Penicillins are the drugs of choice for pediatric infections caused by the following EXCEPT
Rationale:
Penicillins are the drugs of choice for pediatric infections caused by the following EXCEPT L. monocytogenes.
L. monocytogenes causes serious infections like meningitis, especially
The BEST second step in question 9 scenario is to
Rationale:
Using bag-mask ventilation is the BEST second step in question 9 scenario.
Bag-mask ventilation is the most effective and recommended method for delivering rescue breaths in an emergency scenario when trained personnel are present
Drugs that are known to cause fever include
Rationale:
Drugs known to cause fever include allopurinol.
Allopurinol is a recognized cause of drug-induced fever, often part of a hypersensitivity reaction known as allopurinol hypersensitivity syndrome (AHS). This severe adverse drug reaction can manifest with fever, rash, eosinophilia, and organ involvement, making it crucial to monitor patients for these symptoms when initiating or continuing therapy with this medication.
A: chlorpheniramine Chlorpheniramine, an antihistamine, primarily causes drowsiness and anticholinergic effects, not typically inducing fever as a primary or common adverse reaction.
C: diphenhydramine Diphenhydramine, another antihistamine, commonly produces sedation and dry mouth; it is not generally associated with drug-induced fever.
D: acetazolamide Acetazolamide, a carbonic anhydrase inhibitor, can cause metabolic acidosis or paresthesias, but fever is not a characteristic or frequent side effect.
The recommended treatment of HHV-6 infection complicated by seizures is
Rationale:
The recommended treatment of HHV-6 infection complicated by seizures is symptomatic treatment only.
HHV-6 is a neurotropic virus, and seizures, particularly febrile seizures, are a common complication in children. Despite the association, there is currently no specific antiviral therapy proven effective in preventing or treating HHV-6-associated seizures. Therefore, clinical guidelines universally recommend managing the seizures and associated symptoms, such as fever, rather than administering antiviral drugs, which lack demonstrated efficacy in this context.
A: acyclovir Acyclovir primarily targets HSV and VZV, not HHV-6. Its mechanism of action is significantly less effective against HHV-6 replication, rendering it an inappropriate and ineffective choice for managing HHV-6-related complications like seizures.
B: ganciclovir While ganciclovir has some in vitro activity against HHV-6, its clinical efficacy specifically for HHV-6-associated seizures has not been established. Its potential toxicity outweighs any unproven benefit for this particular complication.
C: famciclovir Famciclovir is a prodrug of penciclovir, primarily used for HSV and VZV infections. It exhibits negligible activity against HHV-6, making it entirely unsuitable as a therapeutic agent for HHV-6-induced seizures.
NICUs with a high incidence of invasive candidiasis should consider prophylaxis with fluconazole in infants with a birthweight of
Rationale:
NICUs with a high incidence of invasive candidiasis should consider prophylaxis with fluconazole in infants with a birthweight of <1,000 g.
Fluconazole prophylaxis is recommended for very low birth weight infants, specifically those weighing less than 1,000 grams, in neonatal intensive care units experiencing a high burden of invasive candidiasis. This targeted intervention significantly reduces the incidence of systemic fungal infections, which are associated with high mortality and morbidity in this extremely vulnerable population, optimizing their clinical outcomes.
A: <750 g While extremely premature, guidelines broaden prophylaxis to include all infants weighing up to 1,000 grams, recognizing a wider at-risk population for candidiasis in high-incidence units.
C: <1,500 g Expanding prophylaxis to this weight category is generally not supported by current evidence for routine use, as the risk-benefit profile does not typically warrant it for infants above 1,000 grams.
D: <2,000 g This birthweight threshold is too broad for universal fluconazole prophylaxis recommendations, as infants above 1,000 grams usually exhibit a significantly lower risk of invasive candidiasis in high-incidence NICUs.
The IgM response occurs earlier in the illness, generally peaking at 7-10 days after infection, and usually disappears within a few weeks, but for some infections it can persist for months such as
Rationale:
Hepatitis A is an infection for which the IgM response can persist for months.
Hepatitis A virus infection is a well-documented example where IgM antibodies can remain detectable for several months, often up to 3-6 months, sometimes even longer, after the initial acute phase. This extended persistence of IgM makes it a valuable marker for recent or ongoing infection, distinguishing it from many other viral illnesses where IgM rapidly wanes within weeks. Its prolonged presence significantly aids in diagnostic timing.
A: measles Measles IgM antibodies typically disappear within a few weeks to a couple of months post-infection, rarely persisting for extended periods. Its diagnostic window for IgM is generally shorter compared to infections with prolonged detection.
B: mumps Mumps IgM usually becomes undetectable within weeks to a few months after acute infection. While present initially, its duration is not typically characterized by the prolonged, multi
Complications of campylobacter jejuni can include acute and late onset complications that may present after the acute infection has resolved. Of the following, the MOST common late-onset complication is
Rationale:
Reactive arthritis is the MOST common late-onset complication of Campylobacter jejuni.
Campylobacter jejuni infection is a well-established trigger for reactive arthritis, making it the most frequently observed post-infectious sequela. This sterile inflammatory arthritis typically manifests weeks after the acute diarrheal illness has resolved, affecting peripheral joints. Its strong association with specific HLA-B27 genotypes further underscores its commonality as a late-onset complication following Campylobacter gastroenteritis.
B: immunoglobulin A nephropathy IgA nephropathy is a distinct kidney disease, not commonly linked to Campylobacter jejuni infections as a direct late-onset complication. Its pathophysiology differs significantly from post-enteric arthritides.
C: immune complex glomerulonephritis Immune complex glomerulonephritis can follow certain infections, but it is far less frequently associated with Campylobacter jejuni than reactive arthritis. Other bacterial pathogens more commonly precipitate this renal condition.
D: hemolytic anemia Hemolytic anemia is not a typical late-onset complication of Campylobacter jejuni infection. While some acute infections can rarely cause transient anemia, a persistent hemolytic state is uncharacteristic as a post-infectious sequela.
The initial treatment of choice for localized neuroblastoma is
Rationale:
The initial treatment of choice for localized neuroblastoma is surgical excision.
For localized neuroblastoma, surgical excision represents the primary therapeutic modality. Complete tumor removal offers the best prognosis and often constitutes curative treatment for early-stage disease. This aggressive upfront surgical approach minimizes the need for more intensive adjuvant therapies, significantly improving long-term survival rates and reducing potential treatment-related morbidities in pediatric patients with confined malignancies.
A: radiotherapy Radiotherapy is typically reserved for unresectable tumors, metastatic disease, or situations requiring local control after incomplete resection, not as the primary initial approach for localized neuroblastoma.
C: chemotherapy Chemotherapy is generally employed for high-risk, metastatic, or unresectable tumors, or as an adjuvant therapy, rather than the initial standalone treatment for localized, resectable neuroblastoma.
D: watchful waiting Watchful waiting is inappropriate for localized neuroblastoma, a potentially aggressive malignancy requiring prompt intervention; delaying treatment risks disease progression and complicates eventual management.
Most infants with herpes simplex virus (HSV) infection are normal at birth, and symptoms of infection develop at
Rationale:
Symptoms of herpes simplex virus (HSV) infection in most infants develop at 11 to 15 days of life.
Infants typically present with symptoms of HSV infection within the second week of life, commonly between days 11 and 15. This delayed onset occurs because the virus, often acquired perinatally, requires an incubation period before manifesting clinical signs. Initial normality at birth transitions to symptomatic disease as viral replication progresses, causing systemic or localized effects.
A: 5 to 10 days of life While some rare cases might manifest earlier, the typical incubation period for neonatal HSV generally extends beyond this initial timeframe, making clinical presentation during these days less common.
C: 16 to 20 days of life This period falls slightly outside the most frequently observed window for initial symptom development in infants with HSV. Most cases typically present earlier, by
In multiple gestations, the birth order of twins affects morbidity by increasing the risk of the second-born twin for all the following EXCEPT
Rationale:
Anemia is not an increased risk for the second-born twin in multiple gestations.
The second-born twin does not inherently face a higher risk of anemia specifically due to birth order. While complications like twin-to-twin transfusion syndrome can lead to anemia in one twin, this is a prenatal condition affecting either twin, not a direct consequence of being born second. Birth order primarily impacts immediate delivery-related morbidities.
B: birth trauma The second twin has a greater chance of experiencing birth trauma due to potential changes in uterine tone, prolonged delivery interval, or obstetric maneuvers required for extraction.
C: birth asphyxia Delayed delivery of the second twin can lead to increased risk of placental abruption, umbilical cord compression, or uteroplacental insufficiency, culminating in higher rates of asphyxia.
D: breech position The second twin frequently presents in a non-vertex, often breech, position, increasing the likelihood of complicated delivery requiring intervention or contributing to trauma or asphyxia.
Congenital CMV infection proved when CMV detected within the first
Rationale:
Congenital CMV infection is proved when CMV is detected within the first 3 wks after birth.
Congenital cytomegalovirus (CMV) infection is definitively diagnosed when the virus is identified in an infant's urine, saliva, or blood within the initial three weeks following birth. This specific timeframe distinguishes true congenital infections, acquired in utero, from perinatal or postnatal acquisitions, which typically manifest later. Early detection is crucial for timely intervention and managing potential long-term developmental sequelae associated with intrauterine transmission.
B: 6 wks after birth This timeframe extends beyond the established diagnostic window for congenital CMV, making it less specific for an infection acquired in utero. Detection at six weeks could indicate perinatal acquisition, confusing the origin.
C: 9 wks after birth Identifying CMV at nine weeks postpartum strongly suggests a perinatal or postnatal acquisition rather than a truly congenital one. This extended period would not reliably confirm intrauterine transmission.
D: 12 wks after birth CMV detection at twelve weeks post-delivery would almost certainly represent a perinatal or postnatal infection, not a congenital one. This prolonged interval fails to distinguish prenatal exposure from later environmental acquisition.
Primary pulmonary hypertension of the newborn (PPHN) is characterized by severe hypoxemia, without evidence of parenchymal lung or structural heart disease. Of the following, the congenital heart disease that is initially indistinguishable from PPHN is
Rationale:
The congenital heart disease initially indistinguishable from PPHN is total anomalous venous return.
Total anomalous pulmonary venous return (TAPVR) presents with severe hypoxemia due to desaturated systemic venous blood mixing with pulmonary venous blood before entering the systemic circulation. This results in cyanosis and respiratory distress, mimicking PPHN's severe hypoxemia without obvious structural lung disease on initial assessment. Both conditions involve profound oxygenation failure, making early differentiation challenging before detailed cardiac imaging.
A: aortic stenosis Aortic stenosis primarily causes left ventricular outflow obstruction, leading to signs of heart failure or shock, not typically severe hypoxemia as the primary initial presentation mimicking PPHN.
B: tricuspid atresia Tricuspid atresia involves severe right-sided heart
Which is not true of herpes simplex virus (HSV) infections in neonates?
Rationale:
Most mothers of newborns with perinatal HSV have a history of genital HSV is not true of herpes simplex virus (HSV) infections in neonates.
The statement "Most mothers of newborns with perinatal HSV have a history of genital HSV" is incorrect. A significant proportion of mothers transmitting HSV to their neonates actually lack a prior diagnosis or known history of genital herpes. Many acquire the infection during pregnancy or have asymptomatic shedding, making a documented history uncommon for the majority of these transmitting mothers.
A: Most cases are caused by HSV type 2. HSV-2 typically causes the majority of neonatal infections, reflecting its prevalence in genital herpes. Perinatal transmission predominantly involves this strain, leading to severe outcomes in newborns.
B: Women with primary HSV genital tract infection are more likely to transmit infection to their offspring than women with recurrent HSV infection. Primary maternal infection presents a significantly higher risk of neonatal transmission due to extensive viral shedding and a lack of protective maternal antibodies.
D: Most mothers of newborns with perinatal HSV are asymptomatic at delivery. Maternal HSV shedding often occurs without overt lesions or symptoms at the time of delivery, meaning many transmitting mothers are unaware of their infectious status.
The MOST correct statement consistent with grade 3 intraventricular hemorrhage (IVH) is
Rationale:
Blood noted in the ventricle with ventricular dilation is the MOST correct statement consistent with grade 3 intraventricular hemorrhage (IVH). Grade 3 IVH specifically involves substantial bleeding within the ventricular system, which typically leads to noticeable ventricular enlargement. This degree of hemorrhage signifies a significant volume of blood affecting cerebrospinal fluid dynamics and often causing hydrocephalus, manifesting as ventricular dilation without parenchymal involvement.
A: IVH is confined to the germinal matrix This description aligns with a Grade 1 IVH, where bleeding is restricted to the subependymal germinal matrix. Grade 3 involves significant intraventricular blood, extending well beyond this confined region.
C: blood noted in the ventricle without ventricular enlargement The absence of ventricular enlargement suggests a milder IVH, such as Grade 1 or 2, where the volume of intraventricular blood is insufficient to cause significant dilation. Grade 3 implies substantial ventricular distension.
D: blood in dilated ventricles and in the cerebral cortex contiguous with the ventricle This presentation describes Grade 4 IVH, characterized by intraventricular hemorrhage combined with parenchymal involvement, meaning blood extends into the surrounding brain tissue. Grade 3 specifically lacks parenchymal extension.
S. pneumoniae is the most frequent cause of bacteremia, bacterial pneumonia, otitis media, and bacterial meningitis in children. Children at increased risk of pneumococcal infections include those with the following conditions EXCEPT
Rationale:
Megaloplastic anemia is the condition that does NOT increase a child's risk of pneumococcal infections.
Megaloblastic anemia primarily involves impaired DNA synthesis leading to large, immature red blood cells, often due to folate or B12 deficiency. This condition does not directly compromise the immune system's ability to combat bacterial pathogens like S. pneumoniae. Unlike other immunodeficiency states or anatomical vulnerabilities, megaloblastic anemia lacks a direct pathophysiological link to heightened susceptibility to pneumococcal disease.
B: deficiencies in humoral immunity Humoral immunity, involving antibodies, is crucial for fighting encapsulated bacteria like S. pneumoniae. Its impairment directly hinders the body's ability to recognize and clear these specific pathogens.
C: HIV infection HIV infection progressively devastates the immune system, particularly T-cell function, leading to a profound overall immunodeficiency. This significantly elevates susceptibility to opportunistic infections, including S. pneumoniae.
D: cerebrospinal fluid leak A cerebrospinal fluid leak creates a direct pathway for bacteria, including S. pneumoniae, to access the central nervous system. This anatomical breach bypasses normal protective barriers, drastically increasing meningitis risk.
In the delivery room and after prolonged labor you received a newborn baby with central and peripheral cyanosis, heart rate 90/min, weak cry, arms and legs well flexed, and withdrawal motion. The Apgar score is
Rationale:
The Apgar score is 6.
The infant's score is calculated by summing points across five criteria. Zero points for central and peripheral cyanosis (Appearance), one for a heart
A 9-month-old infant presents with history of early-onset jaundice and growth retardation; on examination there are cataracts, hepatosplenomegaly, and purpuric skin lesions; CBC revealed thrombocytopenia; echo study showed peripheral pulmonary artery stenosis. Of the following, the MOST likely diagnosis is
Rationale:
Congenital rubella is the MOST likely diagnosis.
Congenital rubella syndrome classically presents with cataracts, growth retardation, hepatosplenomegaly, purpuric skin lesions (often termed
Which is not a typical symptom of dengue fever?
Rationale:
Mild interstitial pneumonia is not a typical symptom of dengue fever.
Dengue fever primarily manifests with systemic symptoms like high fever, severe headache, muscle and joint pain, and various rashes. While dengue can affect multiple organs, mild interstitial pneumonia is not recognized as a common or typical clinical feature of the disease. Respiratory complications are rare and usually secondary, not a direct, primary symptom, distinguishing it from the characteristic signs.
A: Headache Headache, particularly retro-orbital pain, is a hallmark symptom of dengue fever, frequently reported by patients experiencing the acute phase of the illness.
B: A transient macular rash for the first 1-2 days of fever This early, often fleeting macular rash is a recognized initial presentation in some dengue cases, preceding the more classic maculopapular eruption.
C: A maculopapular rash after defervescence The characteristic "islands of white in a sea of red" maculopapular rash typically appears around defervescence or during the recovery phase of dengue fever.
Enhanced elimination by alkalinization of urine may be helpful in toxic doses or ingestion of
Rationale:
Enhanced elimination by alkalinization of urine may be helpful in toxic doses or ingestion of phenobarbitone.
Phenobarbitone is a weak acid. Alkalinization of urine (e.g., with sodium bicarbonate) increases the pH, which ionizes the phenobarbitone in the renal tubules. This ionization reduces its reabsorption from the tubules back into the bloodstream, thereby significantly enhancing its renal excretion. This strategy is crucial for accelerating drug removal in cases of phenobarbitone overdose, reducing its systemic toxicity and duration of action.
A: methotrexate Methotrexate elimination benefits from urine alkalinization to prevent renal tubular precipitation, not primarily to ionize the drug for enhanced excretion. Its primary elimination mechanism differs.
B: acetaminophen Acetaminophen elimination is predominantly via hepatic metabolism and glucuronidation. Urine alkalinization offers no significant benefit for enhancing its renal excretion in toxic ingestions.
C: oral hypoglycemic agents Oral hypoglycemic agents, like sulfonylureas, are primarily metabolized hepatically or excreted renally, but their elimination is not significantly augmented by urine alkalinization. This intervention is ineffective for their overdose.
The minimum interval between the 2 doses of MMR is
Rationale:
The minimum interval between the 2 doses of MMR is 4 wk.
A 4-week (or 28-day) minimum interval between MMR doses is crucial for optimal seroconversion and sustained immunity. This duration allows the initial immune response to develop sufficiently while preventing interference with the second dose. Administering the second dose too soon could diminish its effectiveness, ensuring robust protection against measles, mumps, and rubella requires this specific timing.
A: 2 wk A 2-week interval is insufficient for the primary immune response to fully develop, potentially leading to suboptimal antibody production and reduced vaccine efficacy from the second dose.
C: 2 mo While 2 months (8 weeks) is a safe interval, it is not the minimum required. Waiting this long unnecessarily delays the full protective immunity that could be achieved sooner.
D: 6 mo A 6-month interval is significantly longer than necessary for the minimum spacing between MMR doses. Such a prolonged wait leaves individuals vulnerable to infection for an extended period.
In the United States, the MOST common bacterial food-borne cause of diarrhea is
Rationale:
Campylobacter is the MOST common bacterial food-borne cause of diarrhea in the United States.
Campylobacter species, particularly Campylobacter jejuni, are widely recognized as the leading bacterial pathogens responsible for foodborne diarrheal illness in the U.S. Annually, these bacteria cause an estimated 1.5 million illnesses. Contaminated poultry and unpasteurized milk are frequent sources, leading to gastroenteritis characterized by fever, abdominal pain, and watery or bloody diarrhea.
A: Shigella Shigella causes shigellosis, a significant diarrheal disease, but it is less prevalent as a foodborne pathogen compared to Campylobacter in the U.S. It primarily spreads person-to-person or through contaminated water.
C: E. coli 0157:H7 E. coli O157:H7 is a severe foodborne pathogen causing bloody diarrhea and hemolytic uremic syndrome. While dangerous, its incidence is considerably lower than Campylobacter annually, making it not the most common.
D: Listeria monocytogenes Listeria monocytogenes causes listeriosis, a serious foodborne illness. It primarily affects vulnerable populations and rarely causes diarrhea; instead, it typically leads to meningitis or septicemia, distinguishing its primary clinical presentation.
The diagnosis of UTI in infants requires the presence of both pyuria and single pathogenic organism of at least
Rationale:
The diagnosis of UTI in infants requires the presence of both pyuria and a single pathogenic organism of at least 50,000 CFU/mL.
For infants, a urine culture
A 16-year-old female presents with signs and symptoms of appendicitis. Her past medical history is significant only for sexual activity and placement of an IUD 1 year previously. She undergoes an appendectomy, in which her appendix is found to be normal. One month postoperatively, she has local pain and has an irregular, hard mass in her ileocecal area. The most likely diagnosis is
Rationale:
Pelvic actinomycosis is highly suggested by the patient's IUD history and subsequent development of an irregular, hard ileocecal mass following a normal appendectomy. Actinomyces, a slow
All the following regarding assessment and care of infants with pertussis are true EXCEPT
Rationale:
A paroxysm must be witnessed before a decision is made between hospital and home care.
The decision for hospital versus home care for infants with pertussis does not mandate witnessing a par
The MOST common complication of measles infection is
Rationale:
The MOST common complication of measles infection is otitis media.
Otitis media represents the most frequent bacterial complication following measles, particularly in young children. The viral infection compromises the respiratory epithelium, facilitating bacterial superinfection of the middle ear. This secondary bacterial invasion leads to inflammation and fluid accumulation, manifesting as ear pain and fever. Its high incidence significantly contributes to measles-related morbidity.
B: myocarditis Myocarditis, inflammation of the heart muscle, is a rare but severe complication of measles. While serious, its infrequent occurrence places it far below otitis media in terms of overall prevalence.
C: encephalomyelitis Encephalomyelitis, an inflammation of the brain and spinal cord, is a very serious neurological complication. It occurs rarely and carries a high mortality or significant long-term sequelae, but it is not common.
D: interstitial pneumonia Interstitial pneumonia is a recognized pulmonary complication, often severe, especially in immunocompromised individuals. However, its overall incidence across all measles cases is significantly lower than that of secondary bacterial otitis media.
The MOST common solid tumors in children are
Rationale:
CNS tumors are the MOST common solid tumors in children.
Central Nervous System (CNS) tumors, including brain and spinal cord tumors, represent the largest category of solid neoplasms diagnosed in pediatric populations. Their prevalence surpasses other types, making them the leading cause of cancer-related mortality in children. These diverse tumors originate from various neural tissues, presenting unique diagnostic and therapeutic challenges due to their critical locations and complex biology.
A: lymphomas Lymphomas are significant pediatric cancers, but they are hematological malignancies, not solid tumors in the same primary sense as CNS tumors, and less prevalent overall.
B: sarcomas Sarcomas, while common solid tumors originating from connective tissues in children, including osteosarcoma and rhabdomyosarcoma, collectively occur less frequently than CNS tumors.
C: hepatoblastomas Hepatoblastomas are rare malignant liver tumors found primarily in very young children, constituting a very small fraction of all pediatric solid tumor diagnoses.
Sudden onset, short duration seizure that appears on day 1 to 3 of life in a well appearing infant that do not recur may be the result of
Rationale:
Benign familial seizures can cause sudden onset, short duration seizures appearing on day 1 to 3 of life in a well-appearing infant that do not recur.
Benign familial neonatal seizures (BFNS) typically manifest between day 2 and 7 of life, often on day 1-3, in otherwise healthy, well-appearing full-term infants. These seizures are usually brief, self-limiting, and do not recur, aligning perfectly with the description. They are inherited in an autosomal dominant pattern and have an excellent prognosis with normal neurodevelopment. This transient neurological event is characteristic of BFNS.
A: hypoglycemia Hypoglycemia-induced seizures typically present with other signs of metabolic distress and are often
Bulbar conjunctivitis in a child with FUO suggests
Rationale:
Bulbar conjunctivitis in a child with FUO suggests leptospirosis.
Leptospirosis, caused by Leptospira bacteria, is a zoonotic infection often presenting with fever of unknown origin (FUO) and characteristic bulbar conjunctivitis. This conjunctival suffusion, often described as "red eyes without discharge," is a key diagnostic clue, especially when combined with systemic symptoms like myalgia, headache, and potential organ involvement in a child with FUO, guiding appropriate testing and treatment.
B: coxsackievirus infection Coxsackievirus infection typically causes hand-foot-and-mouth disease or herpangina, which are characterized by specific rash or oral lesions rather than isolated bulbar conjunctivitis as a primary, distinguishing feature in FUO cases.
C: tuberculosis Tuberculosis primarily manifests with pulmonary symptoms, lymphadenopathy, or extrapulmonary disease, and while it can cause FUO, bulbar conjunctivitis is not a recognized or typical presenting sign of active mycobacterial infection.
D: infectious mononucleosis Infectious mononucleosis presents with classic triad of fever, pharyngitis, and lymphadenopathy, often accompanied by fatigue or splenomegaly; bulbar conjunctivitis is not a characteristic or common manifestation of Epstein-Barr virus infection.
The MOST common complication of acute severe meningococcal septicemia is
Rationale:
Focal skin infarction is the MOST common complication of acute severe meningococcal septicemia.
Meningococcal septicemia frequently triggers disseminated intravascular coagulation (DIC) and widespread vascular damage. This leads to thrombotic occlusion of small blood vessels, particularly in the skin. The resulting ischemia manifests as purpuric rash, which can rapidly progress to necrotic lesions and focal skin infarction, making it a hallmark and the most prevalent severe dermatological sequela of the disease.
A: arthritis While septic arthritis can occur, it is a less common complication compared to the extensive skin involvement seen in severe meningococcal septicemia, which often presents with purpura fulminans.
C: endocarditis Endocarditis is an infrequent complication of acute meningococcal septicemia, typically associated with chronic or subacute infections rather than the acute, fulminant presentation primarily affecting vascular integrity.
D: pneumonia Meningococcal pneumonia certainly exists, but in the context of septicemia, widespread skin infarction due to vasculitis and DIC is a far more characteristic and prevalent acute complication.
All of the following are true of cat-scratch disease EXCEPT that
Rationale:
Fever ($\geq 38.1^{\circ} \mathrm{C}$) occurs in $90 \%$ of patients is the statement that is NOT true of cat-scratch disease.
Cat-scratch disease typically presents with fever, but its reported incidence is significantly lower than 90%. While many patients