Recognising a complication after injectable treatment

Complications after injectable treatment are uncommon, and the serious ones are rare. They are also time critical, which means the useful knowledge is not statistical, it is practical: what is normal, what is not, and what you do about it at eleven o'clock on a Saturday night.

This is information to have before treatment rather than after it. The single most important thing to obtain at your consultation is a phone number that is answered out of hours by somebody who can act.

What is normal

Expect some or all of the following, and expect them to improve rather than worsen day by day.

• Swelling. Usual for the first 24 to 72 hours, more pronounced in the lips than anywhere else, and often worse on waking.
• Bruising. Common, particularly around the eyes, the lips and between the brows. Typically visible for five to ten days and changing colour as it resolves.
• Tenderness and small firm areas. Common in the first week or two as product integrates and swelling settles.
• Small raised bumps after toxin. Settle within about twenty minutes.
• Mild headache after upper face toxin. Usually within the first day or two.
• Redness and pinprick marks. At injection points, resolving quickly.

The pattern that matters is direction of travel. Normal effects peak early and improve. Anything that starts later, gets worse, or is markedly asymmetric in a way it was not immediately afterwards deserves a phone call.

The emergency: vascular occlusion

The complication that drives every safety protocol in dermal filler practice is vascular occlusion, where product either blocks or compresses a blood vessel and the tissue it supplies is deprived of blood. It is rare. It is also an emergency, because tissue deprived of blood supply can be permanently damaged, and if the vessels involved connect to the eye, vision can be affected.

The warning signs, which may appear during the injection or over the following hours:

• Pain that is severe, increasing, or out of proportion to what you were told to expect.
• Skin that blanches white, or develops a dusky, mottled, blue or purple pattern, often with a lacy appearance.
• An area that feels cold compared with the surrounding skin.
• Any change in vision, including blurring, double vision, loss of part of the visual field, or pain behind the eye.
• Later, over days, blistering, crusting or breakdown of skin in the affected area.

The areas of highest concern are those where the vascular anatomy is unforgiving: the area between the eyebrows, the nose, the nasolabial region and the forehead. This is why many experienced practitioners approach those regions cautiously or avoid some of them entirely.

What to do, in order

1. Contact your practitioner immediately. Not by direct message. By phone, using the out of hours number you obtained at the consultation.
2. Say what you are seeing. Pain out of proportion, colour change, cold skin, vision change. Use those words. They are the ones that trigger the right response.
3. If it involves vision, treat it as an emergency. Seek urgent medical attention without waiting for a call back.
4. If you cannot reach your practitioner within minutes, go to an urgent care service or emergency department. Tell them what product was injected, when, and where. Take the product name with you if you have it.

For hyaluronic acid fillers there is an enzyme that dissolves the product, and its usefulness is time dependent. A clinic injecting hyaluronic acid should hold it on the premises and have a written protocol. Asking whether they do is a completely reasonable pre-treatment question, and the answer tells you how seriously the practice takes the risk. That question belongs alongside the others in what a good consultation looks like.

Infection

Infection after injectable treatment is uncommon but not rare, and it can appear early or late. Suggestive signs are increasing redness spreading outward, heat, swelling that worsens after day three, pus or discharge, and systemic symptoms such as fever or feeling generally unwell.

Cold sore reactivation is a specific issue around the mouth, and anyone with a history of them should mention it before lip treatment, since preventive antiviral treatment may be appropriate. Infection requires prompt medical assessment rather than watchful waiting, because in the presence of filler it can be more complicated to treat than an ordinary skin infection.

Delayed and late problems

Some issues appear weeks or months after treatment. Delayed inflammatory reactions can present as firm, tender swelling in a previously treated area, sometimes triggered by an illness, a vaccination or a dental procedure. Nodules can form and may be inflammatory or non-inflammatory, and the distinction changes the management. Product can also migrate from where it was placed, most visibly around the mouth.

None of these are emergencies in the way vascular occlusion is, but all of them need assessment rather than reassurance over a message. Return to the practitioner who treated you if you can. If that relationship has broken down, seek an appointment with an experienced practitioner or a dermatologist, and take your treatment records with you.

Problems specific to botulinum toxin

Toxin complications are generally functional rather than dangerous: eyebrow asymmetry, a heavy brow, a temporary droop of the upper eyelid, an uneven smile after lower face treatment, or difficulty with speech or drinking after treatment around the mouth. They are frustrating and they are temporary, resolving as the effect wears off over roughly three to four months.

Report them to your practitioner. Some can be partially improved by careful additional treatment, and all of them are useful information for planning the next round. Any difficulty with swallowing or breathing after treatment is a different matter entirely and needs urgent medical assessment.

Reporting, and where to go next

Suspected side effects of a medicine, and adverse incidents involving a medical device such as a dermal filler, can be reported by patients as well as professionals through the MHRA Yellow Card scheme. Reporting matters because device surveillance depends on it.

If your concern is about the conduct of a registered professional, the relevant statutory regulator has a concerns process. If the practitioner is on a voluntary register, that body also handles complaints about its members. Where the practitioner holds no registration at all, your route is the clinic's own complaints process, their insurer, and consumer law. This asymmetry is one of the strongest practical arguments for checking registration before booking, which is set out in verifying credentials.