6 Causes of Allergic Reactions on the Face

Contact dermatitis (rashes on the skin), tiny bumps, and hives are all signs of an allergic reaction. While these symptoms might not bother you on other parts of your body, they can be difficult to ignore on your face.

In this article, you will learn about contact dermatitis on the face, how to spot an allergic reaction, and when to seek medical attention.

Baby with rash on face

iStock / Getty Images Plus

What Are Allergies?

Allergies develop when your immune system misfires, triggering a reaction to everyday substances instead of viruses or bacteria. These reactions result from your body recognizing an allergen as a foreign and unwanted substance.

You can develop allergies to many different things, from pollens to pets. Some common allergens include:

What's an allergic reaction?

An allergic reaction is the body's response after exposure to an allergen. Your body makes antibodies against things it recognizes as harmful substances (allergens). These antibodies are called immunoglobulin E (IgE) and trigger the release of histamines and other inflammatory substances.


Histamines help cells in the immune system communicate and start the process of defending your body against harmful substances such as germs or allergens. Unfortunately, histamines can also cause symptoms of allergies, or allergic reactions, such as runny nose, sneezing, red itchy skin or hives.

Symptoms of Allergic Reaction

Allergic reactions can take many forms. Some allergy symptoms include sneezing, watery or puffy eyes, a red nose, and skin reactions ranging from redness to full-on hives.

Your body's inflammatory response to an allergen may begin with a rash that can progress to contact dermatitis or hives. Hives, or urticaria, can range from small to large red bumps that are very itchy and may become even worse if you scratch them.

In some cases (usually from skin exposure to an allergen), contact dermatitis may occur days, weeks or even months after the initial exposure. However, contact dermatitis from irritants like fragrances or chemicals is not considered an allergic reaction. This type of reaction usually appears with redness or rash but usually stops there.

What Is Anaphylaxis?

Severe allergic reactions can lead to swelling in your mouth or throat called anaphylaxis or anaphylactic shock. This response makes breathing difficult, includes a drop in blood pressure, and is a medical emergency requiring immediate treatment.


Other symptoms of anaphylaxis can include:

  • A warm sensation
  • Flushing
  • Red skin
  • Itching
  • Lightheadedness
  • Anxiety
  • Pain
  • Cramping
  • Vomiting
  • Diarrhea

Causes

Many foods, pollens, and medications can cause allergic reactions. Below are some of the most common allergens.

Animals and Insects

Allergies to animals or insects usually involve sensitivity to proteins found in animal skin cells (dander), saliva, and hair. Even when the animal isn't around, these proteins can linger and trigger a reaction. You may also develop a response to things like pollen and dust on a pet's fur.

Seasonal Allergies

Seasonal allergies can be caused by mold and pollens that tend to spike in numbers during certain times of the year. Some of the most common sources of seasonal allergies are:

  • Grass pollen (e.g., bahia, bermuda, blue)
  • Tree pollen (e.g., cedar, oak, pine)
  • Ragweed (e.g., short, giant, western)
  • Weeds (e.g., burning bush, tumbleweed, lamb's-quarters)

Some years may be worse for seasonal allergies, and things like wind and rainfall can also impact severity.

Food

You may be sensitive to many foods, but only a true allergy should trigger a visible reaction, such as a rash or hives on your face.

These eight foods make up about 90% of all food-related allergic reactions.

Medication

You can develop side effects or reactions to any medication, but several in particular are prone to triggering allergic reactions.

The most common medications associated with actual allergic reactions include:

  • Antibiotics, especially penicillins
  • Aspirin
  • Anti-inflammatory medications
  • Opiate medications
  • Some cancer drugs

Contact Dermatitis

Contact dermatitis (skin rash) can be caused by an irritant, an allergen, or both. Generally, skin rashes fall into one of two categories—irritant contact dermatitis and allergic contact dermatitis. It can be helpful to know what causes your reaction—allergy or irritant—since avoidance is the primary strategy for prevention.

