Protein allergy and botulinum toxin: is there a risk?

The short answer: botulinum toxin is a protein, and the formulation may contain other components (excipients). So in a patient with a significant protein allergy or a previous reaction to toxin, the way forward is to read the package insert of the product you use, check the excipients and assess the history before injecting. A true allergic reaction to the toxin itself is rare, but when it happens, it can be severe. The decision is the professional's, after the medical history.

This page helps you organize the investigation and the conversation when the patient arrives saying "I'm allergic to milk, egg or some medication, can I have botox?".

What is botulinum toxin made of?

Type A botulinum toxin, used in HOF, is a purified protein. Products differ in protein complex, stabilizers and excipients. Some contain, for example, human albumin or other biologically derived components; others have different additives. The differences between products are covered in differences between type A botulinum toxins.

For your decision, what matters is what appears on the package insert and label of the lot you will use, not a general rule. It is not this page's role to say which product has which component.

Which allergies deserve attention?

When taking the medical history, ask about:

• protein allergy (milk, egg, other foods) with a significant reaction, such as anaphylaxis;
• previous reaction to botulinum toxin, of any brand;
• allergy to components listed in the product's package insert;
• neuromuscular disease, which is another contraindication to toxin, not an allergic one;
• use of medications that interact with the toxin's effect.

A mild food allergy, with no history of a severe reaction, is usually assessed calmly by reading the insert. A severe allergy, on the other hand, calls for more care and, in many cases, an allergist's opinion. The relationship with other injectable products is covered in severe allergy and filler.

How to run the consultation

If there is a history of anaphylaxis to any component, the prudent recommendation is not to inject without specialist assessment. The emergency protocol is in anaphylaxis in the HOF office and the emergency kit should always be available.

Allergic reaction to the toxin: what does it look like?

Hypersensitivity reactions to the toxin exist, but are rare. They can appear as itching, hives, swelling and, in severe cases, shortness of breath and a drop in blood pressure. They usually appear from minutes to hours after injection.

Do not confuse it with other, more common effects, such as pain at the injection point, a small bruise and headache, described in botox: side effects, nor with anxiety and the vasovagal reaction, which cause pallor and dizziness but have a different cause.

What if the patient has had it before and reacted?

The first step is to characterize it. Ask what they felt, when, for how long, whether they needed medication and which product was used. Telling an allergic reaction apart from an expected effect or another cause avoids contraindicating needlessly and avoids re-exposing someone who should not be.

• Expected or local effect (pain, small bruise, headache): not an allergy.
• Suspected allergy: stop, record, refer for assessment.
• Insufficient response to the product: a different matter, covered in botulinum toxin treatment failure.

In significant reactions, assess whether to report according to adverse event reporting (in Brazil, to Anvisa).

Record and obtain consent

Record in the patient record the type of allergy, the package insert consulted, the product lot and the approach. The informed consent should mention the risk of allergic reaction. There is a template in informed consent for botulinum toxin. On lot traceability, see traceability of injectables.

Where does Harmy fit in?

Harmy does not assess allergies or recommend products. The decision to inject or not is clinical and comes before anything else. If the plan goes ahead, the projection helps show the planned change in the marked areas, as an illustrative simulation, without replacing the assessment.