Vancomycin allergy
Reaction to vancomycin, including \"red man\" flushing.
About vancomycin allergy
Vancomycin is a powerful antibiotic given by drip, and sometimes by mouth, for certain serious bacterial infections. It is well known for a reaction called vancomycin flushing reaction, previously termed red man syndrome, which is not a true allergy. It happens when the drug is infused too quickly, causing direct release of histamine that produces flushing, itching and a red rash over the upper body. Because it depends on the infusion rate rather than an immune memory, it can often be avoided by infusing more slowly. Genuine IgE-mediated allergy to vancomycin also exists but is less common.
The flushing reaction usually appears during or shortly after an infusion, with redness, itching and sometimes a drop in blood pressure, matching the rapid onset described. True allergic reactions can be more serious, including hives, swelling and, rarely, anaphylaxis with breathing difficulty and collapse. Vancomycin is also occasionally linked to delayed severe reactions such as DRESS, with rash, fever and organ effects.
Management is led by the medical team, who can slow the infusion and distinguish this predictable reaction from genuine allergy, which changes whether the drug can be used again. Record any reaction and tell every doctor, nurse and pharmacist. A severe reaction is a medical emergency call 999. Never take or adjust the medicine without professional advice.
Common triggers
- Vancomycin and products containing it
Symptoms
- Skin rash, hives or itching
- Swelling of the face, lips or throat
- Wheezing or difficulty breathing
- Dizziness or a drop in blood pressure
- In severe cases, anaphylaxis
Avoidance & management
- Tell every doctor, pharmacist and dentist about the allergy
- Wear a medical-alert bracelet if advised
- Check the ingredients of combination medicines
- Discuss safe alternatives with your prescriber
- Seek emergency care for a severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.