Week 3: Infections of the pharynx

Question 1

Upper respiratory tract defenses

Answer 1

• nasal hairs filter larger particles
• epiglottis prevents aspiration
• air humidification and mucociliary clearance
• saliva production in mouth
• IgA in secretions, IgG in saliva and mucous
• Waldeyer’s ring: adenoids, palatine, lingual, tubal tonsils

Question 2

Pharyngitis diagnosis

Answer 2

• Herpangina due to Cox-Sackie: many small vesicles in posterior pharynx
• Adenovirus: Pharyngoconjuntival fever
• Group A strep or EBV: erythema/exudate
• EBV/CMV: lymphadenopathy

Question 3

Diagnosis of viral upper respiratory infections

Answer 3

• rhinovirus: rhinitis without fever of malaise
• parainfluenza: croup
• adenovirus: conjunctivitis

Question 4

Sinusitis

Answer 4

• risks: septum deviation, atopic disease, immunodeficiency
• acute sinusitis: can result from URI causing obstruction of drainage due to decreased mucociliary clearance and swelling of ostia. <3 weeks
• etiology: S. pneumoniae, H. influenzae, Moraxella catarrhalis, S. aureas, S. pyogenes
• symptoms: facial pain, fever, purulent drainage, funny smell/taste, post nasal drip
• Rx: sinus irrigation, analgesics, decongestions. Antibacterial when bacteria suspected. corticosteroids.

Question 5

Complications of sinusitis

Answer 5

• allergic complications-asthma exacerbation
• erosion of infected material under high pressure through bony walls into adjacent structures and spaces, causing orbital cellulitis, subdural empyema, Potts puffy tumor, brain abscess
• Pott’s puffy tumor: subperiosteal abscess assoc. with osteomyelitis

Question 6

Otitis Media

Answer 6

• disease of early childhood: 6mos.-2years
• boys, caucasians, native americans and eskimos
• pathophysiology: organisms entering through auditory tube, may be due to impairment of mucociliary clearance due to obstruction or mechanism problem
• microbiology: S. pneumoniae, H. influenza, Moraxella catarrhalis
• Rx: not always needed. Treat younger children<6 months. Rx with high dose amoxicillin, cephalosporins, azithromycin, or other macrolides.
• complications: hearling loss, learning problems, chronic suppurative otitis media, mastoiditis, brain access, bacterium, meningitis, lateral sinus thrombosis

Question 7

Herpangina

Answer 7

• usually due to Coxsackie viruses A and B and echovirus
• usually in young children and characterized by sudden fever, malaise, dysphagia, refusal to eat
• 1-2mm vesicles, surrounded by erythema, painful. in posterior oropharynx. Ulcerate to form yellow grayish ulcers.

Question 8

Strep throat

Answer 8

• Streptococcus pyogenes: group A beta hemolytic strep (GAS)
• M protein: virulent factor
• pharyngeal pain, fever, usually no rhinorrhea and cough
• dx: rapid antigen test, but lacks sensitivity

Question 9

Scarlet fever

Answer 9

• erythematous sandpaper rash associated with GAS infection
• the rash blanches
• usually due to pharyngitis but can be caused by other processes
• strawberry tongue, circumoral palor, Pastia’s lines
• caused by street erythrogenic toxin
• usually has benign course

Question 10

Peritonsillar infection

Answer 10

• Quinsy: abscess in peritonsillar tissue
• sometimes only swelling initially with no abscess
• adolescence
• peritonsilar swelling, edema, deviation of uvula, hot potato voice, truisms, inability to completely open mouth due to spasm or paralysis of muscles of mastication
• agents: strep pyogenes, strep viridans, staph aureus, oral anaerobes
• Rx incision and drainage with CLindamycin and ampicillin aulbactam

Question 11

Parapharyngeal and retropharyngeal infections

Answer 11

• deeper than peritonsilar abscesses, but is similar
• younger children
• can track along deep neck spaces or even down to thorax
• surgery for decompression is usually necessary because may impinge upon airway
• antibacterials to cover staph bureaus, strep pyogenes, viridans, anaerobes

Question 12

Lemierre’s syndrome

Answer 12

• septic jugular thrombophlebitis associated with pharyngotonsillitis
• bacteria cross from pharynx into perivascular space
• fever, pain, erythema, tenderness, swelling, septic emboli
• agent: Fusobacterium necrophorum: anaerobic fusiform gram negative rod
• high morbidity and mortality without treatment

Question 13

Corynebacterium diphtheriae

Answer 13

• Gram + bacillus
• highly contagious and requires stick contact and respiratory isolation
• virulence: production of an exotoxin which inhibits RNA translocate causing tissue necrosis
• shallow ulcers with grayish membrane in cuteness form
• myocardiopathy causes most deaths
• dx: clinical suspicion

Question 14

Croup

Answer 14

• laryngotracheobronchitis: inflammation of larynx and associated structures
• caused by viral URI, usually parainfluenza 1 and 2
• swelling causes airway narrowing
• barky cough and striders breathing that may be associated with fever
• supportive treatment, cool mist, racemic epinephrine and oxygen
• single dose dexamethasone in ER

Question 15

Epiglottitis

Answer 15

• infection and swelling of the epiglottis
• sudden airway obstruction, is a respiratory emergency
• don’t insert tongue blade, may cause arrest
• H. influenza type B used to be major cause, but now has vaccine
• agents: s. aureas, S. pneumoniae