Review – Kaplan Pediatrics: Infectious Disease

MENINGITIS

A 6-year-old presents to the physician with the chief complaint of headache, vomiting, neck stiffness, and photophobia. Physical examination reveals an ill-appearing child unable to flex his neck without eliciting pain. Kernig and Brudzincki signs are positive.

 

 

 

Acute Bacterial (Older Than a Neonate)

• First 2 months of life (and some into month 3) represent maternal vaginal flora— group B Streptococcus, coli, Listeria
• Age 2 months to 12 years— pneumoniae (peaks in first 2 years), N. meningitidis (sporadic or in epidemics; direct contact from a daycare center or a colonized adult family member; increased in college freshmen living in dorms), and HiB (now uncommon due to many years of immunization)
• Pathology—meningeal inflammation and exudate
  • Most from hematogenous spread, initially from bacterial colonization of naso- pharynx, and a prior or current viral infection may enhance pathogenicity
  • Rarely from an infection at a contiguous site (sinusitis, otitis media [OM], mas- toiditis, orbital cellulitis)
• Clinical presentation
  • Several days with fever, lethargy, irritability, anorexia, nausea, vomiting
  • Then meningeal irritation (photophobia, neck and back pain, and rigidity)
    • Kernig sign: flexing of the hip 90 degrees and subsequent pain with leg exten- sion (inconsistent)
    • Brudzinski sign: involuntary flexing of knees and hips after passive flexing of the neck while supine (better test)
  • Increased ICP suggested by headache, emesis, bulging anterior fontanelles, ocu- lomotor or abducens palsies, hypertension with bradycardia, apnea, decorticate or decerebrate posturing, stupor, coma
• Diagnosis—need lumbar puncture (LP) and blood culture in all (90% have a posi- tive blood culture)

–     Contraindications to immediate LP

• Evidence of increased ICP
• Severe cardiopulmonary problems requiring resuscitation

 

 

 

 

 

 

 

 

 

 

Note

Infants may not have positive Kernig or Brudzinski sign

in meningitis but will have bulging fontanelles on physical examination.

 

 

• Infection of skin over site
• Do not delay antibiotics for the CT

 

Table 22-1. CSF Findings in Various Types of Meningitis

 

	Bacterial	Partially Treated	Granulomatous (TB)	Aseptic (Viral)
Cells/mL	200–5,000	200–5,000	100–500	100–700
Cytology	Polymorphonuclear neutrophil	Mostly polymorphonuclear neutrophil	Lymphocytes	Mostly lymphocytes
Glucose†	Low	Low	Low	Normal
Protein	High	High	High	Normal to slightly high
Gram stain	Positive	Variable	Negative	Negative
Culture	Positive	Variable	Positive	Negative
CIE or LA	Positive	Positive	Negative	Negative
Pressure	High	High	High	Normal

Definition of Abbreviations: CIE, counterimmunoelectrophoresis; LA, latex agglutination

†CSF glucose concentration should be considered in relation to blood glucose concentration; normally CSF glucose is 50–70% of blood glucose.

 

 

 

• Treatment
  • Initial empiric treatment (age 2 months to 18 years)—vancomycin plus either cefotaxime or ceftriaxone
  • Specific treatment after identification of organism (if sensitive): best drug based on sensitivity and length of diagnosis per organism
  • Data support the use of IV dexamethasone added to initial treatment of meningitis due to Decreased incidence of fever, elevated CSF protein, and 8th cranial nerve damage.
• Complications
  • Increased ICP with herniation and seizures
  • Subdural effusion, especially in infants with HiB, can cause seizures, persistent fever; drain if
  • Cranial nerve palsies, stroke, thrombosis of dural venous sinuses
  • Most common sequelae is hearing loss (especially with pneumococcus)
  • Less common: mental retardation, developmental delay, visual impairment
• Prevention
  • Chemoprophylaxis with rifampin for meningitidis and HiB, but not for

S. pneumoniae

• All close contacts regardless of age or immune status

 

 

Acute Meningococcemia

• Initially may mimic a viral disease (nonspecific)
• Any organ can be affected by vasculitis and thromboembolic
• Characteristic meningococcal rash (black central arch and surrounding ring or erythema) often seen before more serious signs develop
• If fulminant—rapid progression: septic shock, disseminated intravascular coagu- lation, acidosis, adrenal hemorrhage, renal and heart failure
• Petechiae and purpura ± meningitis = purpura fulminans (DIC)
• Need high dose IV penicillin ASAP
• Chemoprophylaxis for close quarters (dorms, army barracks)

 

 

Viral (Aseptic) Meningitis

• Affects meninges and brain tissue variably; most are self-limited; person-to-person contact in summer and fall; most are enteroviruses
  • Arbovirus = arthropod-borne viruses; vectors are mosquitoes and ticks after biting infected birds or small animals; spreads to humans and other vertebrates
• Rural exposure more common
  • Herpes simplex: focal; progresses to coma and death without treatment
• Varicella zoster: most common presentation is cerebellar ataxia and acute
  • Cytomegalovirus: in immunocompromised, disseminated disease; or congenital infection but not in immunocompetent host
  • Epstein-Barr virus (EBV), mumps: mild but with 8th-nerve damage
• Clinical

–     Headache and hyperesthesia in older children

• Irritability and lethargy in infants
• Fever, nausea, vomiting, photophobia, and neck, back, and leg pain
• Exanthems, especially echovirus and coxsackie, varicella, measles, and rubella

• Complications
  • Guillain-Barré syndrome, transverse myelitis, hemiplegia, cerebellar ataxia
  • Most completely resolve without problems except for the neonate with HSV (severe sequelae)
• Diagnosis

–  PCR of CSF is the best test.

