allergens that scientists have yet to discover.

8. Cold Temperatures

Although very rare, it is possible to be allergic to the cold. Cold urticaria, also known as cold urticaria, has common symptoms, including hives, which can appear as red, itchy welts (bumps) or swelling on the skin. Hives can also develop on soft tissue areas, like the tongue or throat.

Symptoms usually begin within one to five minutes after exposure to the cold and may go away within one hour or longer. In severe cases, it can be potentially life-threatening when anaphylaxis happens.

The exact cause is unknown, but some people may be genetically predisposed to it. They may have certain gene mutations that lead the immune system to overreact to colder temperatures, resulting in inflammation in the skin. Common allergy triggers also include:

• Air conditioning
• Cold foods and beverages
• Cold showers or swims
• Cold winds
• Winter weather

Allergies vs. Hypersensitivities

In some cases, you may hear the terms allergies and hypersensitivities used interchangeably. That may be in part because, essentially, allergic reactions are also known as hypersensitivity reactions.

In addition, allergies are a subset of hypersensitivity reactions, ranging from type I to type IV reactions. For example, food allergies fall under type I hypersensitivity reactions. Type I hypersensitivity reactions refer to reactions that happen right away—within minutes of contact with an allergen.

When To See a Healthcare Provider

Visit a healthcare provider for proper diagnosis and treatment if you have an allergy or hypersensitivity. Your treatment will depend on the severity of your symptoms and your allergy overall.

You can usually manage symptoms like a stuffy or runny nose and itchy throat with over-the-counter medications, like antihistamines used for seasonal allergies. Mild reactions can worsen unexpectedly, so seeing a healthcare provider is still important.

For more serious reactions, a healthcare provider may prescribe steroid medications to help reduce inflammation. Depending on your allergy type and severity, a healthcare provider may also suggest immunotherapy.

While immunotherapy is typically a treatment for allergies to pets or pollen, it's a treatment sometimes used for food allergies. In this treatment, you consume a small amount of the food allergen under the supervision of an allergist. The goal is to build your tolerance to the food and reduce your immune system's sensitivity.

In addition, consider getting an allergy test—such as a skin prick test—to know your exact triggers. A skin prick test checks how your skin (usually your forearm) reacts to an allergen like pollen and certain foods.

When To Seek Immediate Medical Care

Seek immediate medical attention if you experience severe, life-threatening symptoms. Signs of anaphylaxis usually affect more than one part of the body. They can include:

• Diarrhea
• Difficulty breathing
• Hives all over your body
• Lightheadedness
• A swollen throat
• Vomiting
• Wheezing

In an emergency, a healthcare provider will administer an epinephrine shot, also known as adrenaline. This drug helps counteract the effects of a severe allergic reaction by boosting blood pressure and relaxing muscles along the airway.

A provider may prescribe a supply of epinephrine autoinjectors you can have on hand in case of an emergency if you are at known risk of a serious allergy. Talk with a provider about how to use it, and be sure people in close contact with you are prepared to use it as well.

A Quick Review

Although uncommon and sometimes rare, people can be allergic to everyday foods, like wine or red meat. In addition, sunlight, water, and other hypersensitivities can trigger skin reactions in people with rare conditions.

Whether you think you have allergies, hypersensitivities, or both, see a healthcare provider for diagnosis and the proper treatment plan. It's also essential to seek emergency care if you have signs of anaphylaxis.