Sore throat week 1 Flashcards
Acute pharyngitis:
less than two weeks duration
Chronic pharyngitis:
more than 2 weeks duration
Causes of pharyngitis:
Infectious:
-viral
-Bacterial
Non-infectious causes
Infectious pharyngitis
Most common cause of sore throat
Viral > bacterial
Sore throat caused by an infection:
-Viral
-Bacterial
-Fungal
Fungal pharyngitis is rare
Consider the patients:
-Who are immunocompromised
-With chronic steroid or antibiotic use
Viral pharyngitis:
Infection of pharynx by a virus.
Most common cause: common cold:
-At least 25% of cases due to rhinoviruses and coronaviruses
Bacterial pharyngitis:
Infection of pharynx by bacteria.
Most common cause: Group A beta-hemolytic streptococci (GABHS):
-5-15% of sore throats in adults
-20-30% sore throats in. children (ages 5-15)
Frequency and clinical syndrome for infectious causes of sore throat:
Distribution of causes of sore throat in children:
Non-infectious pharyngitis:
Consider in patients:
-with chronic sore throat
-without signs of infection
-Who do not respond to treatment
General approach to acute pharyngitis:
-Rule out serious diagnosis and red flags/alarm symptoms that prompt emergent/urgent management
-Most cases of acute pharyngitis are due to infectious cause-determine the specific infectious cause (ex. Viral or bacterial)
-Identify acute sore throat caused by group A beta-hemolytic streptococcal (GABHS) pharyngitis:
-antibiotic treatment may be indicated
What is a red flag or alarm symptom/sign?
red flags are signs and symptoms found in the patient history and clinical examination that may indicate possible serious underlying pathology.
Red flags prompt further investigation and/or referral.
Acute epiglottitis:
-Rare but potentially fatal condition
-Inflammation of epiglottis adjacent tissues
-Bacterial infection primarily caused by Haemophilus influenzae
-In the past, most commonly seen in children aged 2-6: HiB vaccination in infants has decreased incidence
-Most common in winter and spring
-Positive thumb sign on lateral radiograph of the neck is diagnostic
-Medical emergency => refer
-Airway management is key to prevent airway compromise: may require intubation
-Requires antibiotic therapy
Acute epiglottitis: Clinical representation:
-Acute onset fever, severe sore throat, toxic appearance
The 4 D’s:
-Dysphagia (difficulty swallowing)
-Drooling
-Dysphonia (muffled, hoarse, abnormal voice)
-Distress (inspiratory stridor, tripod position, severe dyspnea, irritability, restlessness)
**Do not use a tongue depressor when examining the oropharynx as it can precipitate airway obstruction.
Peritonsillar abscess:
Aka: quinsy
-Most common deep infection of head and neck (30% of abscesses of head and neck)
-Most common in young adults (ages 20-40); Increased risk in immunocompromised and diabetics
-Usually begins as acute tonsillitis => cellulitis => abscess formation
-Polymicrobial infection: common organisms: Group A streptococci, staphylococcus aureus, Haemophiles influenzae, fusobacterium, peptostreptococcus, pigemented prevotella species, veillonella
-Diagnosis can be made clinically without labwork/imaging in patients with typical presentation
Peritonsillar abscess: clinical presentation:
Severe unilateral sore throat:
-Dysphagia and odynophagia => pooling of saliva or drooling
-Fever and malaise
-Dysphonia: muffled “hot potato” voice
-Rancid or fetor breath
-Otalgia
-Trismus (66% of patients)
-Oropharyngeal exam: erythematous enlarged tonsil and bulging soft palate on affected side, uvular deviation to contralateral side
-May have severely tender cervical lymphadenopathy
Peritonsillar abscess: diagnosis:
Culture of pus from abscess drainage confirms diagnosis.
Imaging not necessary to confirm diagnosis:
-CT with IV contrast (LR+ 4, LR- 0)
-Intraoral ultrasonography (sensitivity 89-95%, specificity 79-100%)
Treatment includes drainage, antibiotic therapy, supportive care
Retropharyngeal abscess:
Retropharyngeal edema due to cellulitis and suppurative adenitis of lymph nodes in retropharyngeal space.
-Preceded by upper respiratory infection, pharyngitis, otitis media, wound infection following penetrating injury to posterior pharynx
Peak incidence in 3-5 year olds
Observed as prevertebral soft-tissue thickening on lateral X-ray of neck
Treat as impending airway emergency:
-requires antibiotic therapy, possible surgical consultation for needle aspiration or incision and drainage
Retropharyngeal abscess: clinical presentation:
Sore throat and dysphagia
Fever
Drooling
Dysphonia
Neck stiffness: limiting neck ROM (especially hyperextension)
Stridor
May see bulging of the posterior wall of oropharynx on clinical examination
Viral pharyngitis:
-Most pharyngitis cases are viral in origin
-Associated symptoms that are more likely to present with viral illness: cough, nasal congestion, conjunctivitis, hoarseness, diarrhea, oropharyngeal lesions (ulcers or vesicles)
Viruses that are more likely to cause pharyngitis in children:
Common cold (50%): caused by rhinovirus, coronavirus, adenovirus, parainfluenza virus, respiratory syncytial virus.
Influenza (5%): caused by influenza virus (type A & B) most commonly.
Mononucleosis (5%): caused by epstein-barr virus (EBV), cytomegalovirus (CMV)
Viral causes of pharyngitis do not require antibiotic therapy unless there is a secondary bacterial infection.
Streptococcal pharyngitis:
-Strep throat, GABHS pharyngitis
-Infection of pharynx caused by group A beta-hemolytic streptococci (GABHS)
-Most common inn children aged 5-15
-Risk factors: exposure to sick contact with GABHS, winter or early spring
Streptococcal pharyngitis: Typical presentation:
-Acute onset fever and sore throat
-Headache, nausea, vomiting, malaise, dysphagia, abdominal pain
-Cough and rhinorrhea usually absent (presence suggests more viral cause)
-Edema and erythema of tonsils and pharynx; non-adherent tonsillar and/or pharyngeal exudate
-Enlarged and tender anterior cervical lymph nodes
-1 in 10 cases of streptococcal pharyngitis may evolve into scarlet fever: scarlatiniform rash and strawberry tongue
-May have palatine petechiae
Acute rheumatic fever (ARF):
Non-suppurative complications:
Rare in north America:
-more common in children than adolescents and adults
-In Canada 0.1 to 2 cases per 100,000
-Higher in remote, Canadian Indigenous communities (Northern Ontario 8.33/100,000)
-Risk may be higher in immigrants from endemic areas (ex: China, Philippines)
In the USA, 3000-4000 cases of GABHS pharyngitis need to be treated to prevent 1 case of ARF
Can develop 1-4 weeks after GABHS pharyngitis
Cross-reactive antibodies produced in reaction to GABHS infection leading to fever, arthralgia, erythema marginatum, subcutaneous nodules (Osler’s nodes), increased ESR and CRP, carditis, prolonged PR interval, Sydenham’s chorea
Poststreptococcal glomerulonephritis:
Can develop 1-2 weeks after infection with GABHS
Injury to the glomerulus due to deposition of immune complexes and circulating autoantibodies
Pediatric autoimmune neuropsychiatric disorder associated with group A Streptococcal (PANDAS) infection:
Abrupt onset of severe exacerbation of obsessive-compulsive type behaviors or tics in children following GABHS infection
Thought to be due to antibodies cross-reacting with regions in the basal ganglia => behavioral and motor disturbances
Suppurative complications:
Peritonsillar abscess
Retropharyngeal abscess
Otitis media
Sinusitis
Mastoiditis
Cervical Lymphadenitis
Meningitis
Bacteremia
Clinical decision rules:
clinical tool that quantifies the individual contributions that various components of the history, physical examination, and basic laboratory results make toward the diagnosis, prognosis, or likely response to treatment in a patient.
Attempt to formally test, simplify, and increase the accuracy of clinicians’ diagnostic and prognostic assessments.
Existing CDR’s guide clinicians, established pretest probability, provide screening tests for common problems, and estimate risk
The modified centor score:
Mclssac score: the Mclssac Modification of the Centor Score, Adapted Centor Score:
A validated score to help predict the probability of streptococcal pharyngitis and guide clinical decision making
Mclssac modified the score to include age a feature:
-Streptococcal pharyngitis is most common in ages 5-15 years
-It is rare in infants (<3 years) and adults >45 years
Original centor score looked at 4 features:
absence of cough (presence of cough suggest more viral illness), presence of fever, tonsillar exudates, and anterior cervical lymphadenopathy
The modified centor score: Mnemonic:
Must be older than 3 years old
Cough- no cough (+1)
Exudates or swelling-Tonsillar exudates/swelling (+1)
Nodes- anterior cervical adenopathy (+1)
Temperature- Hx of fever or temperature >38 (+1)
Only young-Patients <15 (+1)
Rarely elder-Patients >45 (-1)
Rapid strep test:
Rapid antigen detection test (RADT)
Rapid screen for streptococcal antigens => if positive the patient is treated without follow-up cultures; if negative a throat culture is obtained
Point of care test that can be done in office: rapid turnover time (minutes to 1 hour) compared to throat culture (about 48 hours)
Swab collected from tonsils and posterior pharyngeal wall of patient
Specificity 97%, sensitivity 85%; LR+ 17.2, LR- 0.15
newer nucleic acid tests offer better sensitivity:
-Specificity 99%, sensitivity 92%
-LR+ 92, LR- 0.08
Disadvantages: Rapid point of care testing cannot distinguish between carriers of GABHS and active infection, nor does it indicate antibiotic susceptibility or strain virulence
Throat culture:
Gold standard for diagnosis of streptococcal pharyngitis (10% lower false negative rate)
Swab collected from tonsils and posterior pharyngeal wall of patient
Sample from swab placed on a culture int he lab to observe for bacterial growth
Culture showing growth of streptococcal species confirms the diagnosis
Benefits of antibiotic treatment of GABHS pharyngitis:
-Prevents acute rheumatic fever (NNT=4000)
-decreases the transmission of GABHS
-shortens the illness by 1 to 2 days (NNT=8)
-Reduces symptoms such s headache, sore throat and fever (NNT=6 to reduce symptoms after 3 days of treatment, NNT=21 after 1 week of treatment)
May reduce suppurative complications:
-Subsequent acute otitis media (NNT=29 in children, NNT=145 in adults)
-Subsequent acute sinusitis (NNT=50)
-Subsequent peritonsillar abscess (NNT=27)
Most cases are self-limiting in _____ days even without antibiotics.
7-10
harms of antibiotic treatment of GABHS pharyngitis:
Shortens the illness by 1 to 2 days but no difference in time off school or work
Has not shown to decrease risk of poststreptococcal glomerulonephritis or subsequent meningitis
Harms of antibiotic treatment in general:
Mild reactions: diarrhea, vomiting, abdominal pain, rash (NNH=10)
Severe reactions: Clostridium difficile-associated diarrhea
Life-threatening reactions: anaphylactic shock, sudden cardiac death
Considerations for antibiotic therapy:
-Mant international guidelines consider GABHS pharyngitis self-limiting and do not recommend antibiotic treatment
-Delayed prescriptions decrease antibiotic use with no significant effect on symptom duration or clinical treatment
-Populations with a higher incidence of GABHS complications, such as indigenous people of Canada, might be more likely to benefit from antibiotic treatment
-Children are at greater risk of complications (ex: otitis media, peritonsillar abscess, rheumatic fever), may initiate antibiotic therapy sooner
-Carriers of GABHS do not require treatment: at least 30% of GABHS cultured in primary care are due to carriers who are not sick and are at very low risk of infecting other people
Most cases are self-limiting in 7-10 days even without antibiotics, but Canadian guidelines suggest a full ______course of antibiotic therapy for confirmed GABHS infection.
10-day
For those with high likelihood of strep throat (score of 4 or more) with no signs of complications, a reasonable approach is watchful waiting and delayed prescription for antibiotics while waiting for culture results:
Advise patient to monitor symptoms and only fill the antibiotic prescription after confirmation of positive throat culture.
Another approach: empirical antibiotic therapy while waiting for throat culture results (and stop antibiotics in the culture is negative)
Antibiotic therapy of choice:
Penicillin (unless patient has allergy)
-5 day course of antibiotic therapy as clinically effective as 10 day course, although it might be less effective in eradicating GABHS infection
-Antibiotic therapy started within 9 days of symptom onset in confirmed GABHS will prevent rheumatic fever
If the likelihood of streptococcal infection is low (ex: modified centor score of 1 or less) or culture is negative, viral pharyngitis is likely.
Provide supportive therapies and symptomatic relief:
-Analgesics (NSAIDs, acetaminophen, topical anesthetics)
-Throat lozenges or sprays
-Warm soothing drinks/liquids
-Gargle/rinse
Infectious Mononucleosis:
mono or “kissing disease”
Infection usually caused by Epstein-Barr virus (EBV)- more than 90% of cases
Most common in ages 5-25 years
Typical presentation of mononucleosis:
-Gradual onset, low grade fever, sore throat
-Malaise, fatigue
-Tonsillar exudates
-Palatine petechiae
-Lymphadenopathy (especially posterior cervical lymph nodes)
-Splenomegaly (50% of cases) => splenic rupture is an uncommon complication (0.1-0.5%)-highest risk in first 3 weeks of illness
Monospot test:
Rapid screening test that detects heterophil antibody agglutination
Best initial test for diagnosis of EBV infection- fast, inexpensive, has high specificity
-Can be conducted in-office
-Sensitivity 82%, specificity 99%
-LR+82, LR- 0.18
