L11 Upper Respiratory Infections Flashcards
Virology of Common Cold
Mostly rhinovirus (parainfluenza virus and respiratory syncytial virus seen in peds)
Main presentation of Common Cold
Rhinorrhea, nasal congestion
Other symptoms of Common Cold
Sore throat, non-productive cough, malaise/mild headache, low-grade fever (all usually resolving in 3-10 days), nasal mucosal swelling, nasal discharge (clear, watery, purulent), +/- conjunctival infection, no pulmonary findings or adenopathy
What is not useful in the treatment of common cold?
Antibiotics will not help
Treatment of common cold
Fluids/rest etc, analgesics (acetominophen, NSAIDs), topical analgesics for sore throat (chloraseptic/sucrets), antihistamine/decongestant combo, expectorants/antitussives (guaifenesin separate or with dextromethorphan for cough)
Specific drugs for common cold
Acetominophen, NSAIDs, Chloraseptic, Sucrets, Guaifenesin (Robitussin), Guaifenesin with dextromethorphan (Robitussin DM)
Main presentation of Influenza
Abrupt onset, fever (can be very high), myalgia, sore throat (can be severe)
Other symptoms of influenza
Chills, malaise, headache, cough (usually non-productive), nasal discharge +/-, flushing, hot/dry skin, unremarkable posterior pharynx, mild cervical LAD, negative chest exam
High risk groups for Influenza
Adults >65, children <5 (mostly <2), chronic illnesses/asthma/cardiac/DM/renal or liver disease, immunosuppression (glucocorticoids, HIV/AIDS), pregnant women or post partum (within 2 wks), healthcare workers, residents of nursing homes, Native Americans, BMI >40
Outpatients who should be tested for Influenza during the season
- Immunocompetent with fever/respiratory symptoms after hospital admission regardless of onset
- Immunocompetent but high risk patients presenting within 5 days of illness onset
- Immunocompromised patients with acute febrile respiratory illness or community acquired pneumonia regardless of of onset
Inpatients who should be tested for Influenza during the season
Any patient with acute febrile respiratory illness, regardless of time of illness onset
When should diagnostic testing be done for Influenza
Within first 3-4 days of illness
Rapid Antigen Tests (RAT)
Nasal pharyngeal aspirate/swab and wait 15 minutes for results, some can distinguish type A/B, screening test
Immunofluorescence
Nasal swab/washing, 1-4 hours for results, can differentiate types A/B, screening test
Rapid Molecular Assay
NP swab and 15-30 minutes for results, higher sensitivity and specificity because distinguishes type A/B, currently limited availability
RT-PCR
NP swab/sputum and 1-8 hours for results, MOST sensitive and specific, used when you want an influenza type and subtype
Viral cultures
Viral tissue cell cultures come back in about 3-10 days, GOLD standard for lab diagnosis, not for initial clinical management but for confirming a screening
Reasons to order RT-PCR or viral culture for Influenza
- Negative RAT or immunoflorescent antibody staining screening test but community influenza rates are high
- Positive RAT or immunoflorescent antibody staining screening test but community influenza rates are low (test if vaccine is right in the first cases)
- Patient has recent exposure to pigs/poultry and there is worry for novel influenza A virus
Indications for antiviral treatment of Influenza
Illness requiring hospitalization, progressive/severe/ complicated illness, high risk for complications
What is the timeline for antiviral treatment of influenza?
Must be within 24-30 hours of onset of symptoms
Antiviral medication for influenza
Prophylaxis for at risk groups within 30 hours can reduce symptoms, tends to shorten course by 1-2 days
Type of antiviral drug used for influenza A/B
Neuraminidase inhibitors
Types of neuraminidase inhibitors used for influenza
- Oseltamivir (Tamiflu)- 75 mg po bid x 5 days
- Zanamivir (Relenza)- 10 mg (2 inhalations) bid x 5 days
- Peramivir (Rapivab)- 600 mg IV x 1
When would you use neuraminidase inhibitors in a pregnant patient?
They are Category C but if confirmed, probable or suspected influenza A during the pregnancy
Contraindications of Zanamivir
Patients with asthma/chronic respiratory conditions
Complications of influenza
Pneumonia, rhinosinusitis, otitis media, myositis/rhabdomyolysis, CNS involvement, cardiac complications
Influenza vaccines
- Trivalent inactivated vaccine (A H1N1, A H3N2 and influenza B) given IM
- Quadrivalent (protections against additional influenza B virus) given IM
What influenza vaccine do you use in people 18-49?
