Infectious Diseases
A Caucasian adolescent boy presents with hyperpigmented, scaly lesions on his chest and back that worsen when he plays football in the hot sun.
What is the likely diagnosis?
Tinea versicolor
Aka pityriasis versicolor. This is due to Malessezia spp infection, most commonly Malessezia furfur. Lesions can be hypopigmented or hyperpigmented scales. "Spaghetti and meatballs" appearance on skin scrapings. Treat with topical selenium sulfide or topical azole; can use oral medications (fluconazole or itraconazole) if severe or persistent despite first line treatments.
When should infants and toddlers be switched from a rear-facing car safety to a forward-facing car safety seat?
After having reached the highest weight or height allowed by the seat's manufacturer
When should inguinal hernias be repaired?
On diagnosis
Strangulated hernias are a surgical emergency
What type of brain tumor is benign, but because of its invasive growth, commonly impinges on many structures (e.g. optic chiasm, carotid arteries)?
Craniopharyngioma
More than 50% of children with craniopharyngioma have visual changes due to optic involvement. Because it can also involve the pituitary, watch out for growth failure, short stature, and polydipsia
A 6 month old infant presents with tachycardia and respiratory distress. An ECG is done and shows a narrow complex rhythm with a rate of 240 bpm.
What maneuver can be done to slow the ventricular rate and potentially return the child to normal sinus rhythm?
Vagal maneuver, e.g. diving seal reflex (place an ice bag on their face for 10-20 seconds)
The use of ointment in a newborn's eye is useful for preventing which infection(s): gonorrhea, Chlamydia, or both?
Gonorrhea
Erythromycin ointment does not prevent chlamydia trachomatis infection
What are the first teeth to typically emerge?
Mandibular central incisors
General progression: Mandibular central incisors -> maxillary central incisors -> maxillary lateral incisors -> mandibular lower lateral incisors
Which type of renal tubular acidosis is associated with high serum potassium?
Type 4 RTA (hypoaldosteronism)
What major side effect do you worry about with the use of doxorubicin?
Cardiomyopathy
A 6 year old boy presents with a continuous murmur with the following qualities: low-pitched, absent when supine; turning the head or Valsalva maneuver or compression of the jugular vein make the murmur go away.
What is the most likely murmur?
Venous hum
This is due to blood draining down collapsing jugular veins into the larger intrathoracic veins. The high velocity makes the vein walls flutter, resulting in the murmur. When the neck veins distend and there is no pressure gradient between the 2 areas, then the murmur goes away.
A 17 yo boy with a history of current IV drug use (heroin) and multiple sexual partners presents with: fever, lymphadenopathy, pharyngitis, erythematous maculopapular rash on the face, trunk and extremities (including palms & soles), ulcers in his mouth and on his genitals, & myalgias and arthralgias. Rapid mono, strep, and RPR are negative.
What is the most likely diagnosis?
Acute HIV syndrome
Typically occurs 2-4 weeks after the initial infection and lasts 1-2 weeks. Diagnose HIV acutely with HIV antibody/p24 screen. If positive, send for HIV RNA PCR (viral load)
What is the cut-off age for giving DTaP?
< 7 years old
Do not give to kids who are 7 or older. Tdap is recommended at 11-12 years old, followed by a Td booster every 10 years.
A 9 yo boy presents with edema and dark, coco-cola colored urine. He has a documented history of strep throat from 10 days ago, treated with IM penicillin.
What do you expect his complement levels (C3 and C4) to be?
C3: Low; C4: Typically normal (to mildly low)
The key lab finding in acute post-strep glomerulonephritis is a low C3 level, which will remain low for 2-12 weeks. Note: membranoproliferative glomerulonephritis is also associated with reduced C3 that persists beyond 12 weeks.
What is the most likely diagnosis?
Neuroblastoma
Opsomyoclonus (myoclonic jerking + random eye movements) in association with ataxia is an uncommon presentation for neuroblastoma (~5%). The most common presentation is a nontender abdominal mass.
A child presents with mitral valve prolapse with a midsystolic click and a murmur heard best at the apex.
What antibiotic prophylaxis does he require before his dental cleaning?
