a parent brings her kindergarten-aged child in for a check-up because the child has been complaining of pruritus, especially at night, and appears to have a rash on his wrist. after taking scrapings of the lesion and providing topical application of permethrin 5% as ordered, the nurse sends the child home with instructions for re-treatment in one week. at the two-week follow-up appointment, the child continues to complain of pruritus. which statement best explains this finding?