Professional pediatric hematology: structured clinical reasoning, concise science, safer handoffs.
High-yield frameworks for initial assessment, diagnostic direction, counseling, referral, and handoff. Designed for primary care, emergency care, hospital medicine, trainees, and shared-care teams. This is an educational reference, not an order set or substitute for local protocols.
Clinical methodology
Designed around hematology reasoning.
The professional desk follows a repeatable logic: verify the abnormality, phenotype the presentation, rule out time-critical disease, then narrow the differential with targeted diagnostics.
- Validate the signalRepeat or confirm unexpected results when clinically safe; review specimen quality, age-specific ranges, and medication/transfusion context.
- Classify the phenotypeAnemia by MCV/retic, bleeding by pattern, neutropenia by ANC/duration, and thrombocytopenia by isolated vs multilineage disease.
- Identify danger patternsFever in high-risk hosts, neurologic symptoms, critical-site bleeding, MAHA/TMA, acute chest syndrome, severe symptomatic anemia.
- Escalate with a clean handoffCommunicate vitals, exam, trend, smear, hemolysis/coagulation/renal data, treatment given, and the precise consultation question.
Interpretation guardrails
Approach by presentation
Start with the clinical pattern.
CBC pattern recognition plus clinical severity determines urgency. Repeat abnormal labs when stable, but do not delay emergency treatment for high-risk presentations.
Anemia
Microcytic, normocytic, macrocytic; reticulocyte response; hemolysis; transfusion and referral cues.
Bleeding / bruising
Platelet vs coagulation vs vascular/connective tissue patterns; VWD, hemophilia, rare disorders.
Thrombocytopenia
ITP versus marrow, immune, TMA, infection, medication, inherited platelet disorders.
Neutropenia
ANC severity, fever risk, chronicity, syndromic clues, immune or congenital etiologies.
Sickle cell urgent care
Fever, pain, acute chest syndrome, stroke, splenic sequestration, aplastic crisis.
MAHA / TMA
TTP, HUS, complement-mediated HUS, DIC, malignant hypertension, autoimmune/infectious mimics.
Anemia pathway
Initial pediatric anemia framework.
First questions
- Severity and symptoms: tachycardia, syncope, dyspnea, chest pain, heart failure signs.
- MCV category: microcytic, normocytic, macrocytic.
- Reticulocyte response: underproduction versus blood loss/hemolysis.
- Hemolysis markers: bilirubin, LDH, haptoglobin, DAT, smear.
- History: diet/milk, pica, menses, GI symptoms, jaundice, dark urine, infection, medications, ancestry, family history.
High-risk features
- Hemodynamic instability or severe symptomatic anemia.
- Associated neutropenia/thrombocytopenia, blasts, bone pain, hepatosplenomegaly, lymphadenopathy.
- Hemolysis with renal injury, neurologic symptoms, or thrombocytopenia.
- Failure to respond to appropriate iron therapy or atypical microcytosis.
Microcytic anemia quick contrast
| Feature | Iron deficiency | Thalassemia trait | Inflammation/other |
|---|---|---|---|
| RDW | Often high | Often normal/slightly high | Variable |
| RBC count | Often low/normal | Often relatively high | Variable |
| Ferritin | Low unless inflammatory confounding | Normal unless coexisting ID | Normal/high |
| Next tests | Iron panel, diet/loss evaluation | Hemoglobin electrophoresis/HPLC; alpha testing if needed | CRP/ESR, chronic disease evaluation, lead, GI/celiac as indicated |
Bleeding workup
Separate mucocutaneous from deep-tissue bleeding.
Bleeding history often outperforms screening labs. Normal PT/aPTT does not exclude VWD, platelet function disorders, factor XIII deficiency, or mild factor deficiencies.
Mucocutaneous pattern
Petechiae, bruising, epistaxis, gum bleeding, menorrhagia, bleeding after dental extraction.
- Consider thrombocytopenia, platelet function disorder, VWD, connective tissue causes.
- Initial labs: CBC/smear, ferritin if chronic bleeding, PT/INR, aPTT, fibrinogen, VWF antigen/activity, factor VIII.
