19.2 Anemia, Lead, Sickle Cell Trait & Bleeding Clues

Hematology and oncology clues are clinical category #19 on the CPNP-PC outline. Domain II wants microcytic anemia named, lead confirmed, and bleeding sorted by how sick the child looks. Domain III wants iron replaced, cow’s milk turned down, sickle cell fever sent to the ED, and no aspirin. You are not running a leukemia service. You are deciding whose low hemoglobin is diet, whose is trait, and whose petechiae do not go home.

Quick Answer: Screen hemoglobin at 12 months (Bright Futures). Toddler iron deficiency: excess cow’s milk. Microcytic split: iron (high RDW, lower RBC count) versus thalassemia trait (normal RDW, higher RBC count). Lead: venous confirm, CDC blood lead reference value 3.5 µg/dL, environmental action, chelation via specialty at high levels. Sickle disease: newborn screen, penicillin, fever = emergency, hydroxyurea via heme. Trait: counseling. Well child, isolated low platelets after a virus: ITP. Ill child, HSM, blasts, bone pain: leukemia. Do not give aspirin.

Clinic opening. A 14-month-old drinks 32 ounces of cow’s milk daily, looks pale, and has a hemoglobin of 8.9 g/dL with MCV 62 fL. If you label “thalassemia” without indices or a dietary history, or if you hand the family aspirin for teething pain, you missed this section.

Iron deficiency versus thalassemia trait

Iron deficiency is the common nutritional anemia of late infancy and toddlerhood. Risk: prematurity, delayed iron-containing complementary foods, cow’s milk before 12 months, and excessive cow’s milk after 12 months (often >16–24 oz/day) that displaces iron-rich food and can irritate the gut. Restricted diets and menstrual blood loss in adolescents join the list. Bright Futures includes hemoglobin (or hematocrit) at 12 months as universal disease screening — a safety net, not a substitute for the milk history. Risk-based screening continues afterward (preterm, dietary risk, poverty, special needs).

Labs of iron deficiency: microcytic, hypochromic anemia, high RDW (new small cells mixed with older ones), low reticulocyte count until treatment, low ferritin, high TIBC/transferrin. Mentzer index (MCV/RBC) >13 leans iron deficiency; <13 leans thalassemia trait — a teaching aid, not a gold standard.

Thalassemia trait (α or β) is also microcytic. The child is often well, the diet is fine, the RBC count is normal or high, RDW is normal, and ferritin is not low. A family from a high-prevalence ancestry or a newborn screen “hemoglobin Bart’s” or “Hb E” comment is a clue, not a requirement. Do not treat trait with years of iron. Do not miss iron deficiency because you assumed ethnicity explained everything — both can coexist.

Treat confirmed iron deficiency with oral elemental iron (commonly 3–6 mg/kg/day of elemental iron, divided, on a relatively empty stomach if tolerated) and dietary change. Recheck hemoglobin in about 4 weeks for a rise; that rise is part of the diagnosis. Continue several months to refill stores. Counsel dark stools, keep iron out of reach (toddler overdose is an emergency), and stop the milk flood. Severe anemia with instability, hemoglobin so low the child is in heart failure, or failure to respond is hematology, not another month of hope.

Lead: confirm, environment, specialty chelation

Lead is a neurotoxin with no known beneficial role. Screening ages and Medicaid EPSDT (commonly 12 and 24 months) live with other disease screens; this section is the hematologic and environmental response. A capillary fingerstick is a screen. False elevation from skin contamination is common. Confirm with a venous blood lead level before you upend a household or refer for chelation.

Follow current CDC action — do not recite a retired “level of concern” of 10 µg/dL as if it were still the reference. As of recent CDC guidance, the blood lead reference value is 3.5 µg/dL. That value identifies children with higher exposure than most U.S. children so you act: repeat venous testing on the CDC/health-department schedule, take an environmental history (housing year, peeling paint, renovation, imported spices/cosmetics/toys, occupational take-home dust, water), involve local public health for investigation when indicated, optimize iron and calcium nutrition (deficient children absorb more lead), and follow until levels fall. Chapter 20 covers broader toxicology; here you own the venous number and the “this is not zero-risk because it is under 10” counseling.

Chelation is not primary care. Children with high confirmed venous levels (CDC teaching still centers chelation decisions around levels in the mid-40s µg/dL and above, plus encephalopathy at any high level) go to a pediatric environmental health or toxicology/hematology pathway — often a hospital. You do not start dimercaprol from a sample closet. You do not chelate a capillary 4 µg/dL.

Clinic vignette. A 2-year-old in pre-1950 housing has a capillary lead of 7 µg/dL. You obtain a venous confirmation, report per local rules, start environmental and nutrition counseling, and schedule follow-up. You do not wait for 10. You do not chelate in clinic.

