Antonyms for the term "scarlet rash" could include words like clear, smooth, and pristine. These words evoke a sense of cleanliness, health, and purity, which are the opposite of the red, swollen, and often uncomfortable rash associated with scarlet fever. Other antonyms that come to mind might be words like cool, calm, and soothing, which suggest relief from the discomfort and irritation of a rash. In general, antonyms for "scarlet rash" are likely to focus on the absence or relief of symptoms, rather than on any specific alternative condition or state.