It is a small beetle with a body length of 0.6-0.8 cm, with a black head and orange thorax, and the sheath wings are usually covered in the front abdomen. It is diurnal and lives in damp grass, rotten wood, gutters, rocks and other dark places during the day, and comes out at night to feed, and is light-oriented. When it crawls on the human body at night, if it is beaten and rubbed by hand, the insect body is crushed and the strong acidic venom in the body of the cryptoptera flows out, causing an acute inflammatory reaction, i.e. “cryptoptera dermatitis”. This disease is mostly seen in summer and autumn, especially in hot weather after rain, and the skin damage is mainly erythema, papules, blisters, pustules, vesicles, etc.. In mild cases, the affected area has a burning pain and a slight itch, severe local pain and fever, headache, nausea, vomiting and other systemic symptoms. Prevention and treatment methods: ① Improve environmental hygiene, eliminate the breeding ground of cryptoptera. Install screen doors and windows to prevent the invasion of cryptoptera indoors. ②If the insects fall on the skin, do not pat them with your hands, but knock them to the ground and trample them to death with your feet. ③If the insect has touched the skin, it should be washed with soap and then coated with 10% – 20% ammonia in order to neutralize the acidic venom. If the lesion is red, swollen or erosion, apply 1:5000 potassium permanganate solution wet compress, to reduce the exudate and then apply zinc oxide oil. ④ Oral anti-allergy drugs.