IOD URTI Flashcards
Rhino sinusitis 4 details?
Very common, self-limiting
Winter > summer
Children > adolescents > adults > elderly
Primarily viral; 2% develop bacterial infection
Rhinosinusitis-bacterial suspected?
symptoms >7 days or worsening, facial pain, purulent secretions
Rhinosinusitis bacterial causative organisms?
S. pneumoniae – 40-60% H. influenzae – 20% M. catarrhalis – 20% Other streptococci, S. aureus, anaerobes – 20% can be mixed
Rhinosinusitis viral causative organisms?
rhinoviruses»_space; respiratory syncytial virus (RSV), coronaviruses, enteroviruses, adenoviruses
Management of rhinosinusitis?
Symptomatic relief – paracetamol for pain / fever; decongestants can be used but tachyphylaxis (tolerance to dose) develops
PO amoxicillin 500mg TDS OR PO clarithromycin 500mg BD 5-7 days can be used
Prognosis of rhinosinusitis?
Usually uncomplicated, rarely spreads to surrounding structures
Consider immunological and structural factors if persistent / recurrent
Pharyngitis info?
Viral most common; ~15% bacterial
Clinically difficult to distinguish
CP of pharyngitis?
Sore throat, dysphagia / odynophagia, swollen tonsils, palatal petechiae
CP of bacterial pharyngitis?
Bacterial more likely with high fever, tender cervical lymphadenopathy, severe exudative pharyngitis
Which CP indicates scarlet fever?
Petechial rash, strawberry tongue
causative organisms for pharyngitis?
Viruses as for rhinosinusitis but also EBV, CMV (mononucleosis / glandular fever)
Adenovirus: pharyngoconjunctival fever
Enteroviruses: herpangina
β-haemolytic streptococci (esp. Group A)
Anaerobes (fusobacteria sp.)
Group A strep can be associated with rheumatic fever and glomerulonephritis
Management of pharyngitis?
Viral self-limiting – symptomatic treatment with paracetamol; lozenges
PO penicillin V 500mg QDS OR clarithromycin 500mg BD for suspected streptococcal (NB treat for 10 days to eradicate carriage)
Diphtheria facts?
Toxigenic bacterial URI, occasionally affects skin
Now rare in developed countries (vaccination)
Epidemics in Russia, E. Europe latter 20th century
Vaccine immunity wanes; adults are susceptible if exposed
Cause of diphtheria?
toxigenic strains of Corynebacterium diphtheriae / ulcerans
CP of diphtheria?
Pharnygeal / tonsillar – most common
Sore throat, grey / blue exudative pharyngeal membrane, difficult to remove
Neck and jaw oedema (bull neck appearance)
Respiratory obstruction
Cardiac failure
Paralysis
Cutaneous (commoner in tropics)
Vesicular ulcerating lesion on extremity, well-demarcated, painful
Chronic and difficult to treat
Other forms: laryngeal, ear, conjunctival, genital
Pathophysiology of diptheria?
Classical AB-type toxin
B – binding to host receptor
A – active enzymatic subunit
Catalytic subunit A is an ADP-ribosyltransferase that inactivates elongation factor 2 (EF2) halting protein synthesis and killing host cell
Inactivated toxin (toxoid) used in vaccination
Novel therapeutic uses include using DT to kill cancer cells
management of diptheria?
travel history
isolation
Confirm diagnosis with culture: pharyngeal swab, selective media (inform lab)
Toxin detection (usually reference lab)
Antitoxin – equine (obtain from HPA)
Antibiotics: macrolides or penicillin
Prevention: vaccination (toxoid)-v. effective
How many households i n the UK are unprotected from diphtheria?
50%
Epiglottitis info?
Bacterial infection involving the epiglottis
Generally affects young children (2-7 years)
~95% reduction in incidence since Hib vaccine introduced in 1992
Most common cause of epiglottitis?
Haemophilus influenzae b is most common cause
CP of epiglottitis?
Acute onset of sore throat, dysphagia, fever, hoarseness / loss of voice
Child often unwell, sitting forward, tongue out, drooling
Stridor and respiratory distress may be present
Do not attempt to examine throat (may precipitate obstruction)
Management of epiglottitis?
Paediatric emergency – may require intubation – SEEK EXPERT ADVICE
Hib can sometimes be isolated from blood cultures
IV 3rd generation cephalosporin
LARYNGITIS/croup info?
