What to Do About Rove Beetle Bites? Correct Treatment and Prevention Methods Explained

Every year, August to September is the breeding period of rove beetles and also the peak incidence period of rove beetle dermatitis. Many people are troubled by them, so what should be done after being bitten by a rove beetle? How to prevent it? What to do when encountering a rove beetle?

1. How to treat rove beetle bites

After being crawled on by a rove beetle, be sure to keep the affected area clean; it can generally heal on its own. However, to speed up healing, prevent skin infection, or reduce itching and pain, the patient should immediately seek medical attention in the dermatology department of an authoritative hospital. The doctor will generally prescribe topical medicine to apply to the affected area, and it will usually get better in about two weeks.

After human skin comes into contact with a small amount of the venom (such as when a rove beetle crawls across the skin), the skin will develop dot-like, patch-like, or cord-like erythema, after which the center becomes grayish-brown and necrotic. If the injured area is not large, there will be mild itching and pain; if the injured area is large (such as when multiple areas of skin have been crawled on by rove beetles), there will be strong itching and pain, possibly accompanied by swollen lymph nodes, fever, and so on.

If human skin comes into contact with a large amount of the venom (such as when the venom flows onto the skin), the injured area will produce blisters, and the surrounding skin will become red and swollen, with a ring-shaped area of original skin color between the blisters and the redness and swelling. The blisters can be broken, such as by squeezing them open with a cotton swab and then washing them clean with salt water, but blisters will soon reappear afterward. After the blisters naturally disappear before long, the affected area will bulge, with the center where the original blisters were sunken, like a crater, but a typical crater is round, while the affected area on the skin is linear. The skin tissue in the raised part of the affected area will all become necrotic, forming a dark coffee-colored scar, and new skin will grow under the scar, but the new skin will be very pale and somewhat different from the surrounding skin, causing the affected area after healing to look like it healed after being cut by a knife. Therefore, the resulting scars have the greatest impact on the skin.

2. How to prevent rove beetles

1. Clean up indoor and outdoor sanitation to prevent mosquitoes and insects from breeding, and at the same time close the screens properly

2. Turn off the lights and sleep at night, and check the bed for rove beetles before sleeping to avoid crushing them to death

3. Use various mosquito-repellent measures as much as possible, such as plugging in a mosquito killer or applying floral water

4. If a rove beetle stays on the skin, blow it away with your mouth, then wash the skin that touched the rove beetle with clean water

5. Generally, there are fewer rove beetles in cities, while there are more in the countryside and forests. When traveling away from home, pay special attention, try to wear long pants, and carry mosquito-repellent products such as floral water with you.

3. What should be done when encountering a rove beetle

Ms. Qian said that 3 days ago, after she got up in the morning, she felt her face was a little itchy. When she looked in the mirror, she saw that quite a few small red spots had appeared on her face, “looking like mosquito bites, but it hurt when I scratched them with my hand.” Ms. Qian had thought about just applying some anti-itch ointment, but the situation was not as she had imagined. “Later the red spots expanded somewhat and even began to ulcerate, so I hurried to the hospital to take a look.” Ms. Qian said that after arriving at the dermatology department of the hospital, she found four or five patients in the waiting room with the same symptoms as hers. In the end, after hospital examination, they learned that they had actually been bitten by poisonous rove beetles.

Ms. Qian recalled that 4 days earlier, after dinner in the evening, she had taken a walk in the grove in her residential community and had also rested her feet on the lawn. “The doctor also said that poisonous rove beetles are generally in the grass, so I must have been bitten at that time.”

1. Do not sit casually on lawns

Experts from the Chongqing Center for Disease Control and Prevention also remind the public that when going to the outskirts, do not sit casually on lawns, because in addition to poisonous rove beetles, there will also be infestations of poisonous caterpillars.

According to the introduction, poisonous rove beetles mainly live in grass near water in fields, and when temperatures are high they also fly indoors at night. The greatest harm of poisonous rove beetles is causing large-area dermatitis or skin rashes. People who are bitten develop large-area skin redness and swelling, or even ulceration and pus, on part or all of the body, with both itching and pain. If a poisonous rove beetle is found crawling on the body, absolutely do not slap or rub it with your hands; instead, gently blow it away or use another object to brush the insect off.

Like poisonous rove beetles, poisonous caterpillars can also cause dermatitis or skin rashes. Poisonous caterpillars mainly grow on trees such as mulberry, pine, and tea trees. The poisonous needles on the skin they shed drift with the wind and attach to the human body or clothing, which can cause dermatitis and urticaria. If going to the woods to play during a holiday, the public should wear long-sleeved clothes and pants, tightly fasten the trouser legs and cuffs, wear a hat, and wrap a towel around the neck.

2. Do not slap a rove beetle directly with your hands

“If you do not harm it, it will not harm you.” According to relevant experts, only a few species of rove beetles are “poisonous,” namely the subfamily Paederinae and a small number of other species. However, poisonous rove beetles do not “sting people.” The reason they cause human skin allergies and toxic reactions is that rove beetles contain “pederin” in their bodies. It is strongly acidic, exists in the bodies of rove beetles, and is part of their defense mechanism. Only when their bodies are damaged will this toxin overflow.

“When encountering a rove beetle, do not slap it directly with your hands.” Zeng Xiaopeng explained that although rove beetles have no venom glands outside their bodies and do not sting people, they contain venom inside their bodies, and after being slapped to death the venom will flow out. Once the toxin enters the body, it will cause an allergic reaction in the skin and produce cord-like or patch-like redness and swelling. Generally speaking, this symptom will disappear in about a week and will not leave aftereffects. Therefore, the Weibo statement that “if this insect is on your body, just gently blow it away with your mouth, and absolutely do not slap it with your hands” still has a certain scientific basis.

Mo Jianchu also stated that if an adult rove beetle is crushed so that its venom touches human skin, it will indeed cause redness and swelling of the human epidermis. In severe cases, when the epidermis is damaged, ulceration may occur. “But to say that rove beetles endanger life is incorrect. Only a very small number of people among those with allergic constitution may be in life danger due to severe allergy after encountering this insect. Generally speaking, this insect will not cause death.”

4. How to prevent harm from poisonous rove beetles

Zeng Xiaopeng said that compared with mosquito bites, the welts bitten by poisonous rove beetles can be described as “burning and painful.” If you accidentally come into contact with their body fluid, you can neutralize it with alkaline substances such as soapy water or soda water. After rinsing clean with clear water, you can apply calamine lotion. If it is severe, you should go to a regular hospital for treatment as soon as possible to avoid causing more serious skin infection.

On how to prevent harm from poisonous rove beetles, experts remind: close doors and windows properly when sleeping in summer. If there are screens, close them as tightly as possible; because the mesh of screens is coarse, rove beetles can enter the house through gaps in the screens, so the windows must be closed.

Be sure to turn off the lights when sleeping. Because rove beetles have a strong phototaxis, after they enter the room, turn on the lights as little as possible, or place a basin of salt water under the light to trap and kill them by making use of the rove beetle's phototaxis. In addition, check the bed for rove beetles before turning off the lights and sleeping.

Take various mosquito-repellent measures. At home, insecticides such as deltamethrin or fenvalerate can be kept on hand to spray and kill insects indoors and in the surrounding environment. When leaving home, insecticides can be sprayed indoors to kill rove beetles that have entered the house.

Carry wind-medicated oil with you. Rove beetles die immediately when they encounter wind-medicated oil; even if 2-3 drops of wind-medicated oil are added to 500ml of water, rove beetles will also die within one and a half minutes.

Keep the outdoors tidy. Promptly remove rotten wood, waste materials, and weeds around the house so that rove beetles have no breeding places or habitats.

“If residents go to the suburbs for outings, they should take necessary protection, try to wear long-sleeved clothes and pants; they can also spray some mosquito repellent to help prevent poisonous rove beetle bites.” Zeng Xiaopeng emphasized.

Every year, July and August are the active period of rove beetles. After the beginning of the dog days, the weather will become increasingly humid and stuffy, as if one is in a large steamer. This is also one of the hardest periods of summer and a period of high incidence of poisonous rove beetle injuries. Recently there has been more thunderstorm weather, and standing water after rain easily breeds mosquitoes and insects. Experts remind families with children to pay even more attention to preventing mosquito and insect bites. In addition to choosing products for preventing mosquito and insect bites, such as floral water and mosquito nets, also pay attention not to stay in grassy areas for long periods, especially do not sit on lawns after rain.

5. Treatment methods for rove beetle dermatitis

1. Systemic therapy

(1) For mild cases, take oral antihistamines, such as cyproheptadine 2mg each time, 3 times daily, for 3-5 consecutive days;

(2) For severe cases, glucocorticoid preparations should be added, such as prednisone 10mg, twice daily, for 3-5 consecutive days;

(3) If skin lesions are widespread or there is secondary infection, antibiotics should be added, such as erythromycin ethylsuccinate, 0.25 grams each time, 4 times daily, for 3 consecutive days.

2. Local therapy

(1) Wet compress: a 5% sodium bicarbonate solution or 1:8000 potassium permanganate solution can be used for wet compress, 15-30 minutes each time, 2-3 times daily;

(2) Nantong snake medicine tablets: grind into powder, mix with vinegar or cold boiled water into a paste for external use, 2-3 times daily;

(3) Chloramphenicol calamine lotion: for external use, 3-5 times daily.