The skin is an important defense organ of the human body because it is in direct contact with the external environment, so one of the most important functions of the skin is the barrier function, including the defense against mechanical damage, physical damage, chemical damage, microorganisms, etc. Normal skin surface hosts many microorganisms, and when the skin barrier function is abnormal, microorganisms may take advantage of the situation and cause diseases. Yellow sores are caused by bacterial infections secondary to abnormal skin barrier function. Xanthogranuloma, also known as impetigo, is a bacterial infectious skin disease that occurs in children. The main causative agent is Staphylococcus aureus. The disease can be transmitted by auto-inoculation or by contact. The disease is triggered by skin damage, poor hygiene, poor body resistance, high heat and humidity, heavy sweating, or skin maceration, which are conducive to bacterial proliferation. It can be divided into common impetigo and herpetic impetigo. Impetigo vulgaris: It occurs on the face, around the mouth and nose, limbs and other exposed areas. The initial rash is red bumps and papules, which rapidly turns into pustules, and the herpes dries up into thick honey-yellow crusts, which constantly expand in all directions and can fuse with each other. The rash is itchy and new rashes appear on other areas due to scratching. In severe cases, fever, lymphadenitis, and even sepsis occur. Herpetic impetigo: It occurs on exposed areas such as the face and extremities. It starts as a blister of corn to bean size, which rapidly turns into a large blister, and the blister fluid turns from clear to turbid, with pus accumulating at the bottom of the blister, showing the phenomenon of half-moon pus accumulation, which is one of the characteristics of this type of impetigo. The wall of the blister breaks down and forms a vesicular surface, and the pus dries and crusts over. Self-perceived itching, usually without systemic symptoms. Treatment: Topical antibiotic creams (such as fusidic acid cream, mupirocin cream, etc.) are applied topically, and herpes fluid extraction is feasible when the pustules are large; thicker crusts can be removed with sesame oil or soybean oil before topical antibacterial drugs are applied. Oral or static dose of sensitive antimicrobials, such as penicillin-resistant semi-synthetic penicillin, one or two generations of cephalosporins, etc., it is best to choose antibiotics based on the results of drug sensitivity tests. Prevention: Pay attention to skin cleanliness, maintain good skin hygiene, disinfect contaminated clothing, and remove triggering or aggravating factors in a timely manner.