Hand, foot and mouth disease usually appears on the hands, feet, around the mouth and lips, etc. In some children, the rash is more frequent on the elbows and knees. If the rash is generalized, there may be a combination of other viral infections, such as chickenpox, rubella, measles and so on. 1. Chickenpox: the rash mainly appears in the chest, abdomen, back, limbs less, the rash is centripetal distribution, appear in batches, the rash is characterized by red macules, herpes, scabs, often combined with the emergence of fever. 2. Rubella: caused by rubella virus infection, with a short prodromal period, low-grade fever and rash, and swollen lymph nodes behind the ear and occipital area. 3. Measles: in addition to the rash, often accompanied by fever, inflammation of the upper respiratory tract, conjunctivitis, the rash is characterized by a red maculopapular rash, measles mucous membrane spots on the mucous membrane of the mouth and cheeks, and after the retreat of the rash will be left with pigmentation and other characteristics. Hand, foot and mouth disease appears generalized rash, it is recommended to go to the pediatric internal medicine or dermatology to further clarify the diagnosis, symptomatic treatment.