teaching files 2

8/12/2019 Teaching Files 2

1/23

Case I

A 6-month-old girl becomes ill with fever,

vomiting, and diarrhea for last four days

Her presentation in emergency is with shock

with severe pallor.

.


2/23

Examination

On arrival, her rectal temperature is 100.4F(38.0C), heart rate is 179 beats per minute,respiratory rate is 47 breaths per minute, andblood pressure is 66/18 mm Hg.

Growth parameters reveal that her weight isbelow the fifth percentile, her length is at the25th percentile, and her head circumference is atthe 10th percentile.

She is lethargic and hypotonic with diffuse pallor.Capillary refill time is prolonged at 4 seconds. Therest of the examination findings are normal.


3/23

Investigations

white blood cell count, 1.4 103/L(1.4

109/L) (neutrophils-segmented, 42%;

neutrophils-bands, 16%; lymphocytes, 20%;

monocytes, 20%; and basophils, 2%);

hemoglobin, 1.9 g/dL (19.0 g/L)

platelet count, 106 103/L(106 109/L)

corrected reticulocyte count, 0.2%; serum


4/23

sodium 143 mEq/L (143 mmol/L);

potassium, 3.7 mEq/L (3.7 mmol/L)

chloride, 111 mEq/L (111 mmol/L)

bicarbonate, 6 mEq/L (6 mmol/L)

blood urea nitrogen, less than 3 mg/dL (


5/23

More investigations

Viral studies and cultures for bacteria arenegative.

Bone marrow examination revealed vacuolated

hematopoietic precursors Stool pancreatic elastase levels were less than 10

g/g of feces

Southern blot analysis of blood and bonemarrow confirmed a mitochondrial DNA (mtDNA)deletion of approximately 4 kb, spanning the ND4gene to the CYTB gene.


6/23

Diagnosis

A diagnosis of Pearson syndrome may be suspectedwhen a child presents, usually in the first year of life,with any combination of the following:

refractory sideroblastic anemia (usually macrocytic)

pancytopenia

infection

chronic diarrhea with fatty stools

lactic acidemia, and metabolic acidosis


7/23

Diagnosis

. Bone marrow failure and exocrine pancreasinvolvement are prominent.

The extent of multiple organ involvement isvariable and includes hepatic, renal, cardiac, andendocrine failure.

A diagnosis is made when a childs bone marrowexamination reveals the characteristic vacuolatedhematopoietic precursors and a Southern blot

analysis of blood and bone marrow confirms amtDNA deletion.


8/23

Death in infancy is common and is usually due

to severe infection, metabolic crisis, liver

failure, or heart block.


9/23

DD

. X-linked sideroblastic anemia

Diamond-Blackfan anemia

Shwachman-Diamond syndrome Exposure to chloramphenicol and dietary

deficiencies of copper, phenylalanine, and

riboflavin.


10/23

Managment

There is no specific treatment available

Levocarnitine and coenzyme Q10 are given toenhance the function of residual respiratory

enzyme activity. Pancreatic enzyme replacement and

supplementation of fat soluble vitamins help

to alleviate the symptoms of pancreaticexocrine insufficiency.

No dietary restrictions are required.


11/23

management

The use of medications toxic to mitochondria,including chloramphenicol, aminoglycosides,linezolid, valproic acid, and nucleoside reversetranscriptase inhibitors, should be avoided.

The anemia is refractory, and patients may betransfusion dependent.

Prompt evaluation of fever, including parenteralantibiotics and blood culture

management of intermittent metabolic criseswith hydration and correction of electrolyteabnormalities are critical.


12/23

Prognosis

Pearson syndrome is often fatal in infancy or

early childhood (median survival time, 4 years).

The usual causes of death are bacterial sepsis due

to neutropenia, unremitting metabolic crisis, andhepatic failure.

The features of Pearson syndrome may change

over time. Some children may experience aspontaneous recovery from the hematologic and

pancreatic dysfunction.


13/23

lessons

Pearson syndrome is probably

underdiagnosed and must be considered in

infants and children with cytopenias

associated with failure to thrive, refractoryanemia, sepsis, acidosis, pancreatic

insufficiency, and renal or liver disease and in

infants with a history of hydrops fetalis.


14/23

Case 2

A previously healthy 4-months old boy is

brought with complaints of bright red urine in

his diaper two times in this week.

He was well until 5 days earlier, when he

developed a temperature of 100.9F (38.3C),

congestion, rhinorrhea, and cough.

.

.


15/23

History

His interest in breastfeeding has decreased,

although he continues to feed every 3 to 4 hours.

History is negative for vomiting, diarrhea,

irritability, excessive crying, or edema He was born at 38 weeks gestation, weighing

3,520 g. He has never been hospitalized or

undergone surgery. The family history is negativefor hematuria, end-stage renal disease, and

nephrolithiasis


16/23

Examination

he is happy and well-appearing

normal vital signs for age and normal

hydration status

The abdomen is soft and nontender, no

bruising or cutaneous trauma noted.

He is circumcised, with normal-appearing

external genitalia and There is a small amount

of orange-red, chalky residue in the diaper.


17/23

Labs

normal serum electrolyte, blood urea nitrogen,and creatinine levels.

The infants serum uric acid level was found to below at 2.1 mg/dL (125 mol/L) (reference range,2.4-6.4 mg/dL [143-381 mol/L]).

A dipstick urinalysis reveals a specific gravity of1.007, pH 5.0, and no protein, blood, glucose,leukocyte esterase, or nitrite

the microscopic examination reveals a fewamorphous urate crystals but no casts and 1 to 3red blood cells per high-power field.


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The urine calcium-creatinine ratio is

calculated to be 0.68 (normal for age,


19/23

Diagnosis

idiopathic renal hypouricemia, a renal tubular

disorder in which there is an isolated defect in

the tubular reabsorption of uric acid, leading

to hypouricemia and hyperuricosuria.


20/23

The discoloration of the diaper was due to thepresence of urate crystals, a frequent finding inmany otherwise healthy infants.

Normal among breastfed newborns in the firstfew days of life, when uric acid excretion is highand urine volumes tend to be low.

However, in older infants and children with red

urine or in patients with a personal or familyhistory of nephrolithiasis, over excretion of uricacid should be considered.


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Learning point

A urinalysis that indicates the absence of

blood by dipstick and red blood cells on

microscopic examination excludes hematuria,

as it did in this case.


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Managment

no specific therapy

Stones can be prevented in most patients byincreasing fluid intake and maintaining urinary

alkalinization. Allopurinol (a competitive inhibitor of

xanthine oxidase, the enzyme that catalyzes

the production of uric acid) may also behelpful in patients with recurrent stones andpersistent hyperuricosuria.


23/23

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