Local Bugs & Drugs
Traveler Bugs & Drugs
Complement fishing
FISH-ing and microarray-ing, etc.
Potpourri
100
What is the most common organism to cause infection in cat bites?
Pasturella. Next most common cause of infection: Staph aureus. Generally all cat bites are treated because of cats' puncturing teeth. Drug of choice: Amoxicillin-clavulanate.
100
A 2-year-old child from rural Chad (Africa) presents with: -fever -paralysis -- began in the proximal muscles of the thigh and progressively has involved more distal muscle groups Diagnosis?
Polio Africa still sees many cases, and Chad had among the highest incidence. This can be differentiated from Guillan-Barre, where the paralysis tends to begin more distally then spread proximally.
100
A 5-year-old presents with meningococcal bacteremia. What lab test should you order (to screen for the most likely immune deficiency associated with this infection)?
CH50 This is the screen to evaluate for a complement deficiency. Specifically, patients with terminal complement deficiency are at increased risk for developing meningococcemia. If the CH50 screen is abnormal, then you would order specific complement levels.
100
A patient has: -Cleft palate -Thymus agenesis (or hypoplasia) -Parathyroid agenesis (or hypoplasia) -Hypoplasia of the auricle and external auditory canal -Cardiac defects: TOF, IAA, VSD, or truncus arteriosus -Short stature -Behavioral problems What diagnostic genetic test would you send?
FISH for 22q11.2 deletion
100
As a single factor, what is the most common cause of strokes in children?
Sickle cell disease (namely genotype SS). Sickle cell disease is responsible for nearly 10% of pediatric strokes.
200
A 2-day-old girl who attends day care presents with: -fever -emesis -bloody diarrhea -(new) tonic-clonic seizure -leukocytosis, with significant bandemia -rectal prolapse What is the most likely etiology?
Shigella. Children 1-4 years of age have the highest incidence. Bloody diarrhea is common and a seizure can commonly occur. Rectal prolapse occurs in 5-8%. Bandemia is very common.
200
A 5-year-old boy from rural Arkansas presents with: -fever to 102 F -R inguinal swollen lymph node What is the most likely diagnosis?
Tularemia On the boards, if you see a child from Arkansas (or Missouri or Oklahoma) and they have lymphadenitis+fever, go for Francisella tularensis. Treat with gentamycin or doxycycline if they are not that ill (but increased risk of relapse)
200
You must answer both questions to get full credit: (1) An 8-year-old boy presents with: -h/o documented strep pharyngitis 10 days ago (treated with IM penicillin) -today, edema and cola-colored urine What do you expect his C3 level to be? (high, low, normal) (2) If the patient had URI symptoms currently, and no h/o strep infection, what would you expect his C3 level to be?
(1) Low (2) Normal (1) The story was most consistent with post-strep glomerulonephritis. The C3 will be low, and remain low for 6-12 weeks. (2) This is more consistent with IgA nephropathy, where the hematuria occurs concurrently with the infection. The C3 will be normal.
200
An infant presents with the following: -pancytopenia -hypoplastic thumb and radius -hyperpigmentation -abnormal faces What is the most likely diagnosis?
Fanconi Anemia Autosomal recessive Note: The aplastic anemia may not show up until 8-9 years of age.
200
A 17-year-old presents to your ED with severe eye pain. Her fundoscopic exam is concerning for optic neuritis. You manage to get her a stat brain MRI, which is also consistent with optic neuritis and also shows some scattered areas of demyelination. What CSF study do you want to send (in addition to the standard studies)?
Oligoclonal bands (due to concern about multiple sclerosis)
300
A child with cyanotic heart disease presents with new onset headache and seizure. MRI shows a brain abscess. What is the likely organism?
S. aureus Children with cyanotic heart disease are at increased risk of brain abscesses due to S. aureus.
300
Amphotericin B causes renal losses of what 2 electrolytes?
Potassium and Magnesium Amphotericin B causes hypokalemia, hypomagnesemia, and RTA. It is important to monitor electrolytes during amphotericin B therapy.
300
A Caucasian child has early-onset systemic lupus erythematosus (SLE). What immune deficiency should you look for?
C2 deficiency C2 deficiency is the most common complement deficiency in North American Caucasians and results in increased risk of SLE.
300
An infant has aniridia and hypospadias. What should this patient be screened for the coming months/years?
Wilms tumor WAGR Syndrome = -Wilms tumor -Aniridia -GU malformation -Mental Retardation Wilms tumor occurs in up to 50% of patients, usually by 3 years of age. WAGR syndrome results from an 11p13 deletion. These patients are also at increased risk for gonadoblastoma.
300
A 10-year-old boy presents with severe back pain that radiates to the front. This is then followed by rapidly progressive paraparesis, loss of sphincter tone, and loss of pain and temperature sensation below the level of T7. What is the most likely diagnosis?
