Whether you are hiking in the woods, gardening, or swimming in a lake or ocean, the bugs, plants, and water creatures that you are exposed to can cause irritating skin conditions that can interfere with your lifestyle. While some of these skin conditions are minor, others can cause more severe problems that can take months to heal. While board-certified dermatologists can diagnose and treat these types of skin reactions, it’s usually much easier to avoid them by taking proper precautions.

“Exposure to certain bugs, plants, and water creatures can adversely affect your otherwise enjoyable leisure activities or necessary household or work activities,” said board-certified dermatologist Julian Trevino, MD, FAAD, chair, department of dermatology, Boonshoft School of Medicine, Wright State University in Dayton, Ohio. “When you know more about how your environment can affect your skin, you can more effectively plan your outdoor and household activities to protect your skin.”

Some of the most well-known hazardous plants are poison ivy, poison oak and poison sumac. When you are exposed to these plants, you may develop an allergic reaction to the oily resin in the leaves and stems, which can cause an itchy rash. In some cases, you may also develop swelling and blisters. Often, the rash appears in a straight line due to how the plant brushes against your skin. If you are exposed to these plants, you should immediately rinse your skin with lukewarm water and avoid using soap as it could spread the plant’s oil. In addition, wash your clothing as well as everything that may have plant oil on its surface, including pets and gardening tools. To relieve the itch, Dr. Trevino recommends taking short, warm baths, applying a damp, cool washcloth to the affected area, applying calamine lotion, and taking an over-the-counter antihistamine. If this doesn’t help, or if you’re having a severe reaction, see your dermatologist.  

Other common plant-related skin problems can be caused by the spines and thorns of plants, such as cacti, figs, mulberries, and thistles. If you are cut or scratched by these spines or thorns, you may experience a skin reaction ranging from mild skin discoloration to small or large blisters. These plants can also cause uncomfortable itchy skin. Scratching can damage the skin and increase the risk for an infection. Spines, thorns, and wood splinters also can cause minor swelling when lodged in the skin.

Some plants, like the stinging nettle, possess sharp hairs on the leaves and stems which release a chemical into the skin that can cause hives and a burning sensation. Other plants, like hogweed and citrus fruits, contain chemicals that can cause discoloration on sun-exposed skin, which can last for months or even years. Dr. Trevino recommends avoiding stinging nettle and hogweed when possible, wearing protective clothing, and promptly washing exposed skin when gardening or handling them. Dr. Trevino suggests rinsing the skin and reapplying sunscreen after eating or drinking citrus while outside in the sun to avoid a skin reaction.

Plants aren’t the only living things that can cause skin problems. People can be exposed to water creatures in freshwater, saltwater, and home aquariums that can cause a skin reaction.

When participating in recreational water activities like snorkeling and scuba diving, swimmers should watch out for coral, which are a common source of injury. If you touch or scrape your skin against coral, it can cause a rash, stinging and burning, and hives. Dr. Trevino recommends rinsing any cuts or scrapes from coral with cold water and consulting a doctor about a tetanus shot. If the area becomes infected or coral fragments get stuck in the skin, see a physician for treatment.

In waters across the world, jellyfish stings are a common, painful injury. The severity of the sting depends on the type of jellyfish. The pacific box jellyfish is one of nature’s most dangerous creatures and is found in Australia’s Great Barrier Reef. A related species of box jellyfish can be found on the tropical Atlantic coasts of South American, Mexico and the United States.

“Jellyfish stings can cause itching, swelling, burning, hives, and discoloration of the skin,” said Dr. Trevino. “Delayed reactions such as abdominal pain, headache and nausea also have been reported.”

If you are stung by a jellyfish, Dr. Trevino says that you should immediately get out of the water and rinse the affected skin with sea water. You can use vinegar to neutralize the venomous part of the jellyfish that is stuck in the skin and use a tweezer or scotch tape to remove the tentacles and stinging cells.

Walking barefoot in the ocean can cause injuries if you step on a sea animal, such as stingrays and sea urchins. Stingrays have a sharp, venomous tail and sea urchins have painful, protruding spines. Since they live in the bottom of the water, fisherman and swimmers may be injured if they inadvertently step on them. Reactions can include nausea, fatigue, discoloration at the site, swelling or itching skin. If you experience respiratory distress, you should seek immediate medical attention.

Even at home, your skin can be exposed to harmful bacteria in aquariums. If you have a fish tank, be careful when cleaning it if you have injured skin as this can result in an infection which can cause a skin tumor or ulcer and require medical treatment.

To protect yourself against skin conditions and infections from aquatic creatures, Dr. Trevino says to avoid touching marine animals, including beached creatures; wear a wetsuit while surfing, diving, and snorkeling; wear gloves when collecting shells; avoid areas with shallow coral reefs; and walk with a shuffle in shallow waters where stingrays may be encountered. When cleaning your fish tank, it is recommended to avoid direct contact with aquarium occupants and wear thick gloves.

Sea creatures aren’t the only kind of living creature that can cause a skin reaction. Bugs can cause a wide variety of skin conditions, which range from a minor annoyance, such as itchy, discolored bumps or hives, to dangerous, life-threatening reactions. A person’s reaction depends on a variety of factors, including the type of bug, how the injury occurred and the person’s health.

The most common bugs that people encounter are arthropods including:

• Bees/wasps/ants (which can cause a painful reaction where stung or bitten)
• Beetles 
• Caterpillars/moths/butterflies (which can have a painful sting) 
• Centipedes (which can cause painful stings) 
• Millipedes (which can cause skin burns and discoloration) 
• Mites 
• Mosquitoes/flies (which are known to carry the West Nile, Chikungunya and Zika viruses)
• Scorpions 
• Spiders (including black widow and brown recluse spiders)
• Ticks (which can cause Lyme disease and a red meat allergy) 

“The best treatment for bug bites and stings is prevention,” said Dr. Trevino. “If you experience a bite or sting by an insect, treat the symptoms with over-the-counter antihistamines or see your dermatologist. Severe reactions may require emergency treatment with epinephrine or the administration of antivenom. If you develop a skin rash that doesn’t go away, see a board-certified dermatologist.”

Dr. Trevino recommends the following tips to avoid bug bites and stings:

• Use insect repellent. To protect against mosquitoes, ticks and other bugs, use insect repellent that contains 20 to 30 percent DEET on exposed skin and clothing. Always follow the instructions on the repellent and reapply as directed. If you are also wearing sunscreen, apply your sunscreen first, let it dry, and then apply the insect repellent. Do not use sunscreen that contains insect repellent, as sunscreen must be applied liberally and often while insect repellent should be applied sparingly.
• Take measures to reduce tick-borne diseases such as mowing the lawn regularly and removing debris and leaves.
• Wear appropriate clothing. If you know you’re going to be out at night or hiking in a densely wooded area, dress appropriately to prevent bug bites. Cover exposed skin as much as possible by wearing long-sleeved shirts, pants, socks and closed shoes instead of sandals. For additional protection, pull your socks up over your pants and tuck your shirt into your pants. You can also pre-treat outer layers of clothing with insect repellent containing the active ingredient permethrin. Follow the directions carefully and allow the clothes to dry for at least two hours before wearing them.
• Use bed nets. If sleeping in the great outdoors, use bed nets to protect against mosquitoes. Look for one that has been pre-treated with pyrethroid insecticide. If it doesn’t reach the floor, tuck it under the mattress for maximum protection.
• Pay attention to outbreaks. Check the CDC Travel Health Notices website and heed travel warnings and recommendations.

If you have a pet, they can also expose you to plants and bugs that can cause skin reactions and diseases. They can transport ticks or brush up against poison ivy. It’s important to check your pets when they come in from outdoors, especially after hikes and walks, and if you think they may have been exposed to harmful plants, rinse them thoroughly with water.

When traveling to unknown areas, it’s important to research the area in advance to find out if there are any hazards from bugs, plants or water creatures. Contact city or county parks districts, nature centers or an entity that is similar to get this information.

“Board-certified dermatologists know the skin reactions that can be caused by bugs, plants and aquatic organisms and they can diagnose and treat reactions,” said Dr. Trevino. “If you have questions about a reaction caused by a plant, bug or water creature, contact your dermatologist or healthcare professional.”

To find a board-certified dermatologist in your area, visit aad.org/findaderm.