• Viral culture
• Treatment—supportive, except acyclovir indicated for herpes simplex virus (HSV)

Note

Anything that suggests temporal lobe involvement (i.e., focal seizures, CT scan, MRI, and EEG findings localized to the temporal lobe) is highly suspicious for herpes simplex virus.

 

Note

• Encephalitis = meningitis + mental status changes
• Consider drug ingestion in differential diagnosis

 

 

 

Note

Pertussis

Early treatment may alter the course of disease. Treatment decreases communicability.

PERTUSSIS

A 10-month-old child who is delayed in immunizations presents with a paroxysmal cough. The patient appears ill and continuously coughs throughout the examination. The patient has facial petechiae and conjunctival hemorrhages. In addition, the patient has post-tussive emesis.

 

• Cause—Bordetella pertussis
  • Endemic; very contagious; aerosol droplets
• Neither natural disease nor vaccination provides complete or lifelong immunity;

wanes after age 8–15 years

• Subclinical reinfection

–     Coughing adolescents and adults are major reservoirs.

• Clinical presentation of whooping cough
  • Catarrhal phase (2 weeks)—coldlike symptoms (rhinorrhea, conjunctival injec- tion, cough)
  • Paroxysmal phase (2–5 weeks)—increasing to severe coughing paroxysms, inspi- ratory “whoop” and facial petechiae; post-tussive emesis
  • Convalescent phase ≥ 2 weeks of gradual resolution of cough
• Diagnosis

–     History may reveal incomplete immunizations

• Gold standard is PCR of nasopharyngeal aspirate 2–4 weeks after onset of cough, or a culture

• Treatment

–  See immunization chapter

• Supportive care
• Always treat if suspected or confirmed: erythromycin for 14 days (other macro- lides with similar results) only decreases infectious period of patient; it may shorten the course of illness; also treat all household members and any close contacts

 

 

Bartonella (Cat-Scratch Disease)

A 6-year-old presents with a swollen 3´5-cm tender, erythematous, anterior cervical neck node. He denies a history of fever, weight loss, chills, night sweats, or sore throat. The patient’s pets include a kitten, a turtle, and goldfish.

 

• Etiologic agent—Bartonella henselae

–     Most common cause of lymphadenitis lasting >3 weeks

• Cutaneous inoculation (arthropod borne by cat flea); kittens transmit better than cats
• Incubation period 3–30 days
• Clinical presentation
  • One or more 3- to 5-mm red to white papules along the linear scratch

plus hallmark: chronic regional lymphadenitis

 

 

 

• Other nonspecific findings: fever, malaise, headache, anorexia
• Less common: abdominal pain, weight loss, hepatosplenomegaly, osteolytic lesion

– Atypical presentation: Parinaud oculoglandular syndrome

• Diagnosis

–     Clinical with history of scratch from cat

• Tissue: PCR and Warthin-Starry stain (shows gram-negative bacilli)
• Serology: variable immunoglobulin IgG and IgM response (not good test)

• Treatment—Antibiotics not used as there is a discordance between in vitro and in vivo activity (use only for severe hospitalized cases) (usually self-limiting and resolves in 2–4 months); aspiration of large and painful lesions

 

 

MYCOBACTERIA

 

Tuberculosis

A 10-year-old child is referred by the school nurse because of a positive tuberculin skin test. The patient has been well, without any associated complaints.

 

•      M. tuberculosis

• High-risk reservoirs—recent immigrants, low SES, HIV, elderly
• Primary complex—affects the lung with local infection with hilar adenopathy
• Latent infection—reactive TB skin test and absence of clinical or radiographic findings
• Diagnosis
  • Skin testing
    • Delayed hypersensitivity—Mantoux (PPD) test

} (+) most often 4–8 weeks after inhalation

• Positive reaction (5, 10, 15 mm), depending on risk factors (see margin note)

• Best—if can get sputum
  • 3 consecutive early a._m. gastric aspirates (still only 50%, even with PCR)
  • A negative culture never excludes the
• Clinical Presentation
  • Primary TB usually asymptomatic in children; healthy host will wall off the organism; occasionally, low-grade fever, mild cough, malaise which resolve in 1 week
  • Infants more likely to have signs and symptoms
  • Reactivation rare, (esp. if acquired <2 years of age) occurs during adolescence
  • Small number with extrapulmonary presentation; symptoms depend on location
• Presentation
  • Primary pulmonary disease
    • Localized nonspecific infiltrate
    • Large adenopathy compared to infiltrate

