That all depends on how quick you caught them. I know of people that had to treat themselves more than once because they did not know they had more than fleas.Once the treatment is given and all linens and such have been cleaned, the rashes and bite marks should heal very quickly if the treatment was effective. Good Luck....my husband brought them home to us when he had to sleep in a trailer while he worked of town for a few weeks, they itched something fierce, but I did exactly as the dr told me and the day after the treatment, our scabs started healing immediately, we caught them quickly though...it is just not normal to ever itch that bad