1, herpes pharyngitis is mainly caused by coxsackie group A virus infection clinical manifestations: rapid onset, high fever, sore throat, irritability, salivation, anorexia, vomiting, general discomfort, swallowing difficulties, depression and convulsions. If the disease occurs alone, there are often no systemic symptoms, and infants and young children often show crying and reluctance to eat. Rash characteristics: typical symptoms appear in the pharynx. The rash is characterized by congestion of the pharynx and within 2 days of onset, several small grayish-white herpes appear on the oral mucosa, surrounded by a red halo. 2 to 3 days later, the red halo increases and expands, and the herpes breaks down to form a yellow ulcer. This kind of mucosal rash is mostly seen in the anterior tonsillar column, but can also be located on the soft palate, the uvula, tonsils, but does not involve the gingiva and buccal mucosa. 2, hand, foot and mouth disease is mainly caused by enterovirus infection clinical manifestations: drowsiness, limb trembling, easy to startle, limb weakness, convulsions, and even coma in severe cases; headache, frequent vomiting; shortness of breath, mouth and lips cyanosis; cold limbs and flowers, blood pressure first high and then low. Rash characteristics: four sites – hands, feet, mouth, buttocks scattered spotted rash, maculopapular rash, small herpes; there are four characteristics – no pain, no itch, no crust, no scar. The rash appears on the day of fever or rash out before the fever. 3, measles is mainly caused by measles infection virus clinical manifestations: cough, conjunctival congestion, photophobia, khat symptoms, can be combined with pneumonia, laryngitis, encephalitis, myocarditis. Rash characteristics: maculopapular rash, pressure fading, from behind the ear – frontal face – neck – trunk – limbs – hands and feet, the skin between the rash is normal, oral mucosa koplik spot, 3 to 5 days after the rash is complete, after the rash receded there is pigmentation and fine flaking. The rash emerges in 3 to 5 days with fever, and the rash period is the peak of fever. 4, early childhood emergency rash is mainly caused by human herpes virus type 6, 7 infection clinical manifestations: mostly seen in infants and young children within 2 years of age, generally behind the ear appears swollen occipital lymph nodes, may be accompanied by febrile convulsions and mild diarrhea. Rash characteristics: red small dense maculopapular rash, head, face, neck and trunk are common, the extremities are less common, one day all together, the next day will begin to fade, the rash receded without hyperpigmentation and desquamation. The rash appears in 3 to 5 days after the fever subsides. 5. Scarlet fever is mainly caused by group A, type B hemolytic streptococcal infection. Clinical manifestations: tonsillar congestion and edema, headache, vomiting, enlarged and painful lymph nodes in the neck and submandibular area. Rash features: diffuse skin congestion, dense pinpoint-sized papules on the skin – chicken rash, with itching, with prune tongue, pale circle around the mouth, 4 to 5 days rash with the heat down and subside, appear large flakes of peeling skin. Fever 1 to 2 days out of the rash. 6, chickenpox is mainly caused by varicella-zoster virus infection clinical manifestations: infants and children with mild symptoms, older children can have headache, fatigue, sore throat, can be complicated by pneumonia, encephalitis, etc.. The rash is characterized by a maculopapular rash that develops into a papular-herpetic rash within a few hours, with papules, herpes and crusts visible at the same time. The rash is distributed centripetally, first on the trunk, scalp, and then on the face and extremities, but rarely on the distal extremities, with itching, and the scabs fall off in about 1 week. The rash appears within 1 day of fever or before the rash appears. 7, rubella is mainly caused by rubella virus infection clinical manifestations: systemic symptoms are relatively light, the child behind the ears, the occipital lymph nodes swollen and will be accompanied by tenderness. Parents should seek medical attention when they find the rash. The rash is characterized by a maculopapular rash that fades when pressed by hand. The rash appears on the face, neck, trunk, and extremities. The rash will not appear after the rash recedes. The rash will appear after 1 to 2 days of fever. 8, Kawasaki disease specific cause is unknown clinical manifestations: mainly cardiac complications, is the main cause of pediatric acquired heart disease, and is associated with the occurrence of sudden cardiac death in young adults. Rash features: conjunctival congestion, mouth and lips chapped, hands and feet fingers (toes) hard end, the whole body can be seen congestive rash or maculopapular rash, may have like “measles” or “scarlet fever”-like rash and grass plum tongue. During the recovery period, the body temperature drops and the rash disappears, with flaky peeling skin around the anus and buttocks. The rash appears in 2 to 3 days after the fever. 9, drug rash is mainly caused by some drugs clinical manifestations: symptoms of the original disease, a recent history of drug use, drug hypersensitivity syndrome occurs when the superficial lymph nodes swell. Rash characteristics: drug-induced rash is variable in form, such as maculopapular rash, herpes, scarlet fever-like rash, pockmarked rash, etc.; the skin has a pronounced itchy feeling, friction and pressure areas more. The rash may appear before, during or after the onset of fever.