Standard dose inactivated influenza vaccine (trivalent or quadrivalent), injectible
What influenza vaccine do you use in people >65?
High dose trivalent inactivated influenza vaccine, injectable
LAIV4
Live attenuated vaccine reintroduced this year, intranasal, recommended ages 2-49
Contraindications of influenza vaccine
Current moderate to severe illness (fever), hx of guillain-barre syndrome within 6 wks of previous vaccine, hx of allergic rxn
What is seen in the flu but not the common cold?
Fever with acute onset, headache, myalgias, fatigue/weakness, severe sore throat, cough that is more than moderate (hacking seen in cold)
Common viral causes of pharyngitis
Rhinovirus, adenovirus (not usually with pharyngeal exudate), parainfluenza, influenza
Presentation of pharyngitis caused by HSV
Vesicles on an erythematous base, culture it with Tzanck prep
Presentation of mononucleosis (viral pharyngitis)
Sore throat, pharyngeal erythema, tonsillar exudates, enlarged cervical lymph nodes of diffuse LAD, splenomegaly (50%), duration 2-4 wks (contagious up to 3 months)
Diagnostic studies for mononucleosis
Monospot, CBC with diff (see increased atypical lymphocytes)
Presentation of acute retroviral syndrome (viral pharyngitis)
Acute gingivitis, painful oropharyngeal ulceration (sharply demarcated), febrile illness like mononucleosis with painless, generalized LAD, no tonsillar enlargement or pharyngeal exudates, generalized maculopapular rash, fatigue
What can often be the first manifestation of an HIV infection?
Acute retroviral syndrome
Tx of viral pharyngitis
Hydration, antipyretics/analgesics, “magic mouthwash”
Tx for HSV
Acyclovir, famciclovir
Bacteria associated with pharyngitis
Group A streptococcus (GAS), C. trachomatis, N. gonorrhea, M. pneumoniae, H. influenza, C. diphtheriae
Presentation of diphtheria
Gray exudate tight adherent to throat and nasal passageway
Symptoms of streptococcal pharyngitis
Sore throat, odynophagia, fever/malaise/anorexia, arthralgias/myalgias, nausea/vomiting, neck discomfort from swollen glands
Signs of streptococcal pharyngitis
Pharyngeal erythema, tonsillar hypertrophy, purulent exudate, tender/enlarged anterior cervical lymphnodes, palatal petechiae (CLASSIC SIGN)
Centor criteria for streptococcal pharyngitis
Patients with 3 of 4 should undergo testing for GAS
1. Tonsillar exudates
2. Tender anterior cervical adenopathy
3. Fever by history
4. Absence of cough
If patient meets criteria but negative RADT, treat empirically while waiting for culture
Gold standard for diagnosis of pharyngitis
Throat culture (can be bacterial or viral)
First line therapy for adult GAS pharyngitis
- Penicillin V 500 mg po TID x 10 days
- Amoxicillin 500 mg BID x 10 days
- Penicillin G benzathine (Bicillin L-A) 1.2 million units IM single dose (if think ppl wont follow up)
- Cephalexin 500 mg PO BID x 10 days
Tx for streptococcal pharyngitis when the patient has a penicillin allergy
- Azithromycin 500 mg po day 1 followed by 250 mg po days 2-5 (Z pack)
- Clindamycin 300 mg po tid x 10 days
- Clarithromycin 250 mg bid x 10 days
* don’t forget supportive care (lozenges, NSAIDs, acetaminophen)
Complications of streptococcal pharyngitis
Acute rheumatic fever (in immunosuppressed patients), post-streptococcal glomerulonephritis, peritonsillar abscess, otitis media, rhinosinusitis, bacteremia, pneumonia, strep toxic shock syndrome, scarlet fever
Symptoms of scarlet fever
Maculopapular rash (feels like sand paper-starts on trunk), desquamation, Pastia’s lines, facial flushing with circumoral pallor and strawberry tongue (***scarlet fever can predispose for acute rheumatic fever)
Pastia’s lines
Scarlet lines in the antecubital fossa
Cause of scarlet fever
Reaction to pyrogenic toxin of bacteria
Etiology of peritonsillar abscess
Polymicrobial, mostly S pyogenes (GAS), S aureus (including MRSA), mixed respiratory anaerobes and sometimes H. influenzae
Cellulitis in the oral cavity
Infection and inflammation of tissue between palatine tonsil capsule and pharyngeal muscles, no discrete pus collection
Description of peritonsillar abscess
Collection of pus between capsule of tonsil and pharyngeal muscles, usually progression of cellulitis
Symptoms of peritonsillar abscess
Severe sore throat (unilateral), drooling, trismus, fever, ipsilateral neck or ear pain, fatigue, irritability