 

 

Note

Parinaud oculoglandular syndrome consists of:

• unilateral conjunctivitis
• preauricular lymphadenopathy
• cervical lymphadenopathy
• occurs after rubbing the eye after touching a pet

 

Note

Mantoux Test Reactions

• A reaction of >5 mm is positive in those who have been exposed to TB or are
• >10 mm of induration is positive in high-risk
• For low-risk persons, >15 mm is
• Previous vaccination with bacilli Calmette-Guérin (BCG) may cause a false- positive
• Patients who are immunocompromised, are malnourished, or received live-virus vaccines may have a false-negative

 

 

} Compression → atelectasis and hyperinflation

} Most resolve completely

• Extrapulmonary
  • Erosion into blood or lymph = miliary
    • Lungs
    • Spleen
    • Liver
    • Bone and joints—Pott disease (destruction of vertebral bodies leading to kyphosis)
    • TB meningitis—mostly affects brainstem

} Cranial nerve III, VI, VII palsies and communicating hydrocephalus

• If reactivation—fever, anorexia, malaise, weight loss, night sweats, productive cough, hemoptysis, chest pain

• Treatment
  • Latent TB
    • INH × 9 months
  • Primary pulmonary disease
    • INH + rifampin × 6 months

} Plus pyrazinamide in first 2 months

• Increased community resistance
  • Add streptomycin, ethambutol or ethionamide
• In some cases of meningitis, studies have shown decreased morbidity and mor- tality when corticosteroids added to Use adjunctively in patients with severe miliary disease and pericardial or pleural effusions.

 

Bacille Calmette-Guérin (BCG) Vaccination in the United States

• Not routine—variable efficacy, time-limited efficacy
• Only used in the following situations:
  • High-risk with close or long-term exposures

– Continuous exposure to resistance strains

• Contraindicated in those with primary or secondary immune deficiencies

 

Perinatal Tuberculosis

• If mother has (+) PPD → obtain chest x-ray
• If chest x-ray (–) and clinically stable → no separation, no evaluation of baby, INH prophylaxis for 9 months
• If mother has suspected TB at delivery → separate baby from mother until chest x-ray obtained
  • If mother has disease → treat infant with INH with no further separation from mother and treat mother with anti-TB therapy until culture negative for 3 months

 

 

LYME DISEASE

A 6-year-old child presents with a rash after camping on Long Island with his family. On physical examination, the rash has a red raised border with central clearing.

 

 

Borrelia burgdorferi

• Most common vector-borne disease in the United States
• Most in southern New England, eastern Middle Atlantic states, and upper Midwest, with small endemic area along the Pacific coast
• Ixodes scapularis, e., the deer tick
• Clinical presentation
  • History of tick bite is helpful, but absent in
  • Tick is small and often not seen by the human
  • History of being in the woods or mountains should give
• Early disease
  • Local: erythema migrans 3–32 days after bite at the site of the bite; target lesion (must be >10 cm in diameter) often called “bulls-eye” rash

} Fever, headache, and malaise most common symptoms

} Without treatment, the lesion resolves in 1–2 weeks

• Early disseminated: secondary lesions, smaller than the primary plus consti- tutional symptoms plus lymphadenopathy

} Uveitis and Bell palsy (may be only finding); carditis (myocarditis, heart block)

} CNS findings (neuropathy, aseptic meningitis)

• Late disease: arthritis weeks to months later; affecting large joints, more likely to be chronic in adults
• Diagnosis
  • No definitive tests
  • Primarily clinical and based on history + rash

–     Quantitative ELISA test and confirmatory Western blot if the ELISA is positive or equivocal

• Treatment
• Early

º Doxycycline 14–21 days (patients >8 years old); amoxicillin (patients age <8 years)

• Ceftriaxone with meningitis or carditis (heart block)
• Doxycycline or amoxicillin with Bell palsy
• Prognosis—excellent in children with permanent cure

 

 

ROCKY MOUNTAIN SPOTTED FEVER

A 17-year-old presents to the emergency center with his friends because of fever, headache, and a rose-colored rash that began on his ankles and is spreading. The patient and his friends have been camping in Virginia.

 

Rickettsia rickettsii

• Consider in differential diagnosis of fever, headache, and rash in summer months, especially after tick exposure
• Seen now in every state; most in Southeast, especially in North Carolina
• Wooded areas, coastal grasses, and salt marshes
• Most April–September; most patients age <10 years
• Ticks are the natural hosts, reservoirs, and vectors (dog tick, wood tick, brown dog tick).
• Clinical presentation
  • Incubation period 2–14 days, then headache, fever, anorexia, myalgias, gastrointestinal (GI) symptoms early
  • After third day—skin rash
    • Extremities first (palms, soles)
    • Spreads rapidly
    • Becomes petechial/hemorrhagic
    • Palpable purpura
  • Vascular obstruction, due to vasculitis and thromboses, leads to gangrene
  • Hepatosplenomegaly
  • CNS: delirium, coma, and other neurologic findings
  • Myocarditis, acute renal failure, pneumonitis, shock
  • Severe or fatal disease usually due to delay in diagnosis and treatment
• Diagnosis

–      Strong clinical suspicion

• Confirm with serologic tests; fourfold increase in antibody titer (acute, conva- lescence)

• Treatment—doxycycline or tetracycline in all patients regardless of age (chloram- phenicol in allergy only)

 

 

MYCOTIC INFECTIONS

 

Candida

A newborn infant is noted to have white plaques on his buccal mucosa that are difficult to scrape off with a tongue depressor. When removed, a small amount of bleeding is noted by the nurse. The infant just received a course of empiric antibiotics for suspected Group B b-hemolytic Streptococcus infection.

 

 

• Most human infections with albicans; part of normal gastrointestinal tract and vaginal flora of adults
• Oral infection = thrush; white plaques; seen with recurrent or continuing antibiotic treatment and immunodeficiency and normally in breast-fed infants
• Diagnosis—punctate bleeding with scraping
• Treatment—oral nystatin; if recalcitrant or recurrent, single-dose fluconazole

phil.cdc.gov

 

Figure 22-1. Diaper Rash Secondary to Candida Albicans Infection

 

• Diaper dermatitis: intertriginous areas of perineum; confluent, papular erythema with satellite lesions
• Diagnosis—skin scrapings; see yeast with KOH prep, but not usually necessary in the presence of clinical findings
• Treatment—topical nystatin; if significant inflammation, add 1% hydrocortisone for 1–2 days
• Catheter-related fungemia can affect any organ; may look like bacterial sepsis
• Diagnosis—buffy coat, catheter tips, urine shows yeast, culture
• Treatment—remove all catheters; amphotericin B is drug of choice
• Chronic mucocutaneous candidiasis—primary defect of T lymphocytes in response to Candida; often when endocrine (diabetes mellitus) and autoimmune disease

 

Cryptococcus neoformans

• Soil contaminated with bird droppings, or in fruits and vegetables
• Predominant fungal infection in HIV patients; rare in children and immuno- competent
• Inhalation of spores; in immunocompromised (mostly in HIV patients) disseminated to brain, meninges, skin, eyes, and skeletal system; forms granulomas
• Pneumonia most common presentation; asymptomatic in many; otherwise, progressive pulmonary disease

 

 

• Diagnosis
  • Latex agglutination—cryptococcal antigen in serum; most useful for CSF infections
• Treatment
  • Oral fluconazole for 3–6 months if immunocompetent and only mild disease
  • Amphotericin B + flucytosine if otherwise
  • In HIV—lifelong prophylaxis with fluconazole

 

 

Histoplasmosis

A 10-year-old presents to the physician with flu-like symptoms for the past 6 days. His mother notes fever, cough, and malaise. Further history reveals that he is upset because he likes to play in the mountain caves with his friends and has not been able to do so recently.

 

• Histoplasma capsulatum—soil contaminated with bird droppings or decayed wood; throughout Midwest, especially Ohio and Mississippi River valleys; bat droppings in caves
• Inhalation of micronidia—proliferate as yeast
• Initially, bronchopneumonia (granuloma and central necrosis); disseminates through reticuloendothelial system; resolves over 2–4 months; may calcify and look like TB
• Clinical presentation

–      Acute pulmonary histoplasmosis

• Most asymptomatic
• Symptomatic in young children—flu-like symptoms; possible significant respiratory distress
• Hepatosplenomegaly
• Most have normal CXR; if symptomatic: patchy bronchopneumonia and hilar adenopathy

• Chronic pulmonary histoplasmosis—seen in adults (rarely in children) and is a centrilobular emphysema due to histoplasmosis infection

• Diagnosis
  • Most widely available test is radioimmunoassay; serum or urine for the antigen is positive in vast majority

–      Seroconversion

• Treatment
  • None for mild acute disease
  • If without improvement: oral itraconazole

-Progressive pulmonary disease or disseminated infection should be treated with amphotericin B.

 

 

Coccidioidomycosis (San Joaquin Fever; Valley Fever)

A 14-year-old who lives in Arizona presents to the physician with a 10-day history of fever, headache, malaise, chest pain, and dry cough. He is currently in New York visiting relatives and is accompanied by his aunt. Physical examination reveals a maculopapular rash and tibial erythema nodosum.

 

 

• Inhaled arthroconidia from dust; no person-to-person spread
• Types
• Primary (self-limiting)
• Residual pulmonary lesions (transient cavity or chest x-ray)
• Disseminating—can be fatal; more common in males, Filipino/Asians, blood group B
  • Influenza-like symptoms
  • Chest pain

–                                                                                    Dry, nonproductive cough

• Maculopapular rash

º      Tibial erythema nodosum

• Diagnosis
• Sputum should be obtained via bronchoalveolar lavage or gastric
• Diagnosis is confirmed by culture, PCR
• Treatment—most conservative; for those at high risk of severe disease, treatment as with histoplasmosis

 

 

VIRAL INFECTIONS

 

Viral Exanthematous Disease

phil.cdc.gov.

 

Figure 22-2. Typical Appearance of Morbilliform Rash Seen in Measles Infection

 

 

 

 

 

 

 

 

 

Disseminated Coccidiomycosis Triad

1. Flu-like symptoms +/– chest pain
2. Maculopapular rash
3. Erythema nodosum

 

 

Measles

A mother presents to the physician with her adopted daughter, who has just arrived in the United States from a foreign country. The immunization record is not up-to- date. The child has coryza, cough, conjunctivitis, and fever. The mother states that the child also has a rash that began cephalad and spread caudad. On physical examination, a morbilliform rash is seen over the body including the palms. Tiny grayish white dots are seen on the buccal mucosa next to the third molar.

 

• Rubeola—10-day measles
• RNA Paramyxovirus, very contagious
• Risk factors—Unimmunized entering high school or college
• Incubation—10–12 days before prodrome appears
• Prodrome—3 C’s
  • Cough
  • Coryza
  • Conjunctivitis, then Koplik spots (grayish-white spots on buccal mucosa)
• Final—rash + fever (occur concurrently)
  • Rash—macular; starts at head (nape of neck and behind ears) and spreads downward; fades in same manner
• Diagnosis—mainly clinical
• Treatment—supportive, vitamin A (if deficient)
• Complications—otitis media (most common), pneumonia, encephalitis
• Prevention—immunization

 

 

Rubella

A 5-year-old child who has delayed immunizations presents with low-grade fever, a pinpoint rash, postoccipital and retroauricular lymphadenopathy, and rose spots on the soft palate.

 

• German, 3-day measles
• Risk factors/Etiology—Incubation 14–21 days; contagious 2 days before rash and 5–7 days after rash
• Clinical Presentation
  • Rash similar to measles, begins on face and spreads to rest of body, lasts approxi- mately 3 days; concurrent with fever
• Retroauricular, posterior, and occipital lymphadenitis are
• Forscheimer spots—affect the soft palate and may appear before onset of the rash
• Polyarthritis (hands) may occur in some patients, especially older
  • Diagnosis—clinical
  • Treatment—supportive

 

 

• Prevention—immunization with MMR vaccine
• Complications—congenital rubella syndrome seen if contracted during pregnancy (see Newborn chapter)

 

 

Roseola

A 15-month-old infant is brought to the physician because of a rash. The mother states that the patient had a fever of 40°C (104°F) for the last 3 days without any source of infection. She explains that the fever has resolved, but now the child has pink, slightly raised lesions on the trunk, upper extremities, face, and neck.

 

• Also known as exanthem subitum
• Etiology—febrile illness of viral etiology; due to infection with human herpes virus—HHV-6; peaks in children age <5 years, usually 6–15 months; incubation period 5–15 days
• Clinical Presentation
  • High fever (up to 41°C [106°F]) lasting a few days with only signs and symptoms of URI
  • By the 3rd or 4th day, the fever resolves and a maculopapular rash appears on the trunk, arms, neck, and face
    • Characteristic rose-colored rash begins as papules
  • Diagnosis and treatment—clinical diagnosis based on age, history, and physical find- No studies necessary and treatment is supportive.

 

 

Mumps

A 4-year-old child is brought to the clinic by his mother with a history of swelling in his face and fever for the last 4 days. His history includes incomplete immunizations due to religious beliefs. Physical examination reveals bilateral, tender facial swelling around the area of the masseter muscle and fever of 39.3°C (102.8°F).

 

• Etiology/Risk Factors—viral infection due to Paramyxovirus transmitted through air- borne droplets and respiratory/oral
  • Most common in winter/spring
  • Incubation period from 14–24 days
  • Contagious 1 day before and 3 days after swelling appears
  • History usually reveals inadequate or lacking immunizations
• Clinical Presentation
  • Constitutional findings: fever, headache, and malaise
  • Unilateral or bilateral salivary gland swelling, predominantly in the parotids
  • Orchitis (and oophoritis) possible, rare before puberty
    • May result in sterility only if bilateral

 

 

• Diagnosis—clinical and based upon history/physical findings
• Treatment—supportive
• Meningoencephalomyelitis most common complication; others include pancreatitis, thyroiditis, myocarditis, deafness, and dacryoadenitis

 

 

Varicella

phil.cdc.gov

 

Figure 22-3. Chicken Pox is Characterized by Macules, Papules, Vesicles, and Crusts in Varying Stages of Healing

 

A 5-year-old child is brought to the emergency center because he has a temperature of 38.9°C (102°F) and is developing a pruritic rash. The rash appears to be in various stages of papules, vesicles, and crusts. It began on his trunk and spread to his extremities.

 

• Etiology/Risk Factors—due to varicella-zoster virus, a herpes virus
  • Incubation 10–21 days
  • Transmitted through respiratory secretions
  • Remains latent in sensory ganglia after recovery → reactivation in immuno- suppressed
• Clinical Presentation—nonspecific symptoms and fever preceeding rash

–  Pruritic rash in various stages

• Macules → papules → vesicle → open vesicle → crust
• Lesions can turn

º      Crops of lesions at same time

• Clinical diagnosis—no labs
• Treatment
  • Supportive in immunocompetent; treat secondary infection
  • Consider acyclovir and VZIG in immunocomprised or those at risk for severe disease

 

 

• Complications—worse in adolescence (scarring)
  • Varicella pneumonia seen in 15–20%
  • Other sequelae include Guillian-Barré syndrome, encephalitis, cerebellar ataxia, post-herpetic neuralgia, and Ramsay-Hunt
  • Congenital varicella (see Newborn chapter)
• Prevention—second vaccine dose recommended

 

 

Erythema Infectiosum (Fifth Disease)

A 4-year-old is brought to the physician’s office because she developed red cheeks that appear as if someone has slapped her, and a lacy rash on her upper extremities and trunk.

 

• Etiology—due to Parvovirus B19, a DNA virus; seen most commonly in spring
• Clinical Presentation
  • Mild systemic symptoms
  • Arthritis
  • Intensely red “slapped cheek” appearance
  • Lacy, reticular rash over trunk and extremities
  • Sparing of palms and soles
  • Rash may last up to 40 days
• Diagnosis—clinical; labs not routine except when diagnosing hydrops, then viral DNA in fetal blood is often helpful
• Complications—aplastic crisis in patients with hemolytic anemia; hydrops fetalis in neonates during materal infection in first trimester

 

 

Table 22-2. Common Childhood Infections with Exanthems

	Prodrome	Enanthem	Exanthem	Complications
Measles	•    Cough •    Coryza •    Conjunctivitis •    High fever	Koplik spots	Macules: hairline, face, neck → trunk and extremities	•    Otitis media •    Pneumonia •    Encephalitis •    Subacute sclerosing panencephalitis
Rubella	Mild constitutional symptoms	Forscheimer spots	•    Similar to measles •    Posterior cervical & auricular nodes	Congenital rubella– teratogenic
Mumps	•    Headache •    Fever •    Malaise •    Muscle pain	Glandular swelling	Swollen parotid & submandibular glands	•    Encephalitis •    Orchitis •    Pancreatitis
Varicella	•    Low-grade fever •    Malaise •    URI symptoms	None	•    Crops of papules, vesicles •    Crusts at same time •    Central to peripheral	•    Superinfection •    Zoster •    Pneumonia •    Hepatitis •    Encephalitis •    Congenital varicella
Fifth Disease	Mild URI symptoms	None	Slapped cheek → trunk → central clearing-lacey	Aplastic anemia
Roseola	•    URI symptoms •    Abrupt onset •    High fever then breaks	None	Fever falls rapidly → fine macular rash on trunk and spreads to extremities	Febrile seizures
Scarlet Fever	Sore throat	•    Exudative pharyngitis •    Strawberry tongue	•    Fine maculopapular rash (feels like sand paper, especially in antecubitus and inguinal areas) •    Pastia lines	•    Acute rheumatic fever •    Glomerulonephritis

 

 

OTHER VIRAL DISEASES

 

Epstein-Barr Virus

A 22-year-old college student presents to the clinic complaining of fever, fatigue, and sore throat that have not improved for the last 2 weeks. Physical examination reveals generalized adenopathy most prominent in the anterior and posterior cervical nodes.

 

 

 

• Etiology/Risk Factors

–  Infectious mononucleosis (90%)

• First human virus to be associated with malignancy
  • Nasopharyngeal carcinoma

º      Burkitt lymphoma

• Others: Hodgkin disease, lymphoproliferative disorders, and leiomyosarcoma in immunodeficiency states

• Transmitted in oral secretions by close contact (kissing disease); intermittent shedding for life
• Incubation period: 30–50 days; most cases in infants and young children are clinically silent

• Clinical presentation
• Insidious, vague onset: prodrome for 1–2 weeks with fever, fatigue, headache, myalgia, sore throat, abdominal pain
• Generalized lymphadenopathy (most in anterior and posterior cervical and submandibular nodes; less often in axillary, inguinal, epitrochlear nodes), spleno- megaly (half the cases; 2–3 cm), and a small number with hepatomegaly
• Moderate to severe pharyngitis with tonsillar exudative enlargement
  • Small number with rashes (maculopapular); most will have rash if treated with

ampicillin or amoxicillin (immune-mediated vasculitic rash)

• Diagnosis

–     Atypical lymphocytosis

• Heterophile antibodies (Monospot test)
• IgM to viral capsid (Igm–VcA–EBV) antigen is the most valuable and specific (up to 4 months).
• Treatment
• Rest and symptomatic therapy

