Management depends on the severity of the reaction.
Most reactions to IV iron are mild, self-limited CARPA-type (“Fishbane”) events that resolve quickly when the infusion is paused. The key principle is to stop the infusion, observe, and restart slowly once symptoms abate.
1. Mild (Fishbane-type) reaction
- Typical features: Flushing, warmth, chest or back pressure, anxiety, mild dyspnea.
- Action:
- Stop the infusion immediately.
- Reassure the patient; monitor vital signs.
- Symptoms usually resolve within 5–10 minutes.
- Restart at half the previous rate once asymptomatic; most patients tolerate resumption without recurrence.
- Do not premedicate with antihistamines or steroids—they provide no benefit and may confuse the picture.
2. Moderate or uncertain reaction
- Features: Persistent symptoms, mild hypotension, or diagnostic uncertainty (Fishbane vs anaphylaxis).
- Action:
- Stop the infusion.
- Give oxygen and IV fluids as needed.
- Observe closely.
- If symptoms progress or airway involvement appears, treat as anaphylaxis.
3. Severe reaction (true anaphylaxis)
- Features: Hypotension, wheeze, stridor, urticaria, angioedema, collapse.
- Action:
- Stop infusion immediately.
- Administer intramuscular epinephrine (0.3–0.5 mg of 1:1000 solution).
- Provide airway and hemodynamic support (oxygen, IV fluids).
- Add antihistamines and corticosteroids only after epinephrine.
- Document and refer for allergy evaluation before any future IV iron exposure.
Follow-up
- Document the event clearly (timing, symptoms, vital signs, management, outcome).
- Distinguish between Fishbane-type and true anaphylaxis to avoid unnecessary “iron allergy” labeling.
- Most patients who experience mild or moderate CARPA-type reactions can safely receive IV iron again with slower infusion rates.
In summary: Pause, observe, and restart slowly for mild reactions; treat promptly with epinephrine for true anaphylaxis. Most IV iron reactions are mild, non-allergic, and do not preclude future use.