Sickle cell disease versus trait

Sickle cell disease is on the newborn screen. Confirmatory hemoglobin electrophoresis/HPLC is arranged early. Primary-care jobs until hematology fully owns disease-modifying therapy:

• Penicillin prophylaxis from early infancy (typically twice-daily penicillin starting by about 2 months) until at least 5 years in HbSS/HbSβ⁰ — longer if the hematologist says so. This is infection prevention, not optional.
• Immunizations, including pneumococcal conjugate and polysaccharide on the high-risk schedule, meningococcal, and annual influenza.
• Fever is an emergency. A child with sickle cell disease and fever (commonly taught as ≥38.3–38.5°C) needs same-day emergency evaluation, blood culture, and parenteral antibiotics covering pneumococcus and other encapsulated organisms — not acetaminophen and a morning phone call. Chest pain, hypoxia, severe pallor, splenic enlargement, neurologic change, and priapism are also emergencies (acute chest, aplastic crisis, splenic sequestration, stroke).
• Hydroxyurea is disease-modifying and is directed by pediatric hematology, not started from a primary-care antibiotic template. You support adherence and monitor the specialty plan.
• Pain plans, hydration, and when to use the ED belong in writing for the family.

Sickle cell trait is usually asymptomatic. Counseling: generally compatible with a full life; rare hematuria or exertional rhabdomyolysis/collapse under extreme heat, dehydration, or high-intensity effort; genetic counseling for future partners (if both have trait, each pregnancy has a 25% chance of disease). Do not put trait children on penicillin prophylaxis or hydroxyurea. Do not tell them they have “a little sickle cell disease.”

ITP versus leukemia — and when to refer

Immune thrombocytopenia (ITP) classically follows a viral illness by days to weeks. The child is well-appearing, afebrile now, with petechiae, purpura, or epistaxis and an isolated thrombocytopenia. Hemoglobin and white count are otherwise reassuring; smear has large platelets and no blasts; there is no hepatosplenomegaly, no hard nodes, no bone pain. Primary care refers hematology; observation versus IVIG/anti-D/steroids is a specialty decision. Do not start systemic steroids in clinic before leukemia is off the table. Do not give aspirin or ibuprofen for the accompanying viral aches — platelet function matters when the count is already low. Acetaminophen is the usual office analgesic message. Activity restriction while platelets are very low is counseling, not a playground lecture.

Leukemia (ALL is the pediatric prototype) declares as more than petechiae: pallor, fever, bone or joint pain (night pain, limp), fatigue, hepatosplenomegaly, lymphadenopathy, mediastinal compression (cough, orthopnea, SVC plethora), and more than one cytopenia. Blasts on smear end the argument. That child is same-day hematology/oncology or ED, not a trial of ITP observation.

Refer heme/onc now when you see:

• Petechiae or purpura in a sick-appearing child
• More than one cytopenia, or cytopenia plus blasts
• Hepatosplenomegaly with bleeding or pallor
• Lymphadenopathy that is hard, fixed, matted, supraclavicular, or growing through antibiotics
• Mediastinal symptoms (orthopnea, facial swelling, persistent cough with adenopathy)
• Unexplained bone pain, night pain, or limp with systemic signs
• Anemia that does not match diet or does not respond to iron

Do not give aspirin in these children — not for fever, not for “thin the blood,” not as Kawasaki leftovers from the sample closet. Aspirin increases bleeding risk in thrombocytopenia and is not a primary-care hematology therapy. (Reye-syndrome teaching still applies to febrile viral illness as well.)

Clinic vignette. A 4-year-old is playful with scattered petechiae two weeks after a cold, CBC shows platelets 12,000/µL, normal hemoglobin and WBC, no HSM. That can be ITP — call hematology, no aspirin, no empiric steroid from the drawer. A 4-year-old with petechiae who is pale, febrile, refusing to walk, and has a spleen tip is leukemia until the hospital says otherwise.

Exam traps

1. Calling every microcytic anemia thalassemia — or iron — without RDW, RBC count, ferritin, and diet.
2. Skipping the 12-month hemoglobin.
3. Treating a capillary lead as confirmed, or waiting for 10 µg/dL as if that were still the CDC reference value.
4. Chelating in primary care.
5. Sending sickle cell fever home.
6. Managing trait as disease, or disease as “just trait.”
7. Starting steroids or aspirin for presumed ITP.
8. Sending home petechiae plus sick appearance, HSM, or two cytopenias.

Clinic close. Milk and a high RDW: iron, then recheck. High RBC, normal RDW, fine diet: think trait, not endless iron. Venous lead, 3.5 µg/dL is the current CDC reference value, environment first, chelation by specialists. Newborn screen FS: penicillin, fever emergency, hydroxyurea via heme. Newborn screen FAS: counseling. Well isolated thrombocytopenia: ITP pathway. Sick, bones, spleen, blasts: oncology today. No aspirin.