Thousands in Hanoi get skin blisters as rove beetles enter mating season

Han, a 7-year-old girl, suffered numerous spots of skin rashes and inflammation spots. Her family took her to the National Hospital of Dermatology and Venereology, where doctors determined they were caused by contact with paederus fuscipes, or rove beetles.

Since the patient scratched her skin, the rash spread, they added.

Another patient, Thanh, 19, had skin rashes in his groin due to rove beetles. He had had rashes caused by the beetles in the past, and so this time decided to self-medicate by using his old topical medication, and this only made things worse.

He was treated later at the dermatology hospital.

Ngoc of Ha Dong District said she woke up one morning feeling her cheek burning, and found a red rash similar to shingles when she checked in the mirror.

Since it was close to her eyes, she decided to go to the hospital, where she was diagnosed with dermatitis linearis or skin inflammation caused by contact with rove beetles.

In the last three months the dermatology hospital has treated around 900 patients with contact dermatitis, with cases of dermatitis linearis accounting for half.

Paederus fuscipes are a group of insects that belong to the order Coleoptera and genus Paederus. They do not bite or sting, but release fluid that contains pederin, a blistering chemical. Their pederin is more potent than cobra venom.

Paederus fuscipes members. Photo by CDC

Doctors said since it is the insects’ mating season, their numbers are increasing. They are attracted by lights in homes and fly in and land on objects like clothes and beds. When a person comes in contact with a rove beetle, it releases a fluid that causes skin irritation and blisters.

The skin and allergy center at the 108 Military Hospital has also received numerous patients with dermatitis linearis.

Dr Nguyen Thi Quynh Trang of the center said the first signs are an itchy, burning feeling on the skin. The skin then turns red and become inflamed with blisters of 1-5 mm size.

Dr Nguyen Thi Thanh Thuy of the National Hospital of Dermatology and Venereology warned that scratching could cause the lesions to spread.

Besides, the rashes are sometimes misdiagnosed as shingles or herpes. In severe cases, patients also experience low-grade fevers and pain in the neck and armpits.

The lesions typically heal after a week, but leave behind dark patches that take time to fade.

One of the common mistakes is that patients do not go to hospitals to get the rashes treated and instead opt for self-medication.

Doctors suggest that people should avoid opening windows and turn off lights where possible if they live in areas with the beetles.