Allergic Transfusion ReactionMANAGEMENT

SYSTEMIC AND MISCELLANEOUS PRESENTATIONS · 12 SECTIONS

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560 items

☷ Legend

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

Allergic Transfusion Reaction Anaphylaxis Angioedema Benedikt's Syndrome Cannabis-induced hyperemesis Eczema (acute flare)Gradenigo's Syndrome Horner's Syndrome (Acute)Huntington's Disease (Acute Presentation)Kanavel's Signs Lemierre's Syndrome Procedural sedation Radiation exposure Retained products of conception Sever's Disease Urticaria Venous air embolism

01Approach to the Critical Patient/attcp58

Immediate priorities

›First reflex at symptom onset

›Stop the transfusion immediately

›Clamp the line at the first sign of reaction

›Do not flush the existing tubing into the patient

›Maintain IV access with normal saline

›New tubing to keep vein open

›Avoid running residual product

›If progression beyond isolated skin findings, treat as anaphylaxis

›Bronchospasm, stridor, or hypotension trigger

›Class I recommendation for immediate epinephrine

›Airway and breathing threats

›Angioedema and laryngeal edema

›Tongue or lip swelling

›Stridor or voice change

›Bronchospasm

›Wheeze and chest tightness

›SpO2 < 90% as failure marker

›If airway compromise, early definitive airway control

›Prepare for difficult airway from edema

›Anesthesia or critical care to bedside

›Circulation threats

›Distributive shock from anaphylaxis

›SBP < 90 mmHg

›MAP < 65 mmHg

›Tachycardia and poor perfusion

›Weak pulses

›Delayed capillary refill

02History/hx62

Presentation pattern

›Core cutaneous syndrome

›Pruritus

›Generalized itching

›Onset during transfusion

›Urticaria and hives

›Wheals on trunk and limbs

›Present in about 70% of reactions

›Flushing and localized angioedema

›Facial flushing

›Periorbital or lip swelling

›Systemic and severe features

›Respiratory symptoms

›Dyspnea and wheezing

›Throat tightness or swelling

›Cardiovascular and GI symptoms

›Lightheadedness and palpitations

›Abdominal cramping with nausea

Key historical elements

›Temporal relationship

›Time from transfusion start to symptoms

›Within minutes suggests anaphylaxis

›Within 4 hours fits allergic reaction

›Volume of product infused before onset

›Small volume in severe reactions

›Note rate at time of reaction

›Blood product type

›Platelet transfusion as highest risk

03Physical Exam/exam45

Vital signs

›Stability snapshot

›Temperature

›Fever typically absent in allergic reaction

›Fever should prompt FNHTR or hemolytic workup

›Blood pressure

›SBP < 90 mmHg as anaphylaxis marker

›MAP < 65 mmHg as shock marker

›Heart rate and oxygen saturation

›Tachycardia in anaphylaxis

›Desaturation with bronchospasm

Focused exam

›Skin findings

›Urticarial wheals

›Trunk and extremity distribution

›Confluent in severe cases

›Angioedema

›Lips, eyelids, and tongue

›Maculopapular rash variant

›Airway and respiratory exam

›Upper airway

›Stridor and oropharyngeal edema

›Tongue or lip swelling

›Lung exam

›Wheezing and decreased air entry

›Bilateral crackles suggest TACO or TRALI not allergy

›Cardiovascular and abdominal exam

›Perfusion

04Differential Diagnosis/ddx49

Other transfusion reactions

›Febrile nonhemolytic transfusion reaction

›Fever >= 1 C rise with chills

›No urticaria

›Most common transfusion reaction

›ICD-10 R50.84 association

›Cytokine mediated

›Antipyretics for symptom control

›Acute hemolytic transfusion reaction

›Fever with flank or back pain

›Dark urine and hypotension

›DIC and sense of impending doom

›Positive direct antiglobulin test

›Hemoglobinemia and hemoglobinuria

›ABO incompatibility emergency

›Transfusion-related acute lung injury

›Acute respiratory distress within 6 hours

›Bilateral pulmonary infiltrates

›Hypoxemia without circulatory overload

›No urticaria or pruritus

›Donor antileukocyte antibodies

›Supportive ventilation

›Transfusion-associated circulatory overload

›Dyspnea and orthopnea

›Pulmonary edema and hypertension

›Elevated BNP

›Volume-related mechanism

›Diuresis responsive

05Laboratory Tests/lt31

Routine transfusion reaction workup

›Clerical and compatibility check

›Repeat type and crossmatch

›Verify ABO compatibility

›Confirm correct unit and patient

›Direct antiglobulin test

›Negative in allergic reactions

›Positive suggests hemolytic reaction

›Hemolysis screen

›Visual inspection of plasma and urine

›Pink or red plasma suggests hemolysis

›Dark urine suggests hemoglobinuria

›Free hemoglobin

›Plasma and urine free hemoglobin

›Negative in allergic reactions

›CBC with peripheral smear

›Baseline hemoglobin

›Schistocytes suggest hemolysis

Targeted labs for severe reactions

›Serum tryptase

›Draw within 1 to 3 hours of onset

›Elevation supports mast cell degranulation

›Best window 15 minutes to 3 hours

›Supports anaphylaxis diagnosis

›No confirmatory test for mild reactions

›Interpret with baseline tryptase

›Immunologic deficiency workup

›IgA level and anti-IgA antibodies

06Diagnostic Tests/dt59

Scoring Systems

›Severity grading of transfusion reactions

›Mild grade

›Isolated cutaneous symptoms

›Urticaria, pruritus, flushing

›Moderate grade

›Generalized urticaria

›Mild bronchospasm responsive to treatment

›Severe grade

›Anaphylaxis with hypotension

›Laryngeal edema or cardiovascular collapse

›Anaphylaxis clinical criteria

›Acute skin or mucosal involvement plus respiratory or hypotension

›Rapid onset over minutes

›Two or more organ systems

›Hypotension after known allergen exposure

›SBP < 90 mmHg

›Drop > 30% from baseline

›Limitations

›No validated transfusion-specific score

›Clinical trajectory supersedes grading

›Severity may evolve quickly

MRI

›MRI role

›Not indicated acutely

›No role in mild reactions

›Time and availability constraints

›Rare problem-solving use

07Disposition/dispo35

Level of care selection

›Discharge candidates

›Mild cutaneous reaction resolved with antihistamine

›Stable vitals for >= 30 minutes

›No respiratory symptoms

›Reliable patient and follow-up

›Educated on future precautions

›Documentation of reaction provided

›Observation and admission

›Moderate reactions with systemic features

›Observe minimum 4 to 6 hours

›Any respiratory symptom even if resolved

›Recurrent reactions in same episode

›Extended monitoring

›Reassess for alternative reaction

›ICU indications

›Anaphylaxis requiring epinephrine

›Hemodynamic instability

›Airway compromise

›Biphasic anaphylaxis concern

›Observe 6 to 12 hours minimum

›Continuous monitoring

Consultation and follow-up

›Specialist triggers

›Anaphylaxis to allergy and transfusion medicine

›IgA workup

›Future product planning

›Recurrent reactions to transfusion medicine

08Treatment/t75

Immediate management for all reactions

›First actions

›Stop or pause the transfusion

›Pause for mild cutaneous reactions

›Stop permanently if beyond skin

›Maintain IV access with normal saline

›New tubing

›Keep vein open

›Assess ABCs and vital signs

›Continuous monitoring

›Reassess frequently

Mild allergic reaction

›Antihistamine therapy

›Diphenhydramine

›25 to 50 mg IV or PO

›Grade 1A recommendation

›Monitoring response

›Observe for symptom resolution

›Watch for progression

›Restart decision

›If symptoms resolve completely

›Restart same unit at slower rate

›Direct observation

›If symptoms recur or progress

