infectious process leading to inflammation and edema of the vocal cords and subglottic tissues which results in glottic narrowing (steeple sign on CXR)
affects ages 8-30 mos; male>female
Etiology
: mainly parainfluenza virus 1 or 2; also RSV, Influenza A; seasonal, tend to have yearly epidemics in the fall
Symptoms/Signs
: starts as a cold, progresses to barky cough (sounds like a seal), stridor
Diagnosis
: labs aren’t helpful, AP neck film may show glottic narrowing (steeple sign)
Treatment
: self-limited in 7-14 days; supportive therapy (humidifier may ß Sx); epi may ß edema, steroids ß inflammation
severe disease may require airway treatment
Bacterial Tracheitis
bacterial infection usually secondary to parainfluenza (viral croup)
Etiology
: staph aureus mainly, also H. flu or pneuomococcus; affects all ages, including adults
: Ý WBC; lateral neck films show irregular membrane in air column; may be able to isolate organism
Treatment
: antibiotics, artificial airway
Epiglottitis/Suproglottitis
Etiology
: H. flu (rarely other bugs, never viral) infection Þ supraglottic swelling of the epiglottis and aryepiglottic folds; peak incidence 18 mos - 8 yrs; now rare because of Hib vaccination
Syptoms/Signs
: little prodrome; febrile, toxic-looking; stridor, drooling, hoarseness, upright posture
: EMERGENCY; secure airway, then antibiotics; mortality is 25% if airway not secured
Pertussis
Etiology
: Bordatella pertussis infection of upper and lower airways; toxin production and destruction of cilliated epithelium leads to cough, respiratory distress; possible apnea, pneumonia, CNS abnormalities
female > male; affects all ages, but < 1 yr is most serious
Symptoms/Signs
:
Catarrhal stage: fever, rhinorrhea, cough (basically a cold)
Paroxysmal stage: severe paroxysmal cough (whooping cough), apnea
Convalescent stage: cough subsides somewhat
the last two stages can last for months, leading to severe long-term damage
Diagnosis
: organsim can be cultured only during first 7 days; Ý lymphocyte count; fluorescent Ab count
Treatment
: erythromycin, ampicillin; antibiotics shorten the course if given in first two stages; eliminate NP carriage in all stages
Cellular vaccine
: suspension of killed organisms; 80-85% effective, immunity wanes over time, high adverse effects
Acellular vaccine
: uses four antigens, very effective and much safer than cellular vaccine
Respiratory Syncytial Virus (RSV)
the big one!; the most important pathogen in children; accounts for up to 40% pneumonias, 90% of brochiolitis in children under 2 yrs; 95,000 yearly hospitalizations, and 5,000 deaths
serologic evidence of infection in 95% of children at 5 yrs; affects adults as well as children
most serious infections in children 6 wks - 2 yrs (peak at 2 mos); most severe < 6 mos
risk factors: female, low socioeconomic status, living with smoker
follows seasonal pattern, usually 5 mos in the winter; when it hits, RSV is the only player in town
Brochiolitis
: accounts for majority of RSV-induced illness; URI in adults and older children, LRTI in infants
hypoxemia, atelectasis, and pneumonia are also common
neonates may present with sepsis-like picture and no respiratory symptoms/signs
usually self-limiting in 1 wk, but pneumonia often follows
Diagnosis
: viral culture is the gold standard for definitive diagnosis; immunofluorescence is 95% sensitive, ELISA is 78% sensitive and much easier to perform than immunofluorescence
BUT, these methods take time and $
Þ diagnosis is usually based on clinical and seasonal observation
Morbidity/Mortality
sequelae can be asthma and reactive airway disease; almost all patients have
ß PFTs for years after infection
apnea often occurs, and is more common in premies and infants under 18 mos
2% mortality in infants with lower respiratory infection (
Ý mortality in congenital heart disease, immunocomp)
Transmission
: via large droplets and contaminated secretions; virus is usually brought into the home by an older sibling; nosocomial infection is a big problem (32% of patients, 43% of staff); the virus survives longest on countertops, and longer on gloves than on hands Þ the solution: handwashing, don’t touch your eyes or nose in PEDS
Treatment
immunity develops poorly, you need three rapid infections to get any kind of protection, and it fades rapidly
no successful vaccine has been developed
IV IgG
has been shown to shorten the course, but morbidity/mortality was not improved, and hospital stay and $ Ý Ý
currently recommended only for high risk patients (former premies, congential heart disease)
Ribavirin
: triazole nucleoside interferes with viruses Þ mild clinical success, high cost, difficult to administer