Eczema

Eczema is a form of dermatitis called atopic dermatitis and is also triggered by an overreaction of the immune system. Similar to contact dermatitis, eczema can cause redness, itching, and the formation of a rash or small bumps. People with eczema often have several allergies, but triggers like fragrances in detergents, cold weather, and even some fabric types tend to be the most common.

Can You Be Allergic and Not Know It?

Not all allergic reactions have an obvious cause. A day in the sun could make your skin red, but that redness might also be from a medication you took. Sometimes symptoms of allergic reactions can be confused with symptoms of other conditions or exposures, especially if your symptoms are mild.


One way to tell whether it's an allergic reaction is to pay attention to the timing and consistency of the reaction. Reactions that appear within about an hour after exposure to a specific food or substance are likely allergic in nature.

When It’s an Emergency

Any severe allergic reaction is considered an emergency when accompanied by hives or anaphylaxis. Hives are often a sign of a more serious allergic reaction and are sometimes a red flag for anaphylaxis.

Anaphylaxis, on the other hand, disrupts breathing and can be fatal. If you have a history of anaphylactic reactions to allergens, you may want to make your close friends and family aware of your allergies and what you do to manage them.

Emergency Allergy Response

If you have severe allergies or a history of anaphylaxis, you and your healthcare provider should create an emergency plan. Initial treatment for anaphylaxis and severe allergic reactions is usually epinephrine. You can use a pre-loaded syringe called an EpiPen that you should always carry. Epinephrine might not completely resolve your allergic response, and 911 should be called either way.


Treatment

The best strategy for treating allergies is to avoid allergens. This requires allergy testing to pinpoint the exact allergens that could be triggering your reaction. Once you know your triggers, you can avoid them, but you should also have a plan to manage unforeseen exposures.

Medications to treat allergies include:

You and your healthcare provider should decide the best course of treatment based on your specific allergies and their severity.

Summary

Allergic reactions on the face can include skin rashes or redness, tiny bumps, or hives. The body's production of antibodies causes these symptoms after exposure to allergens, such as animals, food, or pollen. Severe allergic reactions can bring about anaphylaxis (swelling of the mouth and throat), making it difficult to breathe.

The best way to treat allergies is to avoid specific triggers, which you can determine through allergy testing. However, you should always have a plan to manage allergies in case of exposure.

A Word From Verywell

Redness or itching on your face isn't always a cause for alarm, but when caused by allergies, you need to be aware of your triggers and how to manage your symptoms. If you develop allergic reactions on your face, talk to your healthcare provider about what the cause may be and the best course of treatment.

Frequently Asked Questions

  • How long does an allergic reaction last?

    Allergic reactions can last for hours to weeks. Long-lasting reactions are common in allergies that produce hives or chronic reactions like eczema.

  • Can you stop an allergic reaction?

    Medications like antihistamines and steroids can help treat your allergic reaction, but symptoms from severe reactions may still last for weeks.

  • What are the most common types of allergies?

    Skin and seasonal pollen allergies are among the most common, but this can depend on age. Milk is the most common allergen for babies.

  • What causes allergies?

    Allergies are caused by a misfire of your immune system. When a normally harmless substance, like pollen, enters your body, your immune system confuses it with a serious threat and attacks. This attack results in inflammation, itching, and other problems.

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Allergy.

  2. Asthma and Allergy Foundation of America. Allergies.

  3. MedlinePlus. Histamines: the stuff allergies are made of.

  4. American College of Allergy, Asthma, & Immunology. Hives.

  5. National Eczema Association. Contact dermatitis.

  6. American Academy of Allergy, Asthma, & Immunology. Allergic reactions.

  7. American College of Allergy, Asthma, & Immunology. Pet allergies.

  8. American College of Allergy, Asthma, & Immunology. Seasonal allergies.

  9. American College of Allergy, Asthma, & Immunology. Food allergy.

  10. American College of Allergy, Asthma, & Immunology. Rashes.

  11. National Eczema Association. What is eczema?

  12. MedlinePlus. Allergic reactions.

  13. Yale Medicine. Allergic contact dermatitis.

By Rachael Zimlich, BSN, RN
 Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.