It takes about 1 week for a person with scarlet fever to get well from a rash, but this also depends on whether or not treatment is given and the severity of the illness. If no treatment is given, it is likely to be about 1 week. If the patient with scarlet fever is particularly ill and does not undergo any treatment, it is likely to take more than 1 week to about 2 weeks to get well, and in some cases, it may even lead to complications, resulting in some critical conditions for the child, when the duration of the illness will be longer. In scarlet, if early diagnosis is made and sensitive antibiotics are applied, the rash will recede in about 24 hours after the application of antibiotics, so early diagnosis and timely application of antibiotics are more important, and then the rash may only last for 1-2 days, or even 3-4 days, and will not last for too long.