Transverse myelitis Transverse myelitis is segmental spinal cord disease with both motor and sensory abnormalities at and below the level of the lesion. Most lesions occur at the thoracic cord level. MRI may show intramedullary signal change.
400
What is the treatment of choice for group B streptococcus infection?
Penicillin G (or ampicillin) and gentamicin Penicillin G and gentamicin are started initially, with penicillin G continued for 10 days for pneumonia and sepsis, and 14 days minimum for meningitis.
400
A patient in the summertime from rural Connecticut presents with: -fever -HA -leukopenia, thrombocytopenia, anemia -elevated AST and ALT What is the most likely diagnosis? Bonus: What would the most likely diagnosis be if the patient were from Arkansas/Missouri/Oklahoma instead?
Anaplasmosis It is a tick-borne disease due to Anaplasma and predominates in the NE, Midwest, and California. Classically it presents with pancytopenia and fever. A similar disease occurs in Arkansas, Missouri, and Oklahoma due to Ehrlichia.
400
A 10y/o M has had URI symptoms x 2 days, then today developed cola-colored urine. He has a mild sore throat without fever. Family history is notable for an uncle on hemodialysis. C3: 128 (normal 80-200) C4: 27 (normal 16-40) The study most likely to result in a diagnosis is: A) ASLO B) Creatine phosphokinase level C) Hearing screen D) IgA level E) Non-contrast CT of the abdomen
C) Hearing screen (Evaluation for Alport syndrome) The young boy in the vignette has normocomplementemic nephritis and a synpharyngitic syndrome. Ddx includes IgA GN, MPGN, and Alport syndrome. A genetic syndrome is suggested in light of the uncle on hemodialysis. Alport syndrome is associated with b/l high frequency hearing loss. ASLO may be elevated if a streptococcal infection is expected, but the clinical scenario is inconsistent with poststreptococcal glomerulonephritis. A creatine phosphokinase (CPK) level is a useful test when screening for muscle breakdown (rhabdomyolysis) and myoglobinuria. An immunoglobulin A level may be elevated in approximately 15% of children with IgA GN, but because of its low sensitivity and specificity, it has no clinical utility in the diagnosis of IgA GN. An abdominal noncontrast computed tomography (CT) scan is typically a second-line test in the evaluation of urolithiasis if renal and bladder ultrasonography are nondiagnostic; noncontrast CT has no role in the evaluation of a patient with nephritis.
400
An adopted child is brought to your clinic for the first time. She has a white forelock. Remembering your Boards studying, you think of a syndrome involving white forelocks, and decide to evaluate the patient for some other problems. What problems might this patient have? (Name at least 2 for credit. Cosmetic issues don't count here.)
The patient may have Waardenburg syndrome, which is autosomal dominant. It is associated with: -Cochlear deafness (of varying severity) -Cleft lip -Hirschprung disease and of lesser significance: -Premature graying -Iris heterochromia (different colored eyes) -Partial albinism
400
A neonate presents with severe dehydration. Prenatal history notable for polyhydramnios. The infant has hyperaldosteronism, with increased renin secretion, but no hypertension. There is also increased calcium excretion in the urine. What is the most likely diagnosis?
Bartter syndrome Bartter syndrome is associated with hyperaldosteronism and increased renin secretion, but HTN is NOT present.
500
A 17-year-old works in a pet store cleaning fish tanks. He has had skin ulcerations on his R arm for weeks, unresponsive to cephalexin (Keflex). His PMD prescribed doxycycline for presumed MRSA, also without improvement. What is the most likely organism causing his persistent skin ulcerations? Bonus: Treatment?
Mycobacterium marinum Aka the "fish tank bacillus". It causes non-healing skin ulcerations. Often the lesions are along lymphatic channels. Treatment: -Ethambutol + rifampin -Clarithromycin + rifampin
500
A 14-year-old boy from Hawaii presents with the following: -hx of swimming in fresh-water lagoons -fever -myalgias -HA -jaundice Labs: -hyperbilirubinemia -mildly elevated AST and ALT -creatinine 1.9 Most likely diagnosis?
Leptospirosis This is a spirochetal disease transferred by contact with contaminated water or infected animals. Rat and dog urine are the most common vectors. Hawaii has the most cases in the US. This is a disease that is biphasic: Initial febrile illness --> 7 days later, hepatic and renal insufficiency. Diagnose with urine studies after 4-7 days of illness.
500
Name the syndrome: -Maternal breast cancer -Sarcoma in children -Adrenocortical carcinoma -Germline mutations in the p53 gene -CNS tumors: gliomas, ependymomas, choroid plexus carcinomas
Li-Fraumeni syndrome A familial cancer syndrome associated with an increased risk of all types of cancer
500
A 9-month-old presents with: -pallor -irritability -growth retardation -hepatosplenomegaly -jaundice -"chipmunk" facies What's the most likely diagnosis?
beta-thalassemia major This occurs because there is essentially no beta-globin production. Expansion of the bone marrow space in the facial bones leads to the characteristic "chipmunk" facies.
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