Classically affects children 6 months – 6 years, peak age 2 years
Barking / bovine cough, worse at night
Adults may have persistent dry cough, hoarse voice
Preceded by rhinitis, pharyngitis, dysphagia / odynophagia
causes of laryngitis?
Nearly always viral
Parainfluenza viruses (1-3) – 80%
Other URI viruses
Bacterial infection rare, but remember Bordatella pertussis (whooping cough) and Corynebacterium diphtheriae (diphtheria)
pertussis info?
URI characterised by paroxysmal coughing of >14-21 days duration
Vaccine-preventable, but still a global health problem with increasing incidence
Immunity (vaccine or natural) is incomplete and not lifelong
UK currently experiencing a resurgence
epidemiology of pertussis?
young and old
CP of pertussis?
Catarrhal phase – indistinguishable from other URI, highly infectious
Paroxysmal phase – paroxysms of coughing, inspiratory ‘whoop’ may follow, vomiting, seizures, apnoeic episodes
Convalescent phase – resolution, but dry cough may persist for months
Usually uncomplicated, but children with lung disease or neurological disease at increased risk of death
managment of pertussis?
Admit if severe or high-risk
Confirm diagnosis with culture (pernasal swab), serology, or PCR
Antibiotics may hasten elimination of bacteria hence reduce spread, but unlikely to shorten disease once paroxysmal phase begins
Macrolides are treatment of choice
Prevention: vaccination (acellular pertussis vaccine, usually combined with DT)
Now offered to women during pregnancy (weeks 28-38)
otitis media info?
Acute otitis media (AOM) – acute inflammation of the middle ear
Bulging tympanic membrane / otorrhoea
Middle ear narrow chamber lined with respiratory mucosa – vulnerable as the rest of airway
Leading cause of GP consultation and antibiotic prescription
Peak incidence in under 2 years
Risk factors: age, FH, day care attendance, exposure to smoke; BF is protective
A otitis media pathophys?
Viral URTI or other antecedent inflammatory oedema of resp mucosa obstruction of Eustachian tube negative middle ear pressure accumulation of fluid microbial growth in fluid : suppuration
causes of otitis media?
Bacterial – S. pneumoniae, H. influenzae, M. catarrhalis; also Mycoplasma pneumoniae
Viral – as for any viral URTI but especially RSV
Universal conjugated pneumococcal vaccine has reduced the incidence of AOM due to vaccine serotypes
complications of otitis media?
Hearing loss and vestibular dysfunction due to effusion
Tympanic membrane perforation
Chronic suppurative otitis media (CSOM)
Perforation + chronic purulent drainage for > 6 weeks
End-stage of recurrent AOM
Cholesteatoma – abnormal growth of squamous epithelium in middle ear
Mastoiditis – extension of infection into adjacent bone
Intracranial infection or thrombosis
metaplasia from columnar to squamous
vaccine all-CI and precaution?
A confirmed anaphylactic reaction to a previous dose of the vaccine or to a component of the vaccine
If individual acutely unwell on day of vaccination, postpone until recovered
Pregnancy
DTP
same
If evidence of evolving neurological abnormality or current neurological deterioration, including poorly controlled epilepsy, immunisation should be deferred until condition stabilised
Influenza
same and confirmed anaphylactic hypersensitivity to egg products
thiomersal free influenza vaccines recommended for pregnant women and infants
Live vaccines
same
Immunocompromising treatment or condition
Pregnancy
If ITP following previous MMR vaccine, perform antibody test
If confirmed anaphylactic reaction to egg, seek further advice with view to immunisation under controlled conditions
risk of reactions vs disease for convulsions, ITP, SSPE and death?
see ppt
adr’s live vs inactivated?
Live vaccines: frequency of adverse events falls with number of doses
e.g. MMR if antibody is made in response to first dose of live vaccine, it neutralises the small amount of vaccine virus in any subsequent vaccine dose
Inactivated vaccines: frequency of adverse events increases with number of doses
e.g. tetanus if antibody levels are good following previous vaccination, the antibody binds to the vaccine antigen in a subsequent dose of vaccine making an inflammatory response (such as a sore arm)
timing live vs inactivated
Inactivated vaccines: generally within 48hrs following vaccination
Live vaccines: occur according to time taken for virus to replicate
risk groups live vaccines
Patients having chemotherapy for malignancy
Patients <6/12 after BMT
Children on high dose steroids +/- cytotoxics
Pregnant women (although no evidence of harm from MMR)
