There are many plants with sharp hairs or trichomes on their leaves and stems that, when rubbed, not only bring about mechanical irritation, but the release of an irritating chemical mixture in the stems and leaves, which includes histamine, acetylcholine, 5-hydroxytryptamine, etc., also brings about intense irritation, which is a self-defense response to herbivores. If people are inadvertently exposed to such plants, skin damage is likely to occur. Erythema, burning sensation, itching, stinging sensation and even wind masses can occur after exposure to irritating plants, and some symptoms have a chance to appear 3-5 minutes after exposure and can last for several hours, even 12 hours or longer. Urticaceae is the most common, there is a fire hemp tree, more distributed in Australia, there has been documented that exposure to fire hemp tree has led to the death of several horses and a case of human death. Diagnosis of the condition is sometimes difficult because the person exposed may not be aware of the specific characteristics of the plant to which he or she is exposed. Sometimes certain dermatology-specific tests are required to make the identification. The time required for these tests is sometimes long, and most contact irritations are benign, self-limiting and do not require treatment, so there may be no need for testing from the patient’s perspective. Of course, the above is limited to cases where local irritation occurs, and if systemic reactions such as headache, diarrhea, fever, etc., or even severe epidermal peeling occur, a hospital visit is required as soon as possible. Certain plants, such as cactus and rose, are predominantly mechanically irritating dermatitis after contact, and the degree of damage to the skin is generally inversely proportional to the size of the protrusions. In some places, “cactus dermatitis” is common. Cactus pickers or people who accidentally fall into cactus bushes can develop intense itching and papular lesions. Another easily overlooked comorbidity is infection, for example, tetanus, Staphylococcus aureus, Mycobacterium spp. and Mycobacterium ulcerans can infect the body through mechanical injury. There are many methods of removing hooked hairs, warm wax, glue, plasters, masks, and transparent tape can be used on the relevant areas to remove hooked hairs quickly.