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pearls2
A low-birthweight infant presents to his pediatrician at 2 months of age. The mother states that the infant has not been eating well. On physical examination the infant is noted to be pale and tachycardic. The lungs are clear to auscultation and there is no hepatosplenomegaly. A complete blood count (CBC) shows a hemoglobin (Hgb) level of 6 g/dl. Which of the following is the most likely cause of anemia in this infant
Anemia of prematurity
 Anemia of prematurity occurs in low-birthweight infants approximately 1 to 3 months after birth.
 It is caused by the physiologic effects of the transition from fetal to neonatal life,
 as well as factors such as shortened red blood cell (RBC) survival,
 rapid growth, and frequent phlebotomy for blood tests.
 Hemoglobin (Hgb) levels in anemia of prematurity are below 7 to 10 g/dl.
 Clinical manifestations may include feeding problems, tachypnea, tachycardia, and pallor.
 Megaloblastic anemia of infancy is caused by a deficiency of folic acid and has its peak at 4 to 7 months of age.
 Infants with folate deficiency are irritable, have poor weight gain, and have chronic diarrhea.
 Newborns with sickle cell anemia rarely exhibit clinical manifestations until 5 to 6 months of age.
Acute sickle dactylitis (i.e., painful swelling of the hands and feet) is usually the first evidence that sickle cell disease is present in an infant.
 The thalassemias are a group of heritable, hypochromic anemias. a-Thalassemia
 is caused by abnormalities in the synthesis of the a chains of Hgb,
 and is manifested as microcytosis of the newborn [mean corpuscular volume (MCV) < 95 m3].
 Homozygous b°-thalassemia usually manifests as a severe, progressive hemolytic anemia in the second 6 months of life, requiring regular blood transfusion.
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A 7-year-old child presents to his physician with complaints of headache and a stiff neck. A lumbar puncture is performed, and analysis of the cerebrospinal fluid (CSF) is done. Which of the following CSF findings characterizes a viral, rather than a bacterial, meningitis
normal glucose
 It is more common for babies to get meningitis than adults.
 The symptoms maybe fever, nausea, or vomiting.
 They might also have a loss of appetite and sleepiness.
 Babies could have blotchy or pale skin.
 Other symptoms are moaning cry when handled and uncontrollable jerking.
 Symptoms for babies may even include a floppy body.
 Viral or aseptic meningitis usually presents with a normal to slightly elevated [not substantially increased ] protein concentration.
 The lactate concentration is not elevated
 . Rather, glucose and lactate concentrations are both normal.
 No organisms are seen on Gram's stain or routine cultures. White blood cell (WBC) count in the cerebrospinal fluid (CSF) is usually 100 to 700/ ml, with polymorphonuclears early on [before 48 hours ], then lymphocyte predominance.
 Pressures are normal.
 Diagnosis is usually based on CSF characteristics,
 including normal glucose and absence of bacteria on culture.
 Viruses (eg, enteroviruses) are occasionally isolated directly from CSF or from other tissues but are identified in fewer than half the cases.
 They can be precisely identified by polymerase chain reaction techniques, which detect specific viral DNA in CSF.
 Alternatively, an increase in specific antibodies in paired acute and convalescent sera can be detected, but this technique is not practical for rapid diagnosis.
 Cultures (eg, from the nasopharynx or stool) and attention to epidemic agents in the community may help.
 Because of public health implications, serum should be drawn and preserved whenever the diagnosis of encephalitis or aseptic meningitis of uncertain etiology is first suspected. Information regarding more precise viral diagnosis can be obtained from local departments of health.
 Viral Meningitis is more common than the bacterial form,
 but generally less serious -
 although it can be very debilitating.
 It can be caused by many different viruses.
 Some are spread between people by coughing or sneezing, or through poor hygiene.
 Others can be found in sewage-polluted water.
 the incubation period can be up to three weeks.
 In mild cases of viral meningitis, people would not even go to their doctor.
 However, as the symptoms are similar to the bacterial form, someone with a severe case of viral meningitis will need to be admitted to hospital for test to find out which form they are suffering from.
 The most common causes or viral meningitis are coxsackie and echovirsuses (known as enteroviruses).
 It can also develop as a result of infection with
herpes simplex,
measles, polio
or chickenpox.
 Mumps meningitis used to be a complication of mumps, but has virtually been eliminated following the introduction of the MMR (Measles, Mumps and Rubella).
Coxsackie
 coxsackie:Found in the intestines of humans, and therefore in faeces and sewage polluted water, these viruses are the most common causes of viral meningitis. Most cases occur in the summer months.
Herpes Simplex
 The herpes virus is widespread and usually produces cold sores, but can occasionally cause viral meningitis or encephalitis, which is inflammation of the brain itself.
 When left untreated, meningitis of any etiology, but particularly with the pyogenic and granulomatous forms, may lead to widespread destruction of the brain
 there is marked hydrocephalus with little remaining cortex.
