Insects, chemicals in sunscreen, and many other things can potentially trigger an allergic reaction whether you’re by the ocean or freshwater.

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Nothing ruins a relaxing day at the beach quicker than a flare-up of your allergy symptoms.

Allergies occur when your immune system perceives a normally harmless substance as dangerous and overreacts to it. Approximately 50 million people in the United States experience allergies each year.

Many people with pollen allergies find that they can breathe better near the coast. But that doesn’t mean beaches are entirely free of allergens.

Read on to learn about the most common causes of allergies at the beach and how they’re treated.

Many different things you encounter at a beach can potentially trigger an allergic reaction. Here are some of the most common potential causes.

Pollen

Pollen is one of the most common allergens. An allergen is a substance that triggers an allergic reaction. About 24 million people in the United States have seasonal allergies triggered by pollen from trees, grasses, and weeds.

Beaches tend to have less pollen than grassy or wooded areas, but ragweed pollen has been found in the air up to 400 miles from shore.

When pollen enters your body, it that can trigger symptoms like:

Sun allergy

A sun allergy, or solar urticaria, is a chronic condition that causes hives in parts of your skin exposed to sunlight. Hives are reddish areas of skin that may:

  • itch
  • sting
  • burn

It’s estimated that solar urticaria makes up less than 0.5% of cases of hives. The development of a sun allergy isn’t completely understood, but some medications like antibiotics may contribute to its development.

Sunscreen or lotion allergy

Sunscreen can contain ingredients that cause an allergic reaction when applied to your skin or when your skin is exposed to light.

The most common ingredient to cause allergies was para-aminobenzoic acid (PABA). The Food and Drug Administration (FDA) no longer classifies PABA as generally safe and effective for use in sunscreen.

A sunscreen allergy can cause a red and potentially itchy rash. Other symptoms might include:

Swimmer’s itch (cercarial dermatitis)

Swimmer’s itch is an allergic reaction to parasites released by snails in fresh or salt water that infect some birds and mammals. These parasites can burrow into your skin and cause a rash. It can cause symptoms minutes to days after swimming in contaminated water.

Your rash might:

  • tingle
  • burn
  • itch
  • develop small reddish pimples

Seabather’s itch (sea lice)

Seabather’s itch is also called seabather’s eruption or sea lice. It’s a burning rash that forms when jellyfish larvae are trapped between your skin and bathing suit.

Venom from the larvae or the larvae themselves can trigger an allergic reaction. Symptoms can develop right away or up to 24 hours later.

Insect allergies

According to the Asthma and Allergy Foundation of America (AAFA), medication, food, and insect stings are the most common causes of anaphylaxis, a potentially life threatening allergic reaction.

Insect sting anaphylaxis leads to about 100 deaths per year in the United States. But most people who get stung have mild reactions that cause symptoms like:

  • pain
  • redness
  • swelling
  • itching

It’s also possible to have allergies to insect bites, although, they’re less common.

Urushiol allergy

Urushiol is an oil found in some plants like:

When it gets on your skin, it causes an allergic rash and symptoms like bumps or blisters. About 80% to 90% of adults develop a rash when they come into contact with less than 50 micrograms — less than one grain of table salt.

Barbecue, tobacco, and campfire smoke

Smoke isn’t a known allergen, but breathing it in may worsen symptoms of allergic asthma. It can contribute to symptoms like:

Your allergies may worsen at the beach if you’re near one of your triggers like pollen.

According to the American College of Allergy Asthma and Immunology (ACAAI), beaches and mountains are excellent year-round vacation destinations for people with allergies. They tend to have less pollen and other substances that can trigger allergies than wooded or grassy areas.

But when it’s more humid — a reason many people go to the beach — allergens like dust mites may be worse as they thrive in humid environments.

Allergy symptoms are usually mild and resolve on their own or with supportive treatments. Serious allergic reactions require immediate medical attention.

Pollen allergy treatment

Avoiding pollen as much as possible can help minimize your symptoms. Other treatments that may help you manage your symptoms include:

Sun allergy treatment

Avoiding direct sunlight and protecting your skin with sunscreen can help prevent future outbreaks.

But if the rash is caused by the sunscreen interacting with UV light, causing contact dermatitis, stop use.

It’s recommended that you put a small amount of sunscreen on your body before using it everywhere to see if you have a reaction. If you do, do not use that sunscreen.

Over-the-counter or prescription antihistamines may reduce hives. They may also recommend phototherapy, where your skin is exposed to light for short periods to build a tolerance.

Sunscreen allergy treatment

Switching sunscreen formulas can help you avoid a future reaction. Titanium dioxide and zinc oxide are not known to cause an allergic reaction.

If you have a moderate to severe reaction, it can be treated similarly to other allergic skin reactions. Topical or oral steroids can help reduce inflammation, and oral antihistamines can help with itching.

Swimmer’s itch treatment

It’s important to avoid scratching the rash to reduce your chances of getting an infection. Treatments that may reduce symptoms include:

Sea lice treatment

Sea lice can usually be treated at home with over-the-counter treatments like hydrocortisone cream.

It’s a good idea to remove your bathing suit as soon as possible to reduce the amount of time the larvae and venom are in contact with your skin. Applying diluted vinegar to the affected areas may also prevent further irritation.

Insect sting or bite treatment

Mild insect bites and stings can be treated with similar treatments as other allergic reactions. It’s critical to get immediate medical attention if you have signs of anaphylaxis like a fast heartbeat or trouble breathing.

Urushiol treatment

If you’re exposed to a plant that contains urushiol, it’s a good idea to immediately rinse your skin with soap and water.

After washing, you may be able to relieve symptoms with:

Contact a doctor if home remedies are not effective. They may recommend a prescription-strength topical steroid.

It’s critical to get immediate medical attention if you have a rash on your face or genitals.

Breathing in too much smoke

If smoke is contributing to your symptoms, it’s best to remove yourself from the source. Using a quick-relief inhaler, if you have one, can help open your airways.

It’s a good idea to contact an allergist if your allergies are frequently making you sick or if they’re causing reoccurring problems. An allergist can:

  • develop a treatment plan
  • perform allergy testing
  • educate you on how to avoid your triggers
  • prescribe medications
  • give allergy shots
Anaphylactic shock, a medical emergency

It’s critical to call emergency medical services or go to the nearest emergency room if you have symptoms of anaphylactic shock, like:

Tips to help prevent allergies at the beach include:

  • protect yourself from the sun with sunglasses, sunscreen, and clothing that covers your arms and legs
  • stay on trails to avoid accidental contact with poisonous plants
  • find a beach away from grasses or other plants that may trigger a pollen allergy
  • check your local pollen forecast
  • look for BAPA-free or mineral sunscreens and change formulas if a sunscreen irritates you
  • try a new sunscreen on a small patch of skin before your whole body (wait 24 hours to see if there will be a reaction) before going to the beach
  • check for warnings of sea lice or swimmer’s lice from lifeguard stations
  • change your bathing suit soon after getting out of the water and wash off with fresh water
  • avoid sugary or meat products that might attract insects, like ants or wasps
  • stay upwind from smoke

Beaches generally have less pollen than areas with lots of grass, flowers, or trees. But it’s still possible for pollen at some beaches to trigger your allergy symptoms.

Beaches can contain other potential allergy triggers as well, like insects, the sun, and organisms in the water. If your allergies regularly bother you, you may benefit from visiting an allergist.