Deep-tissue pattern
Joint bleeds, muscle hematomas, delayed surgical bleeding, intracranial or retroperitoneal bleeding.
- Consider hemophilia A/B, factor XI, factor XIII, fibrinogen disorders, acquired inhibitors, trauma/non-accidental injury where relevant.
- Initial labs plus factor assays guided by PT/aPTT and phenotype.
Screening pattern reminders
| PT | aPTT | Platelets | Possible direction |
|---|---|---|---|
| Normal | Prolonged | Normal | Hemophilia A/B, factor XI, XII, inhibitor, heparin contamination |
| Prolonged | Normal | Normal | Factor VII, vitamin K/liver/warfarin effect |
| Prolonged | Prolonged | Variable | Common pathway factors, fibrinogen, DIC, liver disease, vitamin K deficiency, anticoagulants |
| Normal | Normal | Low or abnormal function | ITP, inherited thrombocytopenia, platelet function disorder, VWD may still be possible |
Platelet pathway
Thrombocytopenia: ITP until it is not.
Supports typical ITP
- Isolated thrombocytopenia.
- Well-appearing child with bruising/petechiae.
- Normal hemoglobin for bleeding status and normal WBC differential.
- Smear without blasts or schistocytes.
Consider alternate diagnosis
- Anemia not explained by bleeding, neutropenia, blasts, dysplasia, schistocytes.
- Bone pain, fever, weight loss, night sweats, organomegaly, lymphadenopathy.
- Very young infant, family history, syndromic features, giant/small platelets.
Management lens
- Bleeding severity and context guide treatment more than platelet count alone.
- Avoid platelet-affecting medications unless specifically directed.
- Critical bleeding requires urgent hematology and institutional protocol.
Neutropenia pathway
Interpret ANC by context, severity, and duration.
Workup framework
- Confirm with repeat CBC/differential and smear when appropriate.
- Determine acute versus chronic and isolated versus multilineage cytopenias.
- Review infections, medications, autoimmune symptoms, growth, oral ulcers, gingivitis, skin infections, diarrhea, family history, ancestry.
- Consider nutritional, immune, viral, autoimmune, marrow failure, cyclic, and congenital etiologies.
Escalate urgently
- Fever with severe neutropenia or immunocompromised state.
- Toxic appearance, hypotension, respiratory distress, cellulitis, perirectal pain, mucositis, central line infection.
- Other cytopenias, blasts, organomegaly, or concerning constitutional symptoms.
Sickle cell urgent care
Complications to identify early.
Fever in sickle cell disease warrants prompt sepsis evaluation and empiric antibiotics per local pathway. Assess immunization status, splenic function, prior resistant organisms, central line, and clinical appearance.
Consider with chest pain, cough, fever, hypoxia, tachypnea, or new infiltrate. Manage with oxygen/respiratory support, antibiotics, analgesia, incentive spirometry when age-appropriate, transfusion consideration, and hematology involvement.
Focal deficits, severe headache, seizure, altered mental status, or aphasia are emergencies. Coordinate immediate hematology, neurology, imaging, and transfusion strategy per institutional protocol.
Assess reticulocytes and spleen size; consider splenic sequestration, aplastic crisis/parvovirus, hemolysis, blood loss, or delayed hemolytic transfusion reaction.
MAHA / TMA pathway
TTP and HUS are time-sensitive.
Thrombocytopenia plus schistocytic hemolysis should trigger rapid evaluation for thrombotic microangiopathy and early specialist involvement.
Immediate red flags
- Neurologic symptoms: confusion, seizure, focal deficits, severe headache.
- Oliguria/anuria, rising creatinine, severe hypertension, pulmonary edema.
- Severe hemolysis, marked thrombocytopenia, chest pain, or shock.
- Do not wait for the full historical “pentad” of TTP.
Initial evaluation
- CBC with smear, reticulocyte count, LDH, bilirubin, haptoglobin, CMP/creatinine, urinalysis, coagulation studies.
- DAT when immune hemolysis is possible; pregnancy test in adolescents where relevant.
- ADAMTS13 activity/inhibitor before plasma therapy if feasible without delay.
- Stool Shiga toxin/PCR/culture for diarrheal HUS; complement evaluation when atypical/complement-mediated HUS is possible.
