A personal care device, such as an irrigator, which may be an oral irrigator, a nasal irrigator, or similar. The personal care device may be used to cleanse a user's oral cavity, such as by injecting a liquid such as water into the spaces between a user's teeth. The device may include two housings that are slidably coupled together, with the upper housing containing the electronic components and the lower housing containing a reservoir for holding water or other liquids that are to be dispensed. During use, the lower housing may slide upwardly as the liquid is dispensed due to the formation of a vacuum inside of the cavity of the lower housing. Thus, an air flow passageway may be formed that extends from the ambient into the cavity of the lower housing. The device may also include a cap with a locking closure to prevent accidental opening and spilling.