Effects, side effects, complications

4.2.1Expected effects

These are not complications and should be described to you in advance as part of what the treatment involves.

• Small raised areas at each injection point, usually settling within hours.
• Redness across the treated area.
• Tenderness to touch for a day or two.
• Mild swelling, more pronounced and longer lasting around the eyes.
• A sensation of tightness or fullness in the treated area.

If none of these was mentioned before treatment, the consent conversation was inadequate regardless of how the treatment turns out.

4.2.2Side effects

Bruising

Common, particularly in thin skinned areas and in people taking anticoagulants or antiplatelet medication. Follows the ordinary course of a bruise. Unpleasant rather than dangerous.

Prolonged swelling

Most associated with the periorbital area, where drainage is limited. Can persist beyond the expected few days. Not usually dangerous, frequently distressing, and with no reversal agent the management is time.

Small lumps and irregularity

Palpable or visible small lumps at or between injection points are reported. Many settle. Where they do not, the options are limited compared with hyaluronic acid, and this asymmetry belongs in the consent conversation.

Asymmetry

Faces are asymmetrical before treatment and remain so afterwards. Differences that were unnoticed can become noticeable once attention is directed at an area, which is a perceptual effect as much as a treatment effect.

4.2.3Complications

Infection

Introduction of organisms through the puncture sites. Presents as increasing pain, spreading redness with warmth, sometimes fever, sometimes discharge. Needs assessment and usually treatment. The NHS page on cellulitis describes the presentation. This is not something to wait out.

Persistent nodules

Lumps that do not settle. Causes can include product related tissue reaction, low grade infection including biofilm, or granulomatous reaction. Distinguishing them matters because the management differs, and it is a clinical assessment rather than something to be judged from a website.

Allergic and hypersensitivity reactions

Uncommon and worth taking seriously when they occur. Immediate widespread reaction, difficulty breathing, swelling of the lips, tongue or throat is a medical emergency and the NHS page on anaphylaxis describes what to do. Delayed hypersensitivity presenting as persistent swelling or induration is a different presentation requiring assessment.

Vascular occlusion

The serious complication of facial injectables generally, in which injected material enters or compresses a vessel and interrupts blood supply to the tissue it serves. Presents with pain that is severe or out of proportion, blanching, mottling or a dusky appearance of the skin, and in periorbital treatment potentially with visual symptoms. It is a medical emergency and it is time critical. The article on what to do if something goes wrong sets out the route.

4.2.4Why no rates appear in this article

Because none can be calculated. Calculating a rate requires a numerator and a denominator. There is no national register of cosmetic procedures performed in the United Kingdom, so there is no denominator. Adverse event reporting through the MHRA Yellow Card scheme is voluntary and, in a private sector with no obligation to report and a commercial disincentive to do so, incomplete.

The consequence is that both the reassuring figures quoted by clinics and the alarming figures quoted by critics are constructed rather than measured. This document publishes neither. What it publishes is the list of what can happen, so that you can recognise it, and the route to act on it.

4.2.5The polynucleotide specific point

Most of the above applies to any injectable treatment in the face. What is specific to this category is the absence of a reversal agent.

With hyaluronic acid, several of the problems above have a specific corrective route through hyaluronidase, including, critically, vascular occlusion. That does not make hyaluronic acid safe and this material dangerous. It means the response to a problem here relies on general measures, time and clinical management rather than on removing the material.

This is a real difference and it should be stated in a consultation. If it was not, that is a finding about the consultation.

4.2.6Reporting

If something goes wrong you can report it yourself, and you do not need your clinic's agreement. The MHRA Yellow Card scheme accepts reports about medical devices from members of the public. Reporting does not resolve your problem, and it is not a complaint mechanism. What it does is contribute to the surveillance data that currently barely exists, which is the reason nobody can tell you a rate.

Separately, if the practitioner is on a professional register, that regulator has a complaints route. If the practice is registered with a premises regulator, so does that regulator. The regulation chapter sets out who is who.

4.2.7What you should have been told

Before treatment: the expected effects, the recognised side effects, the complications including the serious one, what would be done about each, the absence of a reversal agent, and how to reach someone urgently including out of hours. In writing, so that you are not relying on memory.

Professional guidance on consent is explicit that risks material to the particular patient must be discussed in terms they can act on. A list of risks recited quickly while a form is signed does not meet that description, whatever the form says afterwards.