–     No contact sports or strenuous activity with splenomegaly

• Short course of steroids for complications: incipient airway obstruction, thrombo- cytopenia with hemorrhage, autoimmune hemolytic anemia, seizures, meningitis
• Complications
• Splenic hemorrhage or rupture (very rare); most in second week, most with trauma
• Swelling of tonsils and oropharyngeal lymphoid tissue: airway obstruction
  • Neurological complications rare; Guillain-Barré syndrome
• Aplastic anemia

 

 

 

Infectious Mononucleosis Triad

1. Fatigue
2. Pharyngitis
3. Generalized adenopathy

 

 

 

 

 

 

 

 

 

 

 

Note

Any question on the Step 2 exam that mentions onset of rash after taking ampicillin or amoxicillin for URI-related symptoms, think mono first.

 

 

• Interstitial pneumonia
• Myocarditis

• Prognosis

-Most cases resolve in 2–4 weeks; some disability that comes and goes for a few months is common; and there may be fatigue for a few years

-There is no evidence of second attacks from EBV and no evidence that EBV is related to chronic fatigue syndrome

 

 

Influenza Viruses

A 14-year-old girl is brought to the physician’s office by her mother. She has a 2-day history of fever of 39.7°C (103.5°F), headache, sore throat, refusal to eat, myalgia, chills and non-productive cough. Her current temperature in the clinic is 39.3°C (102.8°F).

 

• Etiology/Risk Factors
  • Three types—A, B, and C, with A and B being the primary pathogens of epidemic disease; now, also since 2009, H1N1
  • Migratory avian hosts may be responsible for
  • Annual spread between Northern and Southern hemispheres; origin of new strains often traced to Asia
  • One or two predominant strains spread annually
  • Attack rate highest in the young; colder months in temperate climates
  • Transmission by small particle aerosol
• Clinical presentation
• Predominantly respiratory illness
• Abrupt onset with coryza, conjunctivitis, pharyngitis, and dry cough
• Prominent systemic signs: fever (2–4 days), myalgia, malaise, headache
• Diagnosis
• Virus can be isolated from nasopharynx early in
• Rapid diagnostic test: ELISA
• Can be confirmed serologically with acute and convalescent titers or PCR
• Treatment
• Rest and adequate fluid intake
• Control of fever
• Antiviral drugs: decrease severity and duration if administered within first 48 hours of symptoms
• Complications—otitis media, pneumonia; secondary bacterial infection, myocarditis

 

 

Coxsackievirus

A 2-year-old infant is brought to the clinic with a vesicular rash in his mouth and on his palms and soles. Examination reveals a rash on his buttocks.

 

• Etiology/Risk Factors—due to infection with coxsackievirus A16
• Clinical diagnosis: Characteristic lesions—seen anywhere but especially on the oral mucosa, hands and feet; hand-foot-mouth Rash on the buttocks is common.
• Coxsackievirus B also responsible for viral myocarditis
• Treatment is supportive care

 

Copyright 2007 – Custom Medical Stock Photo.

 

Figure 22-4. Oral Ulcers of Hand-Foot-and-Mouth Disease

 

 

Adenovirus

A 12-year-old patient presents with fever, sore throat, and follicular conjunctivitis.

 

• Etiology/Risk Factors—DNA virus responsible for URIs in infants and children
• Clinical Presentation—Fever, pharyngitis, conjunctivitis, and diarrhea are

– Less common features include pharyngoconjunctival fever, myocarditis, and intussusception.

• Diagnosis—serology, viral culture, or PCR, but not usually necessary
• Treatment—supportive

 

Poliovirus

• Etiology/Risk Factors—lives in gastrointestinal track
• Clinical Presentation—can cause URI symptoms
  • Paralytic polio

º  Asymmetric flaccid paralysis

• Prevent with vaccination

 

 

Acquired Immunodeficiency Syndrome (AIDS)

An 18-month-old has failure to thrive and developmental delay. The patient also has a history of recurrent ear infections, oral thrush, and chronic diarrhea. The patient on physical examination today is noted to have lymphadenopathy.

 

• Etiology/Risk Factors
  • Most are children born in developing countries; acquired at birth from an HIV- positive mother
  • Breast feeding in developing countries is an important route of
  • Pregnant females in United States and other developed countries are routinely screened for HIV infection in prenatal labs, unless the patient

º Early treatment and prevention of neonatal infection through anti-retroviral therapy and preventive measures during delivery/postpartum period

• Clinical presentation
  • HIV-infected newborns: rapid onset of symptoms and AIDS in first few months of life
• Initial symptoms may include
  • Lymphadenopathy
  • Hepatosplenomegaly
  • Failure to thrive
  • Chronic diarrhea
  • Interstitial pneumonia
  • Oral thrush
• Children > adults: recurrent bacterial infections, chronic parotid swelling, lym- phocytic interstitial pneumonitis, early progressive neurological deterioration
• Infections

–      Recurrent bacterial infections with encapsulated organisms and other gram- positive and gram-negative organisms

• Opportunistic infections; most common is PCP (onset of fever, tachypnea, dyspnea, and marked hypoxemia)
• Mycobacterium avian-intracellulare complex: disseminated disease in severely compromised
• Oral candidiasis and other invasive fungal infections
• Viral infections, especially herpes group
• Other problems
• CNS disease
• Cardiomyopathy
• Enteropathy
• Wasting syndrome, nephropathy
• Many cutaneous manifestations
• All hematologic manifestations, malignancies
• Diagnosis

–      HIV-DNA by PCR

 

 

– Maternal HIV IgG antibodies cross the placenta

º Screen will be positive in all newborns up to age 18 months so need 2 of 3

Å PCR for HIV in first month of life.

