UMEM Educational Pearls - By Rose Chasm

Category: Pediatrics

Title: phenylketonuria (PKU)

Posted: 9/25/2009 by Rose Chasm, MD (Updated: 9/26/2009)
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  • although newborn screening for PKU has been routine throughout North America since the 1960's, it is not routine in undeveloped countries (beware immigrants, foreign visitors)
  • PKU is caused by phenylalanine hydroxylase (PAH) deficiency which catalyzes the conversion of phenylalanine to tyrosine
  • neonates with PKU typically show no physical signs of hyperphenylalaninemia
  • children with untreated PKU have impaired brain development with poor brain growth, seizures, behavior problems, and severe mental retardation
  • affected individuals exude a pungent, musty odor due to elevated phenylalanine levels which also causes skin conditions such as eczema
  • because there is absent tyrosine production with reduced tyrosinase, the hair and skin are very lightly pigmented
  • early diagnosis and management with a low-phenylalanine diet eliminates these complications; and once treated, affected children are healthy and do not require hosopitalizations

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Category: Pediatrics

Title: Pediatric Status Epilepticus

Posted: 8/26/2009 by Rose Chasm, MD (Emailed: 8/27/2009) (Updated: 2/27/2020)
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  • Status epilepticus is defined as either a continuous convulsion or serial convulsions without loss of consciousness that lasts 30 minutes.
  • First line treatment:  benzodiazepine because it is absorbed rapidly into the nervous system; lorazepam (0.05 to 0.1 mg/kg) is preferred over diazepam (0.2 to 0.5 mg/kg) because of its longer half-life in the CNS; rectal administration of the intravenous formulation or the commercially available gel at the same doses may be subsitutued if no IV is attainable.
  • if seizure activity persists beyond 10 - 15 min, a longer acting anticonvulsant such as phenytoin (18 -20 mg/kg), fosphenytoin, or phenobarbital (18 - 20 mg/kg) is administered; they take longer to penetrate the CNS, but have much longer half-lives than the benzodiazepines.  Phenobarbital is given to infants while phenytoin or fosphenytoin is given to older children.
  • Fosphenytoin, a prodrug to phenytoin, increasingly is replacing phenytoin as the drug of choice.  It can be administered at two to three times the rate of phenytoin and is less caustic to skin in teh event of vein extravasation.  It can als be given intramuscularly, while phenytoin can't.

 

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Category: Pediatrics

Title: Swallowed Coins

Posted: 8/1/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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  • peak age of coin ingestion is 1-3 years, 60% being males
  • CXR is recommended, and if in esophagus the flat surface of coin is seen on the AP view with the edge seen on the lateral view
  • if in the stomach, expectant observation (3-4 days) in the absence of abdominal pain and vomiting
  • 20% of coins will lodge in the esoophagus at the level of the cricopharyngeus muscle, aortic arch, and lower esophageal sphincter
  • the change in composition of pennies from cooper to zinc in recent years has increased the potential for mucosal corrosion
  • all coins lodged in the proximal esophagus should be removed endoscoopically as soon as possible
  • coins in the mid- to lower esophagus may be observed for 12-24 hours if asymptomatic, but should undergo endoscopy if the coin fails to pass in that time period

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Category: Pediatrics

Title: Kartagener Syndrome

Posted: 7/25/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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  • triad of chronic sinusitis, bronchiecctasis, and situs inversus
  • recurrent acute otitis media and nasl polyps also common
  • syndrome is due to an ultrastructural abnormality of the cilia in which dynein arms are absent resulting in ciliary dysfunction and mucus stasis and frequent sinopulmonary infections
  • situs inversus is due to the absence of the influence of cilia function on viscera development
  • diagnosed by bronchoscopy for cilia biopsy

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  • results from failure of the upper femoral epiphysis, which allows displacement of the femoral head on the femoral neck
  • onset may be sudden, but more often is gradual
  • pain frequently is referred to the knee, but can also occur in the hip
  • limp and out-toeing are common, with loss of medial hip rotation
  • majority of patients are 7-15 years old, and are aboce the 95th percentile for weight
  • AP or frog-leg lateral xrays of the hip are diagnostic

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  • CNSD, also known as toddler's diarrhea
  • the most common cause of chronic diarrhea in childhood
  • possibly a variant of irritable bowel syndrome, family history of IBS is common
  • children are 6-58 months of age, most commonly 11-24 months old)
  • otherwise in good health with normal weight gain, without signs of malabsorption syndrome or enteric infection
  • morning stool is the most formed, with the stools becoming progressively looser through the day that are malodorous with food particles
  • most often due to dietary factors causing altered gastrointestinal motility such as reduced fat intake or excessive fluid intake, especially sucrose-containing fruit juices
  • treatment is based on modification of the contributing dietary factors

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Category: Pediatrics

Title: Pediatric Nephrotic Syndrome

Posted: 6/21/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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  • Characterized by proteinuria, hypoalbuminemia, edema, and hypercholesterolemia
  • Abnormal Vitals:  tachypnea (due to pulmlonary edema); tachycardia (intravascular depletion); hypertension
  • Abnormal PE:  peripheral edema, ascites, S3 on ausculation
  • UA demonstrates significant proteinuria.
  • TX is uniformly with oral steroids.