None
Only children with the following should receive antibiotic prophylaxis: prosthetic heart valves, previous hx of endocarditis, unrepaired cyanotic heart disease, completely repaired heart disease with prosthetic material or device for 6 months after the repair, repaired congenital heart disease with a residual lesion, or cardiac transplant recipients who develop a valvulopathy.
"Prosthetic component, prior infection, unrepaired abnormal heart, or damaged transplant"
A patient in the summertime from the rural northeast presents with: fever, headache, leukopenia, thrombocytopenia, anemia, and elevated transaminases.
What is the most likely diagnosis?
Anaplasmosis
Anaplasmosis predominates in the NE and Midwest. Classically presents with pancytopenia and fever. Erlichiosis is a similar disease but occurs in a different location (Arkansas, Missouri, Oklahoma).
Varicella and MMR vaccines are contraindicated in patients receiving what dose and course length of systemic corticosteroids?
>/= 2 mg/kg/day (or 20mg/day if weight is > 10kg) for 2 weeks or longer
Must wait at least 1 month between discontinuation of high dose steroids and immunization with MMR or Varicella
What are the most common sites for thromboses in a child with nephrotic syndrome?
Renal vein and sagittal sinus
A child presents with nausea, vomiting, abdominal pain with a mass in the right lower quadrant, and fever. Imaging shows a mass in the ileocecal junction.
What is the most likely diagnosis?
Burkitt lymphoma
Originates from mature B-cells in Peyer patches within the GI tract. Jaw involvement is not as common in the U.S. It is the fastest growing malignant tumor and can result in life-threatening tumor lysis syndrome.
What syndrome is associated with complete interruption of the aortic arch?
DiGeorge syndrome (22q11.2 deletion)
Remember this syndrome has malformations in the development of the pharyngeal arches that ultimately form structures in the mediastinum (aortic arch and cardiac outflow track), neck (thyroid, parathyroid, thymus), and head (ear, midface).
A mother develops chickenpox in the perinatal period.
What time frame determines which newborns should be given varicella immunoglobin?
When mom has lesions 5 days before delivery to 2 days after delivery.
Very important to remember! These infants are at high risk for severe varicella primary infection which has a high case fatality rate! In this time, the newborn is exposed to the virus but have no protective antibodies from mom. Remember: distinguish this from a reactivation of varicella (i.e. herpes zoster, or shingles) -- mom would have protective antibodies in this case which would protect the infant.
A 10 month old and a 3 year old present for evaluation 24 hours after an outbreak of measles was identified. The children were exposed. The 9 month old has not received an MMR vaccine and the 3 year old has received 1 dose.
Is postexposure prophylaxis with MMR vaccine indicated in neither, one, or both of the children?
Both
During an outbreak, measles vaccine given to susceptible individuals within 72 hours of exposure provides protection or at least disease modification. MMR vaccine may be given to infants between 6 months through 11 months during an outbreak. However, seroconversion is significantly lower when this happens in infants < 12 months of age so a MMR vaccine given BEFORE 12 months of age will NOT count toward their required 2-dose series.
What additional vaccine(s) should a child with minimal change nephrotic syndrome receive?
PPSV23
For children with all types of nephrotic syndrome, both pneumococcal vaccines are recommended. The child should receive all recommended PCV-13 vaccines and add PPSV23 in addition.
A child presents with an orbital chloroma and hepatosplenomegaly.
What is the most likely diagnosis?
Acute Myeloid Leukemia
An orbital or epidural chloroma (localized mass of leukemic cells) may be the first clue to AML. Hepatosplenomegaly can sometimes occur, but anemia and thrombocytopenia are almost always present.
A high school football player dies while playing in a game. Hypertrophic cardiomyopathy is ruled out as a cause.
What is the next most likely cause of sudden death in a high school athlete?
Anomalous origin of the left coronary artery from the aorta
This occurs when the left (typically) or the right coronary artery come off the opposite coronary cusp and then passes through the space between the aorta and pulmonary artery. During exercise when the great arteries dilate, the coronary artery can get squished and cut off its circulation, resulting in syncope and sudden death.