Trismus
Spasm of internal pterygoid muscle in peritonsillar abscess, causing lock jaw
Signs of peritonsillar abscess
Swelling pushing tonsil with deviation of uvula to opposite side, fullness of posterior soft palate with palpable fluctuance, cervical LAD, “hot potato voice”
How to distinguish cellulitis from abscess
CT with IV contrast (spread of infection to parapharyngeal space, or if PE is limited due to trismus)
Labs for peritonsillar abscess
CBC, electrolytes, throat culture, culture and gram stain of abscess fluid if aspirated
Antimicrobial therapy for peritonsillar abscess
Parenteral: ampicillin-sulbactam (Unasyn) or clindamycin (vancomycin if MRSA)
Oral: amoxicillin-clavulanate (Augmentin) or clindamycin x 14 days
Etiology of epiglottitis
H. influenzae
Symptoms of epiglottitis
Drooling, stridor, severe sore throat, no cough, toxic appearance (no URI symptoms)
Imaging for epiglottitis
Lateral neck x-ray with “Thumb sign”, CT/MRI
Etiology of severe tonsillopharyngitis
EBV, HSV 1 or 2, coxsackie virus, adenovirus, c. diphtheria, N. gonorrhea
Presentation of severe tonsillopharyngitis
Pharyngeal edema, exudates, tonsillar hypertrophy
How to diagnose severe tonsillopharyngitis
Monospot, viral/bacterial cultures, CT or MRI with contrast
Causes of retropharyngeal abscess or cellulitis
Trauma (like chicken bone), recent instrumentation with secondary bacterial infection (Ex. tonsillectomy)
Cause of submandibular space infection (Ludwig’s angina)
Often due to odontogenic infection (from a tooth)
Distinctive sign of submandibular space infection (Ludwig’s angina)
“Woody” indurated submandibular area with possible crepitus
Most common infectious etiology of laryngitis
Viruses associated w/ URI (bacteria can be streptococci, moraxella catarrhalis or H. influenzae)
Key symptom of laryngitis
Hoarseness (can also have dysphonia (variation in vocal quality) or URI symptoms
Rhinosinusitis (ARS) (sinus infection)
Purulent nasal drainage AND nasal obstruction and/or facial pain, pressure or fullness
Acute vs subacute vs chronic rhinosinusitis
Acute: symptoms less than 4 weeks
Subacute: symptoms for 4-12 weeks
Chronic: symptoms longer than 12 weeks
Recurrent acute rhinosinusitis
4 or more episodes or ARS per year
Most common etiology for acute viral rhinosinusitis
rhinovirus, influenza or parainfluenza
Symptoms of acute viral rhinosinusitis
Low grade fever, nasal congestion/discharge, facial pain/pressure, fatigue, cough, maxillary tooth discomfort, ear pressure/fullness, headache
Signs of acute viral rhinosinusitis
Purulent drainage in nose or posterior pharynx, nasal mucosal edema, edema in facial area, tenderness ot percussion of upper teeth, sinus tenderness, may be able to use transillumination to see opacity
Acute viral sinusitis dx
Clinical, less than 10 days of symptoms consistent with ARS that are not worsening and progressively getting better
What are plain sinus films used for?
Acute viral sinusitis
May show sinus fluid levels/poor detecting mucosal thickening, inability to distinguish polyps/masses from fluid/edema
Treatment during days 1-9 of acute viral sinusitis
Analgesics, saline irrigation, mucolytics, intranasal decongestants, intranasal glucocorticoids
Pathophysiology of acute bacterial sinusitis
Prior history of a URI and AVRS (secondary bacterial infection to viral infection), decreased drainage of thick secretions leads to obstruction of sinus ostia and entrapment of bacteria leads to infection
Guidelines for diagnosis of acute bacterial sinusitis
Persistent symptoms lasting longer than 10 days with no clinical improvement
OR
Onset with severe symptoms (fever over 102, purulent nasal discharge, facial pain at least 3-4 consecutive says at onset
OR
viral URI lasted 5-6 days and was improving followed by double worsening and severe symptoms
Patients at high risk for antibiotic resistance
Over 65 years Severe infection with fever over 102 Recent hospitalization Immunocompromised Comorbidities Recent antimicrobial use in last month
First line antimicrobial treatment of ABRS that is not at high risk for resistance
- Amoxicillin-clavulanate (Augmentin) 500/125 mg TID or 875/125 mg BID
- Penicillin allergy:
Doxyxycline 100 mg BID
Levofloxacin (Levaquin) 500 mg qd
Moxifloxacin (Avelox) 400 mg qd
5-7 days!
