Most anxious phone calls after a treatment are avoidable, and the fix is almost always something that happens before the patient leaves rather than after they ring.
The usual failure is telling people what to avoid without telling them what to expect. A patient who has been told not to lie down for four hours but not told they will probably have small raised bumps for twenty minutes will ring you about the bumps. Describe the normal course out loud, and describe it in the order they will experience it: immediately after, tonight, tomorrow, next week.
Be specific about bruising. Say it can happen, say where it usually shows, say roughly how long it lasts, and say that concealer is fine once the skin is intact. Vagueness here generates more calls than anything else, because a bruise the patient was not warned about feels like something going wrong.
Give them the timeline for the result as well. Toxin does not work immediately, and a patient who was not told that will conclude on day three that it has failed. Say when they should judge it, and book the review then rather than leaving it open.
Written aftercare should be short enough to read. A page of contraindications gets skimmed. Three or four sentences of what is normal, three or four of what is not, and a number to call gets read and kept.
That number matters more than the rest of the sheet. Patients who cannot reach you go to social media, or to another practitioner, or to an emergency department, and all three make everything harder. If you cannot answer personally out of hours, say so plainly and tell them what to do instead.
The critical distinction to teach them is between normal discomfort and the things that need an urgent call. Pain that is increasing rather than settling. Skin that looks white, mottled or dusky. Any change in vision. Say those out loud, not just on the sheet, and say that ringing about them at any hour is the right thing to do.
Whoever answers your phone needs the same briefing. A receptionist taking a message from someone describing blanching skin is a delay you cannot afford. That call gets put through immediately, wherever you are.
On review appointments, book them before the patient leaves rather than inviting them to get in touch. Attendance is much higher, and a review is where you catch small asymmetries while they are still easy to fix, and where you build the relationship that produces repeat work.
Resist the temptation to reassure by minimising. Telling someone their swelling is nothing when they are worried about it does not reduce their worry, it reduces their willingness to tell you about the next thing. Take it seriously, look at it properly, and then say what you think.