 The only normal appearing structures are the basal ganglia and thalamus.
 Characteristically, meningitis, through retrograde spread, often leads to ependymitis (inflammation of the ependymal lining of the ventricular system).
Consequently, hydrocephalus develops due to blockage of CSF outflow at the level of the aqueduct of Sylvius or the basal cisterns.
 Cortical destruction results from both involvement of penetrating vessels and pressure atrophy.
 The white matter is often intensely gliotic.
 In its end-stage form, patients who survive severe episodes of meningitis are often left with
 mental retardation,
 paralysis,
 blindness
 and/or deafness.
 the rare instance in which ependymitis is the primary pathologic process.
 Ependymitis is evidenced by periventricular congestion and hemorrhage.
 Also, note the virtual absence of a meningeal reaction.
 Cases of primary ependymitis are usually associated with septicemia
  rare instance in which ependymitis is the primary pathologic process. Ependymitis is evidenced by periventricular congestion and hemorrhage. Also, note the virtual absence of a meningeal reaction. Cases of primary ependymitis are usually associated with septicemia.
Serum C-reactive protein levels reliably distinguish between Gram stain-negative bacterial meningitis and viral meningitis in children,
 Not all different types of meningitis have a cure.
 Bacterial meningitis is treated with sulfa drugs and antibiotics.
 These antibiotics include penicillin, ampicillin, and cephalosporin.
 Tuberculous meningitis is treated with streptomycin and antituberculous.
 There is no effective treatment for viral meningitis though.
 Only your immune system can fight viral meningitis.
 Rest and fluids are used to recover from viral meningitis usually.
 One in ten people carry the bacteria that causes meningitis usually in the back of the throat.
 However, the bacteria does not normally pass into the bloodstream.
Meningitis is caused by bacteria, viruses, fungi, and microbes[see meningitis page].
Viral meningitis is caused by a number of different viruses.
 Most people are exposed to the viruses that cause viral meningitis, but few develop viral meningitis.
People with sickle-cell anemia have more of a risk to get meningitis.
 Children have a greater risk of receiving viral meningitis if they have mumps or herpes virus infection.
 Maybe in the future, we can create a vaccination to prevent all types of meningitis so we do not have to worry about it like other diseases now.
 menincoccal meningitis
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 Mollaret's (recurrent) meningitis is characterized by
 repeated episodes of fever (up to 104°F),
 meningismus,
 and severe headache
 separated by symptom-free intervals.
 Individual attacks are sudden,
 with signs and symptoms reaching maximum intensity within a few hours.
 Headache, neck pain, generalized muscle aches, and neck stiffness usually persist from 3 to 6 days,
 but may be present for up to 3 or more weeks.
 Following a number of recurrences, which can span a period of years, the disease suddenly disappears.
 The long-term health of the patient seems not to be adversely affected.
 Transient neurologic abnormalities (seizures, diplopia, pathologic reflexes, cranial nerve paresis, hallucinations, and coma) occur in as many as 50% of cases
 Mollaret's meningitis is a syndrome rather than a disease.
 As such, the syndrome of Mollaret's meningitis appears to have multiple etiologies.
 Presently, herpes simplex type II, and to a lesser extent type I, appear to be etiologic in most cases.
 Because of the rarity of this syndrome, there are no large clinical trials comparing one therapy against another.
However, acyclovir (intravenous or oral) or valacyclovir (oral only) are worthy of consideration for both therapy and prophylaxis.
 A pain killer is generally administered during the first several days of an attack to reduce patient suffering from the severe headaches, stiffness, and overall body aches produced by the onset of the disease.
Points to Remember
 Mollaret's meningitis is usually a benign (but painful) self-limited, recurrent, and often febrile meningitis.
 Transient neurologic deficits (seizures, cranial nerve paresis, pathologic reflexes) occur in 50% of cases.
 Mollaret's may be caused by herpes simplex type II; acyclovir may play a role in prophylaxis and therapy.
 Anecdotal patient information as well as scientific evidence suggests viral meningitis may be triggered by reduced immune system function, allergic response, stress and depression, as well as exposure to the sun. Recurrent meningitis sufferers should avoid becoming fatigued or stressed and should avoid excessive exposure to the sun
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Primary Intracranial Tumors
 Gliomas are the most common intracranial neoplasm, accounting for half of all primary intracranial neoplasms .
 The remainder consist of
 meningiomas,
 pituitary adenomas,
 neurofibromas,
 and other tumors.
 Certain tumors, especially
 neurofibromas,
 hemangioblastomas,
 and retinoblastomas,
 may have a familial basis, and congenital factors bear on the development of craniopharyngiomas.
 Tumors may occur at any age, but certain gliomas show particular age predilections
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 The clinical manifestations are listed here;
 hepatomegaly,
 splenomegaly,
 hyperbilirubinemia.
 Generalized diffuse infection with CMV virus;
 the various manifestations you see here; cerebral calcifications.
