Scarlet Fever - Diagnosis

Diagnosis of scarlet fever also depends on eliminating other possible diseases with similar symptoms. For example, measles (see measles entry) has many of the same symptoms as scarlet fever. However, a scarlet fever rash looks quite different from a measles rash. Also, scarlet fever is usually accompanied by a sore throat, and measles is not.

Some symptoms of strep throat (see strep throat entry), such as a sore throat and fever, are also similar to those of scarlet fever. But the two diseases are easily distinguished from each other by the appearance of the sandpaper-like rash that is associated with scarlet fever.

A doctor looks for the characteristic rash as well as the "strawberry tongue" (which only appears in children). If questions remain, laboratory tests can be used to make a final determination. Blood tests, for example, can distinguish between a bacterial infection (like scarlet fever) and a viral infection (like strep throat). A throat culture can also be used to do this.

A throat culture consists of a small amount of material taken from the patient's throat. with a cotton swab. The material is then allowed to grow in a warm place overnight before the culture is examined to determine whether the infection is caused by bacteria or a virus.