Papular urticaria, also known as infantile urticaria and urticaria-like moss, is an allergic skin disease common in childhood and more frequent in spring and autumn. Most current opinion is that the onset of papular urticaria is related to insect bites and can be said to be an exogenous allergic reaction caused by arthropod bites. When patients are bitten by arthropods, such as bedbugs, fleas, mosquitoes and concealed insects, the saliva of the insects can be injected into the human skin. The disease can be caused in children with a tendency to allergic qualities. Most believe that is a delayed allergic reaction, the general sensitization process takes 10 d. After repeated bites, desensitization, so the disease children since the age of 7 years, with increasing age, the prevalence gradually decreased, middle-aged people basically do not have this disease. In addition, some scholars suggest that a small number of patients may be allergic to certain foods, especially proteins. Clinical manifestations: Papular urticaria often develops in late spring, summer and early autumn during the warm season, mainly in children and adolescents over the age of 1 year, especially in preschoolers. The disease tends to occur on the trunk and extremities, and the head and face are less commonly affected. The lesions appear as pemphigoid papules or pemphigoid blisters. The typical lesion has a fusiform shape with a small central papule or blister. Tension blisters may also appear on the distal extremities and palmar topography. The rash may be clustered or scattered, but is generally asymmetric. Children have severe itching, especially at night. The rash is often followed by purulent skin diseases such as impetigo due to scratching, but there are usually no systemic symptoms and the local superficial lymph nodes are not enlarged. The duration of the disease is about 1 to 2 weeks, and after the damage subsides, temporary pigmentation spots may remain, which are prone to recurrence. Treatment: 1. Local treatment is mainly symptomatic treatment According to the performance of the lesions, you can choose a lotion or emulsion with antipruritic and anti-inflammatory effects for external application, such as 1% thin lotion, 1% mint cream, corticosteroid ointment, etc.. If there is secondary infection, it is appropriate to control the infection first. 2, systemic medication antihistamines can be used as a routine application, generally used both antihistamine effect, but also sedative effect of drugs, such as benadryl, fenagan, chlorpheniramine, cycloheximide, etc.. Oral calcium lactate or calcium gluconate tablets have some efficacy. It is often used in combination with antihistamines. The combination of vitamin C or vitamin B12 with antihistamines can also give better results. Prevention: Since the cause of papular urticaria is mainly insect bites, the key to prevention is to improve environmental, indoor and personal hygiene to eliminate the breeding of insects that cause the disease. Insecticides can be sprayed in and around the house to eliminate bedbugs, fleas, mosquitoes and other harmful arthropods.