 A big deal is made by the difference of these calcifications and toxoplasmosis, and it’s a good Board question.
 These are supposedly periventricular whereas in toxoplasmosis they are more diffuse.
 But that’s not hard and fast.
 The other manifestations are hemolytic anemia and interstitial pneumonia.
 This is a picture of a baby with severe involvement with marked petechial lesions throughout.
 Congenital anomalies with CMV compared to, for example rubella, actual anomalies are not that clear-cut.
 Cardiovascular anomalies, even though there is heart disease, it has no real pattern and it can involve all types of heart defects.
 Whereas with rubella you have some very specific cardiac defects.
 The other findings;
 hypospadias,
 gastrointestinal things such as duplications and musculoskeletal defects.
But in general, the main manifestations of CMV are acute active infection involving what I showed you previously.
 The diagnosis of CMV historically was looking for inclusion cells in the urine, and I’m sure nobody these days even knows what that is.
 That inclusion cells were epithelial cells, renal tubular epithelial cells, infected with virus and giving a typical cytopathic effect.
So the main method of diagnosis is viral isolation.
 But the important thing in a newborn baby is you need to do this immediately.
 Two weeks later you don’t know whether that infection occurred after birth and therefore not a congenital infection.
 So one of the major things is that if you suspect congenital infection and CMV, look for virus immediately
 . Now in this day and age PCR can also be done as can direct antigen tests, but the definitive test is virus isolation.
 T he places are urine, throat, CSF and really should add blood, buffy coat of the blood as well.
 The next is serology. IgM … we’ve gone overboard with IgM assays and the right assay IgM positive indicates recent infection and is a very useful test.
 But there are frequent false positives and there are occasional false negatives.
The false negatives are when there are very high IgG values.
 But false positives actually are much more common, both in pregnant women and also occasionally in babies. So you really want to go for culture.
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 Many commonly used drugs (including nonprescription drugs) should be avoided in the nursing mother because they are detectable in breast milk and may cause effects in the infant.
 The polyene antifungal agent, nystatin, is used by local administration in candidal infections of the oropharyngeal cavity and the urogenital system (e.g., vaginal yeast infections).
 By this mode of administration, nystatin is not absorbed into the systemic circulation and is not present in breast milk.
 All of the other drugs listed necessitate systemic absorption.
 Drugs to be avoided in the nursing mother include central nervous system (CNS)-active drugs [e.g., stimulants and depressants, including benzodiazepines, ethanol, and amphetamine
 , certain antibiotics [tetracyclines quinolones],
 the methylxanthines [caffeine, theophylline ],
 the antithyroid drugs [methimazole ,
 propylthiouracil], and the glucocorticoids.
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 Werdnig-Hoffmann disease is a spinal muscular atrophy of unknown cause.
 It is inherited in an autosomal recessive fashion. Infants can be symptomatic at birth.
Sparing of the extraocular muscles and sphincters is characteristic.
Fasciculations are a sign of denervation of muscle and are best seen in the tongue.
Infants assume a flaccid "frog-leg'' posture.
 Most die by 2 years of age.
 A neonatal form of myotonic dystrophy appears in infants born to mothers with myotonic dystrophy.
 Clubfoot and contractures are common.
 Fasciculations are not seen. Infant botulism has a peak onset at 2 to 6 months of age.
 Sources for spores include honey, corn syrup, soil, and dust.
 Infantile myasthenia gravis can be transient—as in those infants born of mothers with myasthenia gravis—or, very rarely, congenital.
 Fasciculations are not seen and the extraocular muscles are not spared.
 Duchenne's muscular dystrophy is rarely symptomatic at birth.
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Communicable Disease Fact Sheets
--------------------------------------------------------------------------------
 AIDS and HIV
 Hepatitis B
 Rabies
 Arboviral Encephalitis
 Hepatitis C
 Ringworm (Tinea)
 Chickenpox
 Herpes
 Rubella
 Chlamydia
 Histoplasmosis
 Salmonellosis
 Conjunctivitis ("Pink Eye")
 Impetigo
 Scabies
 Cryptosporidiosis
 Kawasaki
 Scarlet Fever
 Cytomegalovirus (CMV)
 Legionellosis
 (Legionnaire Disease)
 Shigellosis
 Diphtheria
 Lyme Disease
 Strep Throat
 E. coli O157:H7
 Malaria
 Syphilis
 Fifth Disease
 (Erythema Infectiosum)
 Measles
 Toxoplasmosis
 Giardiasis
 Meningococcal Disease
 Tuberculosis
 Gonorrhea
 Mononucleosis
 Typhoid Fever
 Haemophilus influenzae type b (Hib) Disease
 Mumps
 Viral Meningitis
 Hand, Foot, and Mouth Disease (Coxsackievirus)
 Mycoplasma Warts,
 Genital
 Head Lice Pertussis (Whooping Cough)
 West Nile Virus
 Hepatitis A
 Pneumococcal Disease
 Hepatitis B Carrier
 Psittacosis
_____________________________________________________________________________________________________________________
Phenylketonuria (PKU) is caused by a deficiency in phenylalanine hydroxylase.
 The normal pathway is disrupted, so phenylalanine and other metabolites accumulate and cause brain damage.
 Clinically, affected infants are
 blond,
 with fair skin
 and blue eyes.
 A mild eczematous rash disappears with age.
 Vomiting can be confused with pyloric stenosis.
 Mental retardation is usually severe.
 The infants have a musty, mousey odor of phenylacetic acid.
Screening is recommended after 72 hours of age and after feeding of proteins.
 Early institution of a diet low in phenylalanine is essential in preventing brain damage.
Women who have PKU and want to have children should go on a low-phenylalanine diet before conception and throughout pregnancy to reduce the risk of spontaneous abortion and birth defects.
The blood phenylalanine levels should be kept below 10 mg/dl throughout pregnancy.
 Pregnant women with PKU and phenylalanine levels greater than 10 mg/dl have a higher risk of spontaneous abortions.
 Infants born to such mothers may have
 mental retardation,
 microcephaly,
 and/or a congenital heart anomaly.
 Blood levels of 5 mg/dl are below the risk level.
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 Croup, or laryngotracheobronchitis, is most common between 6 months and 6 years of age.
Caused primarily by parainfluenza virus,
it typically presents with prodromal symptoms of an upper respiratory infection.
 The child then develops fever and a brassy, barking, seal-like cough, with intermittent inspiratory stridor.
 Acute respiratory distress can develop.
 Pertussis usually occurs in unimmunized infants and is usually preceded by a prodromal catarrhal stage with conjunctivitis.
 Spasms of coughing end with an inspiratory whoop
 . In younger infants, the whoop is not present and the signs are more subtle (e.g., apnea and cyanosis).
 Acute epiglottitis is more common in the 3- to 7-year age-group.
 Drooling is usually present, but the barking cough is absent.
Bronchiolitis and asthma can present with retractions of the intercostal muscles and nasal flaring, but wheezing is usually present.
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 Alport's syndrome is the most common of the hereditary nephritides.
 Patients develop glomerulonephritis that progresses to renal failure.
 Some patients develop hearing loss.
 Approximately 10% have eye abnormalities such as cataracts.
Alport's syndrome—glomerulonephritis
 Leopard syndrome is autosomal dominant.
 It consists of
 lentigines,
 electrocardiogram (ECG) abnormalities,
 ocular hypertelorism,
 pulmonary stenosis,
 abnormal genitalia,
 growth retardation,
 and sensorineural deafness.
 Pendred's syndrome is an autosomal recessive disorder
 characterized by deafness and goiter.
 The goiter appears at puberty and, although most patients are
 euthyroid,
 hypothyroidism can occur.
 Usher's syndrome is characterized by
 deafness,
 mental retardation,
 seizures,
 retinitis pigmentosa,
 and cataracts.
 Waardenburg's syndrome is autosomal dominant.
 Affected persons have a
 white forelock,
 patches of hyperpigmentation,
 defective hearing,
 and lateral displacement of the inner canthi.
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Principles of Newborn Screening
Disorders in which symtoms would not be clinically present until irreversible damage occurred and for which there is an effective treatment.
Prevalence of the disorder in the population.
Simple collection method.
Reproducible with few false positives/negatives..
High benefit-to-cost ratio.
Means of follow up of abnormal results.
Specimen Collection
Dried filter paper blood spots.
Infant < 72 hrs of age and preferably after 24 hours of protein feeding.
Obtained prior to blood transfusion.
Avoid cross-contamination.
Problems with early discharge.
State Mandated Newborn Screening
PKU and Congenital Hypothroidism -- all 50 states.
Galactosemia - 44 states; maple syrup urine disease - 23 states; homocystinuria - 21 states; biotinidase deficiency - 16 states; sickle cell disease - 42 states; tyrosinemia - 7 states.
Other states have added congenital toxoplasmosis, congenital adrenal hyperplasia, cystic fibrosis.
California Newborn Screen:
 PKU
 Galactosemia
 Hypothyroidism
 Sickle Cell and other Hemoglobinopathies
Metabolic Disorders
PKU
 Amino acid disorder
 Enzyme deficiency - phenylalanine hydroxylase
 Failure in conversion of phenylalanine to tyrosine
 Incidence: 1:12,000 live births in US
 Accumulation of phenylalanine:
 Classic PKU => 20 mg/dL with normal or reduced level of tyrosine
 Atypical PKU = 12-20 mg/dL
 Mild persistent hyperphenylalaninemia=levels 2-12 mg/dL
 Can result from deficiency of cofactor tetrahydrobiopterin (BH4)
 Symptoms
 Developmental delay
 Severe mental reatrdation
 Seizures
 Autism
 Eczema
 Hyperactivity
 Aggressive behavior
 Treatment
 Phenylalanine restricted diet instituted by 3 weeks of age
 Frequent monitoring of blood levels and diet adjustments
 Cofactor defects require BH4 replacement and neurotransmitter precursors L-dopa and 5- hydroxytryptophan
 Outcome
 Early treatment prevents mental retardation and neurologic abnormalities, learning disabilities still present
 Continuation of diet indefinitely is recommended to prevent decreases in IQ and maternal PKU (microcephaly, congenital heart disease, IUGR)
 Treatment of cofactor deficiencies has not prevented the mental retardation or neurologic abnormalities
Congenital Hypothyroidism
 Incidence in US: 1:3,600-5,000 live births
 Measure T4/TSH -- if levels are below lab cutoff, repeat specimen requested
 10% cases can be missed by sampling errors
 Normal variations in premature, maternal antithyroid medication, exposure to topical iodine,hypoalbuminemia -- test may need to be repeated
 Symptoms
 Mental retardation
 Neurologic abnormalities
 Metabolic symptoms of hypothyroidism
 Treatment
 L-thyroxine to maintain T4 levels in the upper half of the normal range
 Treatment within first 3 months of life associated with prevention of mental retardation and complications of the disease
Galactosemia
 Prevalence 1:40,000 live births
 Deficiency of galactose-1-phosphate uridyltransferase
 Symptoms of untreated galactosemia
 Lethargy
 Feeding intolerance
 Vomiting
 Hyperbilirubinemia
 Liver dysfunction with coagulopathy
 25% will develop sepsis in first 1-2 weeks if untreated
 Screening: measure galactose and galactose-1-phosphate; confirmation by measurement of the enzyme in erythrocytes
 Treatment
 Dietary lactose restriction at time of diagnosis
 Evaluate for sepsis immediately and treat promptly to prevent complications of mental retardation, cataracts, and cirrhosis
 Outcome
 Speech abnormalities
 Behavior problems
 Visual perceptual learning abnormalities
 Ovarian failure (recently described complication in girls)
 Three other inborn errors of galactose metabolism are known
 Variant forms of transferase deficiency occur with 10-35% of normal transferase activity. baby usually asymptomatic
 Galactokinase deficiency: incidence 1:1 million live births
 Cataracts
 Uridinediphosphate-galactose-4-epimerase deficiency: asymptomatic or have classical galactosemia
Sickle Cell Disease and other hemoglobinopathies
 Includes hemoglobin SS disease, hemoglobin SC, and sickle-thalassemaia -- all result from abnormal Beta-chains of hemoglobin.
 Incidence in blacks approx. 1:400
 Symptoms
 Severe anemia
 Hypoplastic crises induced by infection
 Overwhelming sepsis
 Pneumonia or meningitis
 Sudden and massive splenic sequestration
 Chronic debilitation
 Screening: hemoglobin electrophoresis by cord blood or dried filter paper blood spot. No false positives seen. Early diagnosis may not effect outcome of this disease. May afford early treatment of complications and allow for genetic counseling and reproductive choices
Glucose-6-Phosphate Dehydrogenase Deficiency
 Incidence: 1:100-1:10 for Mediterranean, African and American Black; 1:50-1:33 for Southeast Asian
 Sex-linked affecting primarily males; females variably affected
 Hemolytic disorder -- enzyme deficient RBCs are unable to protect against oxidative effects of infection or certain drugs where accumulation of peroxides causes breakdown of red cell membrane, enzymes and hemoglobin
 Severe hemolysis and hyperbilirubinemia is seen only in Caucasions and Asians; blacks less severely affected
 Treatment
 Prevent kernicterus by managing hyperbilirubinemia with exchange transfusion or phototherapy.
 Replace red cells if significant anemia
 Screening is by fluorescent spot test which measures the absence of the enzyme; confirm diagnosis by quantitative analysis
Gamma-Glutamyl Cycle Disorders
 Glutathione (GSH) is an intermediary in the gamma-glutamyl cycle, normally found in erythrocytes in high concentrations
 Role of GSH: transport of amino acids across cell membranes and reductant of toxic peroxidases, protecting hemoglobin against destructive effect of oxidation
 Several Gamma-Glutamyl disorders associated with decreased levels of GSH
 Symptoms
 Vomiting
 Diarrhea
 Abdominal pain
 If untreated congenital non-spherocytic anemia, metabolic acidosis, or pyroglutamic aminoaciduria
 Autosomal recessive
 Screening spot test: measures the presence of reduced glutathione
Congenital Adrenal Hyperplasia
 Autosomal recessive disorder in the biosynthesis of adrenal corticoids due to a deficiency of one of several enzymaic systems required for complete steroid biogenesis
 Most common form of CAH is due to 21-hydroxylase deficiency (90% of cases); in 2/3 increased androgen production
 Females: ambiguous genitalia and salt-losing crises. Milder forms -- premature sexual hair development, acne, hirsutism, acceleration of growth
 Incidence: 1:10000-1:15000 live births; higher in southwestern Alaska Eskimos
 Screening test measures level of 17-hydroxyprogesterone in the dried filter paper blood spot. Affected infants have high levels.
 False positives seen in prematurity and low birth weight, also illness, early screening (<24 hrs of age)
 Rationale for screening: early treatment to prevent complications seen in undiagnosed affected newborns, incorrect sex assignment in females, prevention of salt losing crisis
Maple Syrup Urine Disease
 Deficiency of branched--chain ketoacid dehydrogenase that results in the accumulations of the branched-chain amino acids leucine, isoleucine and valine and their respective ketoacids
 Incidence: 1:200,000 live births
 Infants appear normal at birth; if untreated, by end of first week develop feeding intolerance, vomiting and lethargy. Progresses to severe ketoacidosis and death. If survives the neonatal period, mental retardation and neurologic impairment develop. Milder form also exists.
 Screening: test for leucine by bacterial inhibition assay on dried blood filter paper
 All deaths and morbidity can not be prevented since results of test may not be available soon enough
 Treatment: diet restriction; peritoneal dialysis may be necessary in ketoacidosis
Homocystinuria
 Deficiency of enzyme cystathionine synthase that catalyzes the conversion of homocysteine to cystathionine, with accumulation of toxic levels in blood or urine
 Incidence: 1:100,000-1:200,000
 Untreated can lead to mental retardation, marfanoid body, dislocation of lenses of eye, osteoporosis, thromboembolic disease
 1/2 are pyridoxine sensitive
 Screening test measures methionine in dried filter paper specimen. May not have rise in methionine in first few days -- confirmation by blood and urine amino acids
 Treatment with pyroxidine is effective for that form of the disorder, also, methionine restricted diet
Biotinidase deficiency
 Enzyme necessary for recycling of biotin which activates the four mitochondrial carboxylases
 Incidence: 1:40:000
 If untreated, patients present in early months to years with alopecia, skin rashes, fungal skin infections, seizures, developmental delay, hypotonia, ataxia, hearing deficit, and visual abnormalities. Organic aciduria and ketoacidosis can occur later.
 Screening : colorimetric assay for biotinidase on dried filter paper blood spot. Confirmation of diagnosis by serum levels
 Treatment with oral biotin eliminates some of physical and neurologic abnormalities
Cystic fibrosis
 Incidence: 1:2000 Caucasian
 Most common lethal inherited metabolic disorder in whites
 Causes severe pulmonary disease and pancreatic insufficiency, hepatic cirrhosis
 Autosomal recessive
 Screening
 Measurement of immunoreactive trypsin (IRT) in the dried filter paper blood spot. Affected newborns have elevated levels.
 Second test is usually requested in 2 weeks if first positive.
 If second test positive, infant referred for sweat test for definitive diagnosis.
 Increased false negative rate in infants with meconium ileus; 5%-10% with cystic fibrosis may have normal IRT when first tested.
 Some recommend combination of IRT, sweat test and genetic mutation analysis for primary or recall testing. One study showed increased incidence of false positives using the IRT/sweat test protocol vs IRT/DNA test -- costs were similar
 Does early detection prevent mortality and morbidity?
 Proposed benefits: shorter hospitalization, better weight gain, fewer chest infections, identification of couples at risk for counseling
 Risks: psychological stress for families awaiting diagnosis, possible errors in diagnosis, complications of early antibiotic therapy
Toxoplasmosis
 Toxoplasma gondii -- parasite that can cause intrauterine infection with transmission to fetus by transplacental-fetal hematogenous route; organism invades brain, eye and striated muscle forming tissue cysts
 Incidence of congenital infection 1:1000 live births
 Transmission rate increases with progression of gestation; infections transmitted during early gestation cause more severe fetal effects -- abortion, stillbirth, teratogenesis.
 In fetus or neonate typically CNS and/or eyes involved. Classic triad: obstructive hydrocephalus, chorioretinitis, intracranial calcification.
 Risk factor - cats vector, unpasteurized milk , undercooked meats, blood transfusion
 Screening-measurement of toxoplasma-specific IgM in the dried filter paper blood spot. Identified infants referred to ID specialists of evaluation and early institution of therapy
 No studies yet available to determine benefits of early detection and treatment
Conclusions
Changes in newborn screening programs
 Addition of several newer disorders
 Duchenne Muscular Dystrophy
 Congenital AIDS
 Neuroblastoma
 Alteration in basic principles
 Uncertainty about true benefit to early detection and therapy
Advances in molecular genetics
 Diagnosis by DNA mutation analysis, using allele-specific oligonucleotide probes
Issues related to false positives/negatives
 Need for repeat specimens
 Caution in making diagnosis
 Screening tests are not diagnostic -- additional definitive testing needed
 Necessary to confirm or rule out
Problems with early discharge
 Need for close follow up and repeat specimens
 Insufficient time for ingestion of protein for amino acid elevations
 Still mandatory that blood specimens be obtained prior to discharge and repeated in 2 weeks
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Physical Maturity
Sign
|
-1
|
0
|
1
|
2
|
3
|
4
|
5
|
Skin
|
Sticky, friable, transparent
|
Gelatinous red, translucent
|
Smooth pink, visible veins
|
Superficial peeling and/or rash, few veins
|
Cracking, pale areas, rare veins
|
Parchment, deep cracking, no vessels
|
Leathery, cracked, wrinkled
|
Lanugo
|
None
|
Sparse
|
Abundant
|
Thinning
|
Bald areas
|
Mostly bald
|
 |
Plantar Creases
|
Heel-toe 40-50 mm = -1, <40 mm = -2
|
Heel-toe >50 mm, no creases
|
Faint red marks
|
Anterior transverse crease only
|
Creases over anterior 2/3
|
Creases over entire sole
|
 |
Breast
|
Imperceptible
|
Barely perceptible
|
Flat areola, no bud
|
Stippled areola, 1-2 mm bud
|
Raised areola, 3-4 mm bud
|
Full areola, 5-10 mm bud
|
 |
Eye & Ear
|
Lids fused, loosely = -1, tightly = -2
|
Lids open, pinna flat, stays folded
|
Slightly curved pinna, soft with slow recoil
|
Well-curved pinna, soft but ready recoil
|
Formed and firm, with instant recoil
|
Thick cartilage, ear stiff
|
 |
Genitals, male
|
Scrotum flat, smooth
|
Scrotum empty, faint rugae
|
Testes in upper cannal, rare rugae
|
Testes descending, few rugae
|
Testes down, good rugae
|
Testes pendulous, deep rugae
|
 |
Genitals, female
|
Clitoris prominent, labia flat
|
Prominent clitoris, small labia minora
|
Prominent clitoris, enlarging minora
|
Majora and minora equally prominent
|
Majora large, minora small
|
Majora cover clitoris and minora
|
 |
Differential Dx of Clotting Disorders
Long PTT + normal PT + normal platelets + normal bleeding
|
Factor VIII, IX, XI, XII
|
Long PTT + normal PT + normal platelets + long bleeding time
|
Von Willebrand's Disease
|
Long PTT + long PT + normal platelets
|
Vitamin K deficiency
|
Long PTT + long PT + decreased platelets
|
DIC or generalized coagulopathy
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Normal PTT + long PT
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Factor VII
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Normal PTT + normal PT + normal platelets + normal bleeding time + bleeding especially umbilicus
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Factor XIII
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Normal PTT + normal PT + low platelets
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ITP, aplasia, leukemia, etc.
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Many petechia and normal platelets
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HSP, CMV, etc.
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Differential Diagnosis of Hyperbilirubinemia
Indirect Hyperbilirubinemia
Direct Hyperbilirubinemia
Differential Dx of Anemia
General Diagnostic Flowchart
Differential Dx by Time of Occurence
Early Neonatal Period
 Fetal hemorrhage: vasa previa, placenta previa, abruption, amniocentesis, incision of placenta at C-section.
 Fetomaternal transfusion (check Kleihauer-Bettke test).
 Twin-to-twin transfusion.
 Early cord clamping (failure of normal placentofetal transfusion), and fetoplacental transfusion (baby held above mother).
 Acute or chronic fetal hemolysis: Rh incompatibility, alpha-thalassemia, intrauterine infection.
 Neonatal hemorrhage: ruptured liver or spleen, fractures, intracranial, pulmonary, gastrointestinal, from umbilical cord, subaponeurotic, extensive hematoma or bruising.
 Intrauterine bone marrow failure (e.g. Diamond-Blackfan).
 Iatrogenic.
Late Neonatal Period
 Iatrogenic.
 Chronic hemolysis: Rh, ABO, red cell defects, enzyme defects, hemoglobinopathies, infection.
 Sepsis.
 Bleeding diastheses: Vitamin K deficiency, DIC, intraventricular hemorrhage.
 Physiologic anemia of prematurity ("early anemia"), due to deficient erythropoiesis and diminished red cell survival.
 Late anemia of prematurity, due to iron deficiency (usually after 8 weeks).
 Vitamin E deficiency hemolytic anemia.
 Possible folate and Vitamin B-12 deficiencies.
 Bone marrow failure.
Differential Dx by Red Cell Characteristics
 Microcytic Hypochromic
 Iron deficiency
 Thalesemia
 Lead toxicity
 Chronic disease
 Sideroblastic
 Heredity
 Acquired
 Toxin induced
 Proliferative disease
 Pyridoxine-responsive
 Transferrin deficiency
 Macrocytic
 B-12, folate deficiency
 GI, malabsorption: NEC, short gut, bowel disease
 Folate deficiency (e.g. goats milk)
 Pernicious anemia
 Tape worm (Diphyllobothrium latum)
 Normocytic Normochromic, Increased Retics
 Acute blood loss
 Congenital
 Red cell membrane: spherocytosis, eliptocytosis, stomatocytosis, poikilocytosis (infantile form usually resolves), acanthocytosis (can be associated with A, B lipoproteinemias)
 Hemoglobinopathy: C, S, E, D
 Enzymes: G6PD, pyruvate kinase (others very rare)
 Infection: toxin (Clostridia), DIC, viruses, malaria
 Immune: ABO, Rh, lupus, idiopathic, drugs, JRA
 Hypersplenism
 Mechanical: heart valves, patches, DIC
 HUS, March Hgb syndrome
 Giant hemangioma
 Drugs
 Burns, blister cells
 Normocytic Normochromic, Decreased Retics
 Congenital: Fanconi's, Diamond-Blackfan
 Acquired aplastic: idiopathic, Gaucher's, osteopetrosis, leukemia, radiation, chemotherapy
 Pure red cell: hereditary enzyme abnormality (congenital hemolytic with hypoplastic crises)
 Transient erythroblastopenia
 Thymoma (usually in adults)
G6PD Deficiency
 Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme which allows the red cells to make NADPH. NADPH is used to break down free radicals (oxidants) in the cell.
 When NADPH is depleted, Hgb becomes oxidized and denatured.
 The denatured Hgb is unable to bind O2 (O2 is bound by Hgb in the reduced form) and appears as a Heinz body, which is removed by the spleen.
 The normal G6PD enzyme is referred to as Gd B. Other types are:
 Gd A+ : Normal variant (20% of all blacks)
 Gd A- : Hemolytic variant, decreased catalytic activity
 Gd Med: Markedly decreased catalytic activity
Gd B, Gd A+: Half life is about 60 days, however normal cells retain enough activity during life span to maintain NADPH as GSH (glutathione - reduced) in the face of oxidant stress.
Gd A-: Half-life is about 13 days. Young cells have normal activity while old cells are grossly deficient. With hemolysis due to stress/oxidants, the bone marrow is stimulated to make new cells by increasing reticulocytosis, these new cells have adequate G6PD and hemolysis abates without transfusion. Thus, after an acute hemolytic event, G6PD levels are normal in this variant.
Gd Med:
 These individuals have very unstable Hgb, with very low levels of enzyme activity in the mature cells.
 The minimal amount of oxidant stress in routine life is not adequate to induce spontaneous lysis; however, any additional oxidant stress (e.g. drugs, infection, and in some individuals, fava beans) can cause continued and non-relenting hemolysis, with destruction of the entire red cell population. Unlike Gd A-, these individuals cannot make RBCs with adequate activity and require multiple transfusions to stop the hemolytic crisis.
Pyruvate Kinase
 The absence of pyruvate kinase (PK) causes decreased ATP, which is used in red cell mitochondrial phosphorylation.
 Absence results in decreased K+ and H2O and increased Ca++ in the cells, in turn leading to a change of shell shape and rigidity.
 The result is the presence of "frilly" cells with inclusion bodies that have early slow degeneration.
 (The hypoxemic nature of the circulation within the spleen further increases rigidity and lysis and thus splenectomy is often indicated.)
Fanconi's Syndrome
 Onset of anemia: mean age 8 years.
 Syndrome includes
 microcephaly,
 microphthalmia,
 absent thumbs,
 hyperpigmentation,
 cafe au lait spots,
 short status,
 renal anomalies,
 and heart anomalies.
 Associated with leukemia.
 Autosomal recessive.
Diamond-Blackfan Syndrome
 Onset of anemia: newborn to 1 month.
 Associated with
 thrombosis,
 web neck,
 cleft lip,
 short stature,
 increased fetal Hgb,
 pure red cell aplasia,
 leukemia.
 Autosomal recessive.
Abdominal Masses in the Newborn
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Dysmorphic IEM Presenting in the Neonatal Period
Most patients with IEM do not have dysmorphic features, but there are several important exceptions:
Peroxisomal disorders - such as Zellweger's cerebrohepatorenal syndrome. Patients are dysmorphic with characteristic CNS abnormalities on MRI, cataracts, hepatomegaly, and multicystic dysplastic kidneys.
Fatty acid oxidation disorders, glutaric acidemia type II - patients may have dysmorphic features similar to Zellweger's, hypertrophic cardiomyopathy, and multicystic dysplastic kidneys.
Menke's disease - mild dysmorphic features, hypopigmentation, and kinky, brittle hair. This is an X-linked recessive disorder of copper metabolism.
Lysosomal storage disorders usually do not present in the neonatal period with 2 prominent exceptions:
I-cell disease (mucolipidosis II) - coarse features, hepatosplenomegaly. A lysosomal storage disease due to a defect in targeting lysosomal enzymes to the lysosome.
Pompe's disease (type II glycogenosis) - hypertrophic cardiomyopathy, macroglossia.
A lysosomal glycogen storage disorder due to a deficiency in acid maltase (a-glucosidase).
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