• In any child >18 months of age: test for infection through IgG Ab by ELISA and then confirm with Western blot to establish the

• Treatment—infants born to HIV-infected mothers
• Mother should be on perinatal triple anti-retroviral therapy and then IV ZDV at start of labor until cord is clamped
• Infant should be started on ZDV (birth) until neonatal disease is excluded
  • Also start PCP prophylaxis (TMP-SMZ) at 1 month until disease excluded
  • Follow CBC, platelets, CD4 and CD8 counts
  • With symptoms or evidence of immune dysfunction, should be treated with

antiretroviral therapy, regardless of age or viral load

• Prognosis
  • Best single prognostic indicator is the plasma viral
  • Mortality higher with CD4 count <15%
  • Poor prognosis with persistent fever and/or thrush, serious bacterial infection (men- ingitis), hepatitis, persistent anemia, and/or thrombocytopenia (30% die by age 3)
  • Children with opportunistic infection, encephalopathy, or wasting syndrome have the worst prognosis (75% die by age <3)

 

 

HELMINTHIC DISEASES

 

Ascariasis

A child is brought to the physician’s office because his mother found a “worm” while changing his diaper. He also has a chronic cough with pinkish sputum.

 

 

• Etiology/Pathogenesis—Ascaris lumbricoides; nematode (roundworm)
  • Most prevalent human helminth in the world
• High prevalence in poor socioeconomic status countries, with use of human waste as fertilizer, and with geophagia (highest in preschool age)
• Travels to the small intestines → releases larvae → migrates through venous circula- tion to lungs and causes pulmonary ascariasis (Loeffler syndrome) → through alveoli and bronchi to trachea and are swallowed mature in intestine to adult worms
• Clinical Presentation—most asymptomatic or mild

–  Most common symptom is pulmonary disease—cough and blood-stained sputum

• Followed by obstructive intestinal or biliary tract disease

º  May have colicky abdominal pain or bile-stained emesis

• CBC reveals significant blood eosinophilia
• Can be identified on fecal smear
• Treatment—albendazole, mebendazole, or pyrantel pamoate

 

 

 

Note

Loeffler syndrome = pulmonary ascariasis plus hemoptysis

 

 

Hookworm

A 5-year-old girl is brought to the physician due to lack of appetite, abdominal pain, and diarrhea. On physical examination a yellow-green pallor is noted.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note

Most parasites, ova, and cysts can be identified on fecal smear.

 

• Etiology/Risk Factors—Ancylostoma and Necator americanus are nematodes trans- mitted through warm, moist soil; usually in rural areas where human waste is used as
• Penetrate through the skin (leads to intense pruritis at site of entry) or are ingested
• Migration through veins to lungs and are swallowed → have teeth to attach to mucosa and can remain up to 5 years, where they mate and produce eggs
• Clinical Presentation—Morbidity from blood loss

–  Iron deficiency anemia

• Hypoalbuminemia → edema, anasarca
• Also, cough, colicky abdominal pain, anorexia, diarrhea
• Physical growth retardation, cognitive and intellectual deficits
• Green-yellow skin discoloration known as chlorosis and seen in chronic infection
• Labs reveal significant blood eosinophilia.
• Eggs can be identified on fecal
• Treatment—mebendazole or albendazole is drug of choice; pyrantel pamoate an alternative

– Ferrous sulfate if iron deficient

 

 

Enterobiasis

A mother brings her 4-year-old child to the physician with a history of always scratching her anus. The mother is embarrassed by this behavior. The child attends daycare and loves to play in the sandbox.

 

• Etiology—Enterobius vermicularis is the parasite implicated in pinworm
• Small, white, threadlike nematodes
• Most common helminth in the United States
• Primarily in institutional/family settings that include children; highest at age 5–14
• Eggs are ingested from being carried on fingernails, clothing, bedding, or house dust; after ingestion, adult worms within 1–2 months
• Inhabits cecum, appendix, ileus, and ascending colon; female migration at night to deposit eggs on perianal region and perineum
• Clinical Presentation—most common symptoms include itching and restless sleep

and no eosinophilia

• Diagnosis—history and use of adhesive cellophane tape (tape test) at night when child is asleep
• Treatment—infected person and entire family receive single oral dose of mebenda- zole and repeat in 2 weeks