Category: Pediatrics

Title: Pediatric Drownings

Posted: 6/8/2009 by Rose Chasm, MD (Updated: 6/9/2009)
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  • Rates are highest for children <5yrs and between 15-24 yrs old.
  • Most of pathology is related to duration of asphyxia from time of submersion until adequate respiration is restored.
  • The brain and heart are most vulnerable to anoxic and ischemic injury.
  • Prognosis for near-drowning depends primarily on the degree of brain anoxia.
  • Prolonged submersion (>25 min); apnea or coma at presentation to ED; and initial arterial pH <7.0 are all poor prognostic indicators.
  • 96% of victims who require <10min of CPR survive with no or only mild neurologic impariment.

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Category: Pediatrics

Title: hemorrhagic desease of the newborn

Posted: 5/15/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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Classic presentation:  breastfeeding failure with umbilical stump and gastrointestinal bleeding by postnatal day 7.  Oozing from circumcision, venipuncture, and heel sticks is also common.  Beware bleeding into the scalp or intracranial space.

Due to essential vitamin K deficiency which exists at birth as the fetus receives little vitamin K from the uteroplacental circulation.  It is responsible for impaired neonatal clotting function (deficiency of factors II, VII, IX, and X).

Prevented by a single intramuscular dose of 1mg vitamin K in the first few hours following delivery.

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Category: Pediatrics

Title: Pediatric Pancyotpenia

Posted: 5/1/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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Pancytopenia manifests as a decrease in the erythroid, myeloid, and megakaryocytic cell lines that appears as a decrease in red blood cells, white blood cells, and platelents on complete blood count analysis. 

  • Indicates bone marrow failure
  • May be due to invasion of marrow by nonneoplastic (such as drugs, chemicals, irradiation, or infections) or neoplastic conditions
  • Clinically manifests as pallor, easy fatigability, and weakness due to anemia; purpura, epistaxis, and bruising due to thrombocytopenia; and increased susceptibility to infection due to leukoopenia.

Pancytopenia is an absolute indication for bone marrow aspiration and biopsy to delineate and treat the cause.

 

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Category: Pediatrics

Title: Scabies

Posted: 4/17/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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  • Scabiess requires sensitization to the organism, Sarcoptes scabiei. 
  • It may take weeks before pruritus develps in a child infested for the first time.  On the next exposure, however, INTENSE itching will occur within 24 hours. 
  • Burrows in the webs of fingers and toes are common.
  • Treatment:  Firstline is permethrin 5% cream on the entire body from the neck down, and wash off after 12 hours.  Alternative is lindane 1% (1oz of lotion or 30g of cream) applied in a thin layer over the entire body from the neck down, and thoroughly washed off after 8 hours OR ivermectin 200ug/kg orally repeated in 2 weeks.
  • Many avoid lindane because of neurotoxicity.  Do not apply it after a bath, or to someone with extensive atopic dermatitis as seizures have been reported.
  • Decontaminate all bedding and cloting.
  • Warn patients that the rash and itching may persist for up to 2 weeks after treatment.

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Category: Pediatrics

Title: Hemolytic-uremic syndrome (HUS)

Keywords: Hemolytic-uremic syndrome (HUS) (PubMed Search)

Posted: 4/3/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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Hemolytic-uremic syndrome (HUS)

  • Characterized by hemolytic anemia (pallor on exam), acute renal failure (oliguria or anuria by history), and thrombocytopenia (petechiae).
  • HUS is one of the most common causes of acute renal failure in children.
  • Two types: diarrhea-associated (shiga toxin+ or D+) which is more common and has a more favorable prognosis, and non diarrhea-associated (atypical or sporadic or D-).
  • Most common age at presentation is during infancy or young childhood.
  • Pediatric HUS is a true medical emergency.
    • Resuscitation with blood products frequently is required, but it is crucial to provide volume carefully because renal function may be severely compromised.
    • Dialysis is required if anuria persists for 12+ hours or for severe hyperkalemia (>6.5mEq/L) Some patients may benefit from plasmapheresis, but full renal recovery is not certain.

