In short. The small set of findings after a muscle-relaxing injection that need same-day or emergency care, each stated with the action that belongs to it.
Key points
- None of these findings is graded by how much it bothers you.
- A drooping eyelid may be more visible than an eye that will not close and less serious than one that will, and a fever at an injection site may feel trivial and be the most time-sensitive item on the list.
- The finding decides the action.
Most of the questions that follow a botulinum toxin injection are about how the result looks. A smaller set is about how the body is behaving, and the findings in that group have one thing in common: the action is fixed and does not depend on judgement. This page collects them and attaches the action to each, because the difficulty is rarely deciding what to do once a finding is recognised. The difficulty is recognising it in the first place.
Emergency care, immediately
Difficulty swallowing, speaking or breathing, or widespread muscle weakness, belongs in emergency care. These are the signs that the effect has reached muscles beyond those treated. A rash with swelling of the lips or throat, or difficulty breathing soon after an injection, is a reaction of a different kind and is treated the same way. For any of these, contact your treating team if you can reach them at once, and if you cannot, go to the nearest emergency department. Do not wait for a reply and do not wait to see whether it settles.
Care the same day
A second group needs care the same day rather than an emergency response. An eyelid that has dropped and cannot be lifted, or double vision, is assessed the same day. So is an eye that cannot be closed, or a gritty dry eye that is not settling, because the surface of the eye is no longer protected. A weak smile, an uneven mouth, or difficulty drinking without spilling is in the same group. Fever with spreading redness, heat or pus at an injection site suggests infection and is treated promptly rather than watched.
The action is attached to the finding, not to how you feel
None of these findings is graded by how much it bothers you. A drooping eyelid may be more visible than an eye that will not close and less serious than one that will, and a fever at an injection site may feel trivial and be the most time-sensitive item on the list. The finding decides the action.
What is a review, and what is not
A review appointment is the right route for the questions that are about the result: an asymmetry, a brow you did not expect, a smile that has changed, a result you dislike. These are real concerns and they are assessed properly, but they are assessed at a defined point — at about two weeks, once the effect has settled, and again at about four weeks if anything is still obvious. A review is not the route for anything on this page.
Seek emergency care now if
- There is difficulty swallowing, speaking or breathing, or widespread muscle weakness.
- There is a rash, swelling of the lips or throat, or difficulty breathing soon after the injection.
- There is an eye that cannot be closed, a drooping eyelid that cannot be lifted, or double vision — seek care the same day.
The one thing this page asks of a reader is to act on the finding rather than on the explanation. Each of these symptoms has an innocent explanation available, and choosing it is the mistake the page exists to prevent.
Frequently asked questions
Which symptoms need emergency care?
Difficulty swallowing, speaking or breathing, or widespread muscle weakness, and a rash with swelling of the lips or throat or difficulty breathing soon after the injection. These are emergencies from the moment they are noticed, and they are not observed or waited out.
Which symptoms need same-day care rather than an emergency?
An eyelid that has dropped and cannot be lifted, double vision, an eye that cannot be closed, a gritty dry eye that is not settling, a weak smile or an uneven mouth with difficulty drinking, and fever with spreading redness, heat or pus at an injection site. These need care the same day.
Can I wait until my review appointment?
Not for any of these findings. A review appointment is the right route for a result you dislike, an asymmetry or a brow change, which are assessed at a defined point. The findings on this page are a different category and are not what a review is for.
Risks & Limitations
- Botulinum toxin has no dissolving agent. An unwanted effect is managed by time rather than reversed, and nothing shortens it.
- The effect arrives gradually over several days and is judged at about two weeks, not on the day of treatment.
- Eyelid droop, brow change, facial asymmetry and a changed smile are recognised consequences of treating these areas.
- The rare findings that suggest spread beyond the treated area are difficulty swallowing, speaking or breathing, and widespread muscle weakness.
- Repeated treatment at short intervals is the main recognised driver of a reduced response over time.
When to Seek Care
- Difficulty swallowing, speaking or breathing, or widespread muscle weakness — seek emergency care now.
- A rash, swelling of the lips or throat, or difficulty breathing soon after an injection — seek emergency care now.
- An eyelid that has dropped and cannot be lifted, double vision, or an eye that cannot be closed — seek care the same day.
- A weak smile or difficulty drinking without spilling, and fever with spreading redness, heat or pus at an injection site — seek care the same day.
References & Further Reading
- U.S. Food and Drug Administration (FDA) — approved botulinum toxin products and their labelled warnings
- European Medicines Agency (EMA) — botulinum toxin assessment reports and product information
- National Medical Products Administration (NMPA, China) — approved products and their indications
- American Academy of Dermatology (AAD) — injectable safety information for patients
- Chinese Medical Association Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.