Retropharyngeal Abscess

Epidemiology and Etiology

Epidemiology

• Most common in children < 5 years of age
• Less common in adults (due to regression Regression Corneal Abrasions, Erosion, and Ulcers of the retropharyngeal lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs nodes)
• More common in males than females

Etiology

• Abscesses occur due to infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease that drain to lateral retropharyngeal lymph Lymph The interstitial fluid that is in the lymphatic system. Secondary Lymphatic Organs nodes.
• May be secondary to: 
  • Upper respiratory tract infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease (more common in children) 
  • Otitis media
  • Sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis
  • Pharyngeal trauma (more common in adults) 
    • Foreign body Foreign Body Foreign Body Aspiration (e.g., fishbone)
    • Endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD)
    • Dental procedures
• Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are often polymicrobial and may include: 
  • Aerobes
    • Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus aureus 
    • Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus pyogenes
  • Anaerobes Anaerobes Lincosamides 
    • Bacteroides Bacteroides Bacteroides is a genus of opportunistic, anaerobic, gram-negative bacilli. Bacteroides fragilis is the most common species involved in human disease and is part of the normal flora of the large intestine. Bacteroides 
    • Fusobacteria Fusobacteria A genus of gram-negative, anaerobic, rod-shaped bacteria found in cavities of humans and other animals. No endospores are formed. Some species are pathogenic and occur in various purulent or gangrenous infections. Perianal and Perirectal Abscess

Clinical Presentation

Early symptoms

• May mimic pharyngitis Pharyngitis Pharyngitis is an inflammation of the back of the throat (pharynx). Pharyngitis is usually caused by an upper respiratory tract infection, which is viral in most cases. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, and hoarseness. Pharyngitis
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Sore throat Throat The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx: Anatomy
  • Pharyngeal erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion
• Dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming “stuck.” Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia
• Odynophagia Odynophagia Epiglottitis
• Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess stiffness/ asymmetry Asymmetry Examination of the Upper Limbs 
• Trismus Trismus Spasmodic contraction of the masseter muscle resulting in forceful jaw closure. This may be seen with a variety of diseases, including tetanus, as a complication of radiation therapy, trauma, or in association with neoplastic conditions. Tetanus ( lockjaw Lockjaw Spasmodic contraction of the masseter muscle resulting in forceful jaw closure. This may be seen with a variety of diseases, including tetanus, as a complication of radiation therapy, trauma, or in association with neoplastic conditions. Tetanus)

Later symptoms

• Ill-appearing, drooling
• “Sniffing” position: leaning forward with neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess extended
• Respiratory distress: 
  • Tachypnea Tachypnea Increased respiratory rate. Pulmonary Examination 
  • Stridor Stridor Laryngomalacia and Tracheomalacia
  • Nasal flaring
  • Subcostal retractions Subcostal retractions Respiratory Syncytial Virus

Diagnosis and Management

Diagnosis

• Initial work-up includes:
  • CBC
  • Blood culture
• Diagnosis is confirmed by imaging.
  • Lateral neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
    • Widened retropharyngeal space 
    • Gas in the retropharyngeal space
  • Computed tomography (CT) of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess with contrast (gold standard):
    • Rim-enhancing hypodense collection in retropharyngeal space
    • Thickening of the prevertebral space 
    • Presence of air or air-fluid levels

Management

• The 1st and most important step is protecting the airway Airway ABCDE Assessment → intubation Intubation Peritonsillar Abscess if needed! 
• Surgical drainage
• Antibiotics
  • Ampicillin Ampicillin Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic. Penicillins/ sulbactam Sulbactam A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone. Cephalosporins or clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides
  • If no response, vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides or linezolid Linezolid An oxazolidinone and acetamide derived anti-bacterial agent and protein synthesis inhibitor that is used in the treatment of gram-positive bacterial infections of the skin and respiratory tract. Oxazolidinones
  • When clinically improved, may switch to amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins/clavulanate or clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides (with oral linezolid Linezolid An oxazolidinone and acetamide derived anti-bacterial agent and protein synthesis inhibitor that is used in the treatment of gram-positive bacterial infections of the skin and respiratory tract. Oxazolidinones for MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus coverage).

Complications

Retropharyngeal abