Hematology

Question 1

What is the most common cause of acute kidney disease in children?

What is the etiology?

Answer 1

Hemolytic Uremic Syndrome (HUS)

E. Coli (Shigela like toxin)

Question 2

What is the hemolytic uremic syndrome triad?

What else can be seen in the presentation of HUS?

Answer 2

• Thrombocytopenia
• Schitzocytes (microangiopathic uremia)
• Progressive kidney insufficiency

Lethargy, seizures, abdominal pain, bloody diarrhea, vomitting

Question 3

What is the treatment for hemolytic uremic syndrome (HUS)?

Answer 3

• Mainly supportive
• No antibiotics!
• Eculizumab (in severe CNS involvement)

Question 4

What is the pathophysiology of erythema infectiosium?

Answer 4

• Caused by parvovirus B19 –> destroys reticulocytes
• Respiratory droplet spread (most adults have immunity)

Question 5

Describe the exanthem presentation of erythema infectiosium (aka 5th disease)?

Answer 5

“slapped cheek” rash on face - lacy reticular rash on extremities, spares palms, and soles

Question 6

What are some of the complications associated with erythema infectiousium?

Answer 6

• In Pregnancy: fetal loss
• Sickle Cell: aplastic crisis

Question 7

What is the etiology of hand foot and mouth disease?

What seasons is it most common?

Answer 7

Coxsackievirus type A virus

Summer and fall

Question 8

What is the other name for rubeloa?

Answer 8

Measles

Question 9

What are Koplic Spots?

Answer 9

Small red spots in buccal mucosa with blue-white pale center seen in rubeloa (measles)

Question 10

What exanthem is described as the “3-day rash”?

Describe the rash?

Answer 10

Rubella (German Measles)

pink light-red spotted maculopapular rash first appears on the face, spreads caudally to the trunk and extremities, and becomes generalized within 24 hours (lasts 3 days)

Question 11

Is rubella teratogenic?

Answer 11

Yes, can cause congenital syndrome including deafness, cataracts, TTP, neurocognitive delay

Question 12

What causes roseola?

Answer 12

Herpesvirus 6 and 7

Question 13

What is the pentad of thrombotic thrombocytopenic purpura?

Answer 13

• Fever
• Anemia
• Thrombocytopenia
• Renal insufficiency
• Neurologic deficits

Question 14

A 2-year-old boy presents to the hematology clinic with easy bruising and recurrent hemarthrosis. He has severe hemophilia A. Which of the following is the best treatment?

A) Desmopressin
B) Factor IX replacement
C) Factor VIII replacement
D) Platelet transfusions

Answer 14

Factor VIII replacement

Question 15

How is anemia defined?

Answer 15

Defined as low hematocrit and/or hemoglobin relative to normal values

Symptoms: weakness, fatigue, dyspnea on exertion

Physical exam: pallor, tachycardia, systolic flow murmur, jaundice, positive stool guaiac

May present as angina

Question 16

What is the most common cause of anemia in children?

Answer 16

Iron Deficiency Anemia

Question 17

A 2-year-old child presents with pallor, irritability, and poor dietary intake. Laboratory tests reveal a low hemoglobin level with microcytic and hypochromic red blood cells. What is the most likely diagnosis?

A. Iron deficiency anemia
B. Sickle cell anemia
C. Lead poisoning
D. Aplastic anemia

What is the treatment?

Answer 17

Iron Deficiency Anemia

Iron deficiency ⇒ low ferritin, low serum Fe, high TIBC

Oral Iron Supplementation

Question 18

A 12-year-old child with a history of sickle cell disease presents with fatigue, jaundice, and an acute drop in hemoglobin level. What is the most likely cause of these findings?

A. Iron overload
B. Aplastic crisis
C. Hemolytic crisis
D. Megaloblastic anemia

Answer 18

Aplastic Crisis

Question 19

Which diagnostic test is most helpful in differentiating between thalassemia and iron deficiency anemia in a child with microcytic anemia?

A. Bone marrow biopsy
B. Hemoglobin electrophoresis
C. Serum ferritin
D. Red blood cell count

Answer 19

Hemoglobin electrophoresis

Hemoglobin electrophoresis is a critical test for identifying hemoglobinopathies like thalassemia. This test evaluates the types and relative amounts of hemoglobin present in the blood. In thalassemia, abnormal forms of hemoglobin (like HbA2 and HbF) may be elevated, which can be detected by this method.

Question 20

A 6-month-old infant is brought to the clinic by his parents who are concerned about his slow growth and pale appearance. The infant is exclusively breastfed. Laboratory results show a hemoglobin of 9.5 g/dL, MCV of 70 fL, and a low reticulocyte count. Which of the following steps is most appropriate in the management of this infant’s condition?

A. Begin oral iron supplementation and dietary counseling.
B. Immediate blood transfusion.
C. Start B12 injections.
D. Refer for bone marrow biopsy.

Answer 20

Begin oral iron supplementation and dietary counseling

Question 21

A 9-year-old boy presents to the clinic with fatigue, pallor, and a sore tongue. His mother reports that he has become increasingly irritable and has been eating poorly. Laboratory results show hemoglobin of 10 g/dL, MCV of 110 fL, and a low reticulocyte count. The child’s diet is primarily vegetarian. Based on these findings, which of the following is the most likely diagnosis and the appropriate treatment?

A. Iron deficiency anemia; start oral iron supplements.
B. Vitamin B12 deficiency anemia; begin vitamin B12 supplementation.
C. Aplastic anemia; refer for bone marrow biopsy.
D. Thalassemia; perform hemoglobin electrophoresis.

Answer 21

Vitamin B12 deficiency anemia; begin vitamin B12 supplementation.

Question 22

A 2-year-old girl, previously healthy, presents with her parents to the emergency department. She has a history of progressive weakness and easy bruising over the last two weeks. Physical examination reveals significant pallor and petechiae on her lower extremities. Laboratory studies indicate a hemoglobin of 6.8 g/dL, white blood cell count of 3000/µL, and platelets of 20,000/µL. Which of the following is the most appropriate next step in management?

A. Start high-dose corticosteroids.
B. Immediate red blood cell transfusion.
C. Obtain a bone marrow biopsy.
D. Initiate oral iron supplementation.

Answer 22

Obtain a bone marrow biopsy

This scenario describes a child presenting with symptoms indicative of severe and sudden onset anemia, leukopenia (low white blood cell count), and thrombocytopenia (low platelet count). The combination of these symptoms—especially the presence of easy bruising (petechiae) and significant pallor—raises concern for a condition affecting the bone marrow’s ability to produce blood cells.

Question 23

A 6-year-old child with known sickle cell disease presents to the clinic for a routine follow-up. The mother reports that the child has had two painful crises in the past year, but currently has no complaints. The physical exam is unremarkable except for mild jaundice. Laboratory tests show hemoglobin of 7.5 g/dL, reticulocyte count elevated, and bilirubin increased. What is the most likely explanation for these findings, and what is an appropriate intervention to consider for long-term management?

A. Ongoing hemolysis; start hydroxyurea.
B. Iron overload; begin chelation therapy.
C. Vitamin deficiency; supplement with folate.
D. Aplastic crisis; administer a red blood cell transfusion.

Answer 23

Ongoing hemolysis; start hydroxyurea

Question 24

A 4-month-old infant is brought to the pediatric clinic by concerned parents due to poor feeding and developmental delay. The infant was born full-term via an uncomplicated vaginal delivery. On examination, the infant is noted to have frontal bossing and a protruded abdomen. Laboratory results show hemoglobin of 7 g/dL, MCV of 65 fL, and target cells on peripheral smear. What is the most likely diagnosis, and what confirmatory test should be performed?

A. Iron deficiency anemia; check serum ferritin levels.
B. Thalassemia major; perform hemoglobin electrophoresis.
C. Lead poisoning; test blood lead levels.
D. Hereditary spherocytosis; conduct osmotic fragility test.

Answer 24

Thalassemia major; perform hemoglobin electrophoresis