When do you move to second-line antimicrobial meds for ABRS?
If no response or worsening symptoms after 7 days of empiric antibiotic tx or high risk of antibiotic resistance
Second line antimicrobial treatment of ABRS
- Amoxicillin-clavulanate (Augmentin) 2000 mg/ 125 mg BID
- Penicillin allergy:
Levofloxacin (Levaquin) 500 mg qd
Moxifloxacin (Avelox) 400 mg qd
Doxyxycline 100 mg BID
7-10 days!
What is complicated acute bacterial sinusitis?
Spread of the infection to the CNS, orbits or surrounding tissues
Symptoms of complicated ABRS
Osteomyelitis (frontal, doughy edema; sever HA), meningitis/brain abscess/epidural abscess (severe HA, altered mental status, +/- nuchal rigidity), periorbital and/or preseptal or orbital cellulitis (periorbtal edema/erythema, abnormal EOM, proptosis, vision changes), may have high fever >102
Studies used to diagnose complicated ABRS
CT scan with contrast, MRI if suspected extra sinus involvement, sinus aspirate culture; ADMIT TO HOSPITAL; URGENT ENT/ID CONSULT
Gold standard for diagnosis of complicated ABRS
Sinus aspirate culture
Chronic rhinosinusitis risk factors
Allergic rhinitis, chronic exposure to environmental irritants, defects in mucociliary clearance, immune deficiency, anatomical abnormalities predisposing to sinus obstruction, latrogenic (multiple sinus surgeries)
4 cardinal symptoms of CRS in adults (what is the 4th symptom in children?)
Mucopurulent nasal drainage
Nasal obstruction and congestion
Facial pain, pressure and fullness
Reduction/loss of sense of smell (ethmoid sinuses)
* in kids is is cough instead of disturbance of smell
Diagnostic criteria of CRS
Presence or at least 2 of 4 cardinal symptoms
AND
Infection lasting longer than 12 weeks with medical management
PLUS
Sinus mucosal disease with imaging (CT) with mucosal thickening or partial/complete opacification of paranasal sinuses
OR
Direct visualization (nasal endoscopy) of mucosal inflammation, polyps and/or purulent mucus and edema
Diagnosis of CRS
Non-contrast CT (because want to see anatomical abnormalities); refer to ENT (nasal endoscopy and sinus aspirate culture)
Treatment of CRS
Nasal saline lavage, intranasal corticosteroids, oral corticosteroids, oral antimicrobials, antihistamines, topical/systemic antifungals, endoscopic sinus surgery
Sx of retropharyngeal abscess or cellulitis
neck stiffness, minimal peritonsilar findings; trismus uncommon; VERY SERIOUS- can extend to mediastinum
Dx/tx for retropharyngeal abscess
CT/MRI w/ contrast, airway management, abx, image guided aspiration of abscess
Sx. of submandibular space infection
swelling, stiff neck, drooling, often unable to talk, “woody” sign w/ possible crepitus (indurated)
Tx for submandibular space infection
CT/MRI w/ contrast, airway management, abscess drainage, abx
Non-infectious causes of laryngitis
vocal abuse, intubation, toxic exposure (smoke inhalation, radiation), GERD, vocal cord nodules or polyps, carcinoma of vocal cords, neuro dysfunciton
Dx of laryngitis
Hx and PE; hoarseness >2 weeks w/o URI sx requires ENT referral for laryngoscopy (especially w/ hx of tobacco or alcohol use); hoarseness from URI can last 2-3 weeks
Signs of laryngitis
erythem, edema, vascular engorgement, nodules or ulcerations of vocal cords
Tx of laryngitis
remove offending agent, voice rest, humidification, increase fluids, stop smoking, refer to ENT prn, no need for abx unless bacterial infection
Who is at increased risk for rhinosinusitis
females; ages 45-64
Etiology of Acute bacterial rhinosinusitis (ABRS) (only 0.5-2%)
strep pneumoniae, H. influenzae, moraxella catarrhalis