Differential direction
| Clue | TTP | STEC-HUS | Complement-mediated HUS |
|---|---|---|---|
| Dominant organ signal | Neurologic may predominate; renal variable | Renal injury after diarrheal illness | Renal injury; recurrent/family history possible |
| Key test | Severe ADAMTS13 deficiency supports diagnosis | Stool Shiga toxin/PCR/culture | Complement testing/genetics; diagnosis can be clinical |
| Initial action | Urgent hematology/transfusion medicine; do not delay therapy | Supportive nephrology care; manage complications | Urgent nephrology/hematology; consider complement blockade per protocol |
Risk stratification
Danger patterns that should change tempo.
Use local emergency pathways, but these patterns should generally move the clinician from routine evaluation to urgent assessment or specialist-directed management.
| Pattern | Scientific concern | Do not miss | Typical immediate data to gather |
|---|---|---|---|
| High acuity Fever + SCD/severe neutropenia | Functional asplenia or impaired neutrophil defense | Sepsis, acute chest syndrome, central line infection | Vitals, cultures per protocol, CBC/retic, focused source evaluation, early antibiotics per pathway |
| High acuity Thrombocytopenia + MAHA | Microvascular thrombosis and organ ischemia | TTP, HUS, complement-mediated TMA, DIC | Smear, LDH, bilirubin, haptoglobin, creatinine/UA, PT/aPTT/fibrinogen, ADAMTS13/Shiga toxin/complement as indicated |
| High acuity Bleeding + head trauma/neurologic symptoms | Critical-site hemorrhage | Intracranial hemorrhage in hemophilia, VWD, ITP, rare disorders | Diagnosis/treatment plan, factor/VWF/platelet context, neuro exam, imaging coordinated with hemostatic therapy |
| Intermediate Persistent cytopenia or multilineage abnormality | Marrow production failure/infiltration or systemic disease | Leukemia, marrow failure syndrome, immune dysregulation, inherited cytopenia | Repeat CBC/diff, smear, retic, exam for organomegaly/lymph nodes, medication/infection/family history |
| Intermediate Microcytosis not fitting iron deficiency | Inherited globin synthesis disorder or mixed etiologies | Thalassemia trait/intermedia, lead, chronic inflammation, malabsorption | Iron panel with inflammation context, RBC count/RDW, hemoglobin analysis, family/ancestry history |
Referral triggers
When pediatric hematology should be involved.
Same day / emergency
- Suspected TTP/HUS/TMA.
- Sickle cell fever, stroke symptoms, acute chest, splenic sequestration, severe uncontrolled pain.
- Critical-site bleeding, hemophilia trauma, severe thrombocytopenia with mucosal/major bleeding.
- Febrile severe neutropenia or toxic appearance.
Urgent outpatient
- Severe or symptomatic anemia not requiring immediate stabilization.
- Persistent or unexplained cytopenia, multilineage abnormalities, abnormal smear.
- New suspected hemophilia/VWD with significant bleeding or upcoming procedure.
- Suspected thalassemia major/intermedia or transfusion need.
Routine / planned
- Microcytosis not responding to iron or possible thalassemia trait counseling.
- Chronic mild neutropenia without severe infection but persistent concerns.
- Family history of bleeding disorder or hemoglobinopathy.
- Preoperative bleeding risk assessment when history is positive.
Handoff template
Make referrals faster and safer.
Pediatric hematology handoff
Patient: age/sex, weight if relevant, diagnosis or concern.
Reason for call: anemia / bleeding / thrombocytopenia / neutropenia / sickle complication / TMA / other.
Current status: vitals, appearance, bleeding/infection/respiratory/neuro/renal symptoms.
Key labs: CBC with differential, retic, smear findings, PT/aPTT/fibrinogen, hemolysis labs, creatinine/UA, iron or hemoglobin studies as relevant.
History: onset, medications, family history, prior episodes, newborn screen, transfusions, central line, procedures, menstrual/GI history.
Actions taken: cultures, antibiotics, imaging, fluids, transfusions/products, analgesia, isolation, specialist calls.
Question: diagnostic guidance, transfer, urgent treatment recommendation, outpatient follow-up, procedure plan.