›Discontinue permanently

›Treat as escalating reaction

Anaphylaxis

›First-line epinephrine

09Special Populations/sp39

Pregnancy

›Pregnancy considerations

›Epinephrine remains first-line for anaphylaxis

›Maternal hypoxia harms fetus

›Do not withhold for pregnancy

›Antihistamine selection

›Diphenhydramine acceptable

›Avoid unnecessary sedation

›Maternal and fetal monitoring

›Maintain SpO2 >= 95%

›Fetal monitoring when viable gestation

›Positioning

›Left lateral tilt to improve venous return

›Avoid supine hypotension

Geriatric

›Older adult features

›Higher cumulative transfusion exposure

›Chronic anemia and malignancy

›Repeated sensitization

›Cardiovascular caution with epinephrine

›Monitor for ischemia and arrhythmia

›Still indicated for true anaphylaxis

›Comorbidity overlap

›TACO risk higher with cardiac disease

›Distinguish dyspnea cause carefully

›Anticholinergic sensitivity

›Antihistamine-related delirium risk

›Lower dosing consideration

10Background/b55

Epidemiology

›Incidence and burden

›Among most common transfusion reactions

›Platelet incidence about 302 per 100,000 units

›Highest risk product

›Severe anaphylaxis rate

›About 8 per 100,000 units

›Life-threatening potential

›Presentation distribution

›About 70% present with urticaria

›Most reactions mild and cutaneous

›High-risk populations

›Chronic transfusion recipients

›Sickle cell disease and thalassemia

›MDS and hematologic malignancy

›Prior allergic reaction

›Strongest predictor of recurrence

›Risk rises with each reaction

Pathophysiology

›Immune mechanism

›Type I hypersensitivity

›Histamine release from mast cells and basophils

›IgE-mediated in many cases

›Recipient antibodies to donor proteins

›Anti-IgA in IgA-deficient patients

›Anti-haptoglobin in haptoglobin deficiency

›Contributing factors

›Plasma allergen load

11Patient Discharge Instructions/pdi31

copy discharge instructions

›Allergic transfusion reaction home care

›Take antihistamines as prescribed

›Diphenhydramine may cause drowsiness

›Avoid driving if drowsy

›Rest and stay hydrated

›Resume normal activity as tolerated

›Skin itching may persist briefly

›Warning signs to return to ER

›Trouble breathing or wheezing

›Throat tightness or swelling

›Blue lips or face

›Dizziness or fainting

›Spreading hives

›Chest pain

›Fever or chills

›Dark urine

›Flank or back pain

›Future transfusion safety

›Carry documentation of this reaction

›Reaction type and severity

›Share with future providers

›Tell every provider before transfusion

›Premedication may be needed

›Washed products may be needed

›Follow-up

›Allergy and immunology after severe reaction

›IgA and anti-IgA testing in 2 to 4 weeks

12References/r21

Guidelines and key sources

›Guideline and review sources

›Delaney et al transfusion reactions review

›Lancet 2016

›Prevention, diagnosis, and treatment

›Hirayama allergic transfusion reaction review

›British Journal of Haematology 2013

›Pathogenesis and prevention

›Cochrane premedication review

›Marti-Carvajal et al 2010

›Allergic and febrile reaction prevention

›Evidence summaries

›Ning et al premedication meta-analysis

›Transfusion 2019

›No benefit in unselected patients

›Wappler-Guzzetta et al severe reaction prevention

›American Journal of Clinical Pathology 2025

›History-guided prevention

›Coding standards

›ICD-10 T80.61 anaphylactic reaction due to transfusion

›T80.62 other serum reaction due to transfusion

›SNOMED CT allergic transfusion reaction concept

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Reviewed by SymptomDx Medical Team · Last reviewed August 18, 2026

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