Allergic and hypersensitivity reactions (non-anaphylactic)

Reference material only. This article is general reference information, not clinical, medical or legal advice. It does not replace your clinic's own written emergency protocols, your clinical judgement, up-to-date professional guidance, or the emergency services. In an emergency, call 999 without delay. Every clinic remains responsible for its own emergency preparedness, training, equipment and drugs, and for acting within each practitioner's scope of competence and insurance.

Not every allergic reaction is anaphylaxis. Many are mild to moderate and localised, but they must always be watched carefully, because a reaction can escalate. If at any point Airway, Breathing or Circulation are involved, treat as anaphylaxis and call 999.

What these look like

• Localised reactions: redness, itch, warmth or swelling at the treated site.
• Urticaria (hives): raised, itchy weals that may spread.
• Angio-oedema: deeper swelling, often of lips or eyelids, without airway compromise.
• Delayed hypersensitivity: reactions appearing hours to days later, sometimes as delayed-onset nodules with fillers.

Managing them

• Stop the treatment and assess A, B and C first to rule out anaphylaxis.
• For mild, localised reactions, cool compresses and reassurance are often enough.
• Oral antihistamines are commonly used for itch and urticaria, within your protocol and the patient's medicines.
• Delayed inflammatory reactions to filler may need review by the treating prescriber and management per current guidance such as ACE Group World.

Safety-netting

Keep the patient in clinic long enough to be confident the reaction is settling, not building. Give clear written advice on what to watch for and when to seek urgent help, and ensure they can reach the clinic. Warn specifically that any throat tightness, difficulty breathing or feeling faint means calling 999 at once.

Prevention

A thorough allergy and medical history before every treatment is your best defence. Record any known allergy prominently as a patient alert, and reconsider any agent linked to a previous reaction.