Geographic Tongue

A 7-year-old boy is brought to the pediatric clinic by his mother who noticed irregular red patches on his tongue that seem to change shape every few days. On examination, the tongue shows red atrophic areas with white serpentine borders. The child is otherwise asymptomatic and systemically well. The feature marked **C** in the diagram (migratory pattern of lesions) is the key distinguishing characteristic. Which of the following is the most appropriate management for this child?