Category: Pediatrics

Title: Acute Laryngotracheobronchitis (Croup)

Keywords: Acute Laryngotracheobronchitis, Croup (PubMed Search)

Posted: 3/25/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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Parainfluenza viruses (types 1, 2, 3) account for more than 65% of all cases. The different serotypes have seasonal patterns, with type 1 and 2 occuring in the autumn and being the most common pathogens associated with croup while type 3 is more frequent in the spring and summer and is associated with pneumonia and bronchiolitis.

Infections are rarely associated with high fever and usually last 4 to 5 days. There are no distinctive laboratory abnormalities, and diagnosis is generally made clinically.  Chest and neck xray may demonstrate a “steeple sign” from narrowing of the subglottic region.  Viral cultures and immunofluorescent rapid antigen identification can be obtained from respiratory secretions.  Specific antiviral therapy is not available. Aerosolized epinephrine can be given to severely affected, hospitalized patients to decrease airway obstruction.  Parental (>0.3mg/kg) and oral ((0.15mg/kg) dexamethasone have been demonstrated to lessen the severity and duration of symptoms and hospitalization in patients with moderate to severe croup.  
 

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Rocky Mountain spotted fever (RMSF)


Systemic small vessel vasculitis caused by R rickettsii which is transmitted by a tick bite.

 

Clinical features: fever, headache, myalgia, nausea, vomiting, and characteristic rash. Rash usually appears before the sixth day of the illness initially on the wrists and ankles, and spreads to the trunk within hours.  Initially. It is erythematous and macular, later becoming petechial.

Laboratory findings: thrombocytopenia, anemia, and hyponatremia.

Complications: meningitis, multiorgan involvement, DIC, shock, and death. 

Treatment: doxcycycline (even despite the risk of dental staining in children younger than 8 years old)

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Category: Pediatrics

Title: Septic / Pyogenic Arthritis

Posted: 2/19/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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  • An acute bacterial infection of a joint.
  • Peak incidence in children is younger than 2 years of age.
  • Risk factors:
    • history of trauma
    • preceding URI
    • immunodeficiency
    • hemoglobinopathy
    • Diabetes.
  • Age is the most important determinant of cause.
    • In all age groups, S aureus is the primary organism accounting for more than 50% of cases.
    • Among neonates, enteric gram-negative organisms and group B Streptococcus are the most frequent causes.
    • Group A Streptococcus, S pneumoniae, and K kingae are common causes in children younger than 5 years old.
  • Blood culture, joint fluid aspiration and analysis, gram stain, and culture of fluid is recommended.
  • In pyogenic arthritis, the joint fluid is usually cloudy and has a leukocyte count of at least 50 x 10000/mcL, with a predominance of polymorphonuclear cells, low glucose concentrations, and high protein values.
  • Treatment involves a combination of parenteral antibiotics, surgical drainage, and decompression of the affected joint.
  • All children who have pyogenic arthritis of the hip or shoulder require prompt open surgical drainage and irrigation to prevent permanent joint damage as the increased intra-articular pressure can compromise blood flow resulting in avascular necrosis of the femoral or humeral head and predisposing the patient to dislocations.
  • Open surgical drainage of other joints usually is not required.

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Category: Pediatrics

Title: Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM)

Keywords: Epstien Barr Virus, Mononucleosis (PubMed Search)

Posted: 2/6/2009 by Rose Chasm, MD (Updated: 2/27/2020)
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Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) 

Most commonly presenting clinical findings: fever, fatigue, exudative pharyngitis, lymphadenopathy, and hepatosplenomegaly. 

Self-limited illness that lasts an average of 2 - 3 weeks. 

Treatment is primarily supportive.  Use of ampicillin, amoxicillin, or penicillin during the acute phase not indicated and may result in the development of a morbilliform rash, which studies have suggested may occur in more than 50% of the cases.  Antiviral therapy is not recommended. Splenic rupture occurs in about 1 - 2:1000 cases.  Therefore, avoidance of activities that increase the risk for injury is recommended until splenomegaly has resolved. 

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Category: Pediatrics

Title: Tinea Capitis

Posted: 3/9/2013 by Rose Chasm, MD (Emailed: 2/27/2020) (Updated: 2/27/2020)
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  • Tinea capitis (ringworm of the scalp) is caused by dermatophytic fungi
  • Trichophyton tonsurans is the most common species in the US, and does NOT flouresce under Wood's lamp
  • Griseofulvin (20-25mg/kg/ day orally) is the standard first-line therapy in children older than 2 years, and has a good safety profile
  • Both tablet and suspension formulations are available, and it should be taken with food that are high in fat to increase drug concentrations
  • NO laboratory assessment of hepatic enzymes is required during the 8-week therapy course in children who have no history or clinical examination findings concerning for liver disease.
  • Topical antifungal agents are ineffective because they do not penetrate sufficiently into the hair shaft.

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