Doctors Warn Against Improper Treatment of Insect Bites as Cases Rise

As summer arrives, various insects enter their active period, and insect bite dermatitis also ushers in its peak season.

Recently, reporters learned from the dermatology departments of several Shanghai hospitals that the number of outpatient visits for insect bite dermatitis has increased by nearly 30% compared to last month, with a notable number of cases where the condition worsened due to incorrect treatment. Meanwhile, the topic of "AI identification of insect bites" has gained significant traction on social media, with many people uploading photos of their rashes for AI to "diagnose."

Doctors remind everyone that instead of agonizing over which insect bit them, it is more important to avoid incorrect treatment and promptly identify warning signs.

Improper treatment after a bite is truly dangerous

"Insect bite dermatitis, commonly known as papular urticaria, is a skin allergic reaction caused by insect bites or injection of venom from insects such as mosquitoes, midges, bedbugs, and fleas," said Gu Chaoying, a dermatologist at the Department of Dermatology, Huashan Hospital Affiliated to Fudan University. "Insect bite dermatitis itself is not scary; what is truly dangerous is improper treatment after being bitten."

Last weekend, 7-year-old Pipi was brought into the consultation room of Fan Qing, director of the Department of Dermatology and Venereology at Fengxian District Central Hospital, by his father. The child's left instep was painful and itchy, swollen like a "small bun," making it impossible to wear socks or shoes. Upon inquiry, it was learned that Pipi had been bitten by a mosquito while playing in a park near his home. Because of the itching, the child couldn't help but scratch. The parents thought, "Scratching is fine," but the child's itching worsened, and he not only scratched his skin open but also developed a high swelling near the mosquito bite.

"After being bitten by insects, the body will have a local allergic reaction, which causes itching," Fan Qing explained. "Scratching, a mechanical stimulus, causes mast cells to release more histamine, which is why we 'itch more the more we scratch.'"

Although scratching can temporarily relieve itching, it can also cause skin damage. The tissue fluid and serum that ooze out then become a breeding ground for bacteria. Fan Qing mentioned that since June, the clinic has seen more than a dozen cases of insect bite dermatitis daily, and nearly one-third of them developed secondary infections due to scratching. Elderly people and children, with their weaker skin barrier function, are particularly susceptible. Children are prone to secondary infections like impetigo, while the elderly may develop more severe consequences such as soft tissue infections and cellulitis.

Besides scratching, the misuse of anti-itch products can also cause secondary damage. Fan Qing reminds people that many are accustomed to using products like "Fengyoujing" (a type of medicated oil), "Qingcao Gao" (green grass ointment), and mosquito repellent lotion for itching. However, during summer, human skin is in a hot and humid state for extended periods. The absorption of stimulating ingredients like menthol and camphor in these products increases significantly, potentially triggering secondary allergies, i.e., contact dermatitis.

"AI insect identification" is not accurate and blind trust increases anxiety

"Nowadays, more and more popular science articles list the skin manifestations of various insect bites. Many people self-diagnose based on these articles after being bitten. Some even upload photos of the affected area to AI, trying to determine which insect is responsible. In reality, the accuracy rate is not high," Fan Qing noted. "I have encountered patients in the clinic who come for consultation with AI-generated results. Someone with a common insect bite dermatitis was told by AI it was a skin tumor; another person sent a photo of a rash after being bitten by fleas, and AI said it was caused by a rare venomous insect, scaring him into coming to the hospital overnight."

"Skin disease diagnosis is not just about looking at photos," Fan Qing explained. Doctors not only observe the morphology of the skin lesions but also inquire about the patient's medical history, such as where they have recently been, how long the symptoms have appeared, and whether they have a fever, using these details as important clues for diagnosis. AI diagnosis is not only questionable in itself but also adds new anxiety.

However, Fan Qing also mentioned that some insect bites have obvious characteristics that the public can learn about in advance and take basic precautions before seeking medical attention. For example, a young woman recently discovered a "black mole" on her waist during a picnic, only to realize it was a blood-engorged tick. Having read popular science articles, she did not attempt to remove it herself but immediately went to the hospital for treatment.

"When bitten by a tick, never pull or slap it forcefully, otherwise the mouthparts will break off in the skin and may transmit serious diseases such as Lyme disease and fever with thrombocytopenia syndrome," Fan Qing said. The correct approach is to go to the hospital immediately for professional removal of the tick by a doctor and to observe closely for one month. If symptoms such as fever or rash appear, seek medical attention promptly.

"To minimize insect bites as much as possible, the most important thing is to 'stay away from the source of insects,'" Gu Chaoying advised. When traveling, try to avoid areas with dense vegetation or high humidity, such as bushes and fields. When going on outings or picnics, wear clothing that minimizes skin exposure and use mosquito repellent products scientifically. Most insect bite dermatitis can resolve on its own, so there is no need to be overly anxious. After being bitten, you can first wash the affected area with soapy water, apply a cold compress to relieve itching, and if necessary, apply a weak corticosteroid cream.

"In a situation where humans and insects coexist, it is impossible to completely avoid insect bites," Fan Qing said. The important thing is to know which situations do not require panic, which situations require timely treatment, and not to turn small problems into big troubles due to incorrect operations.

Author: Zhang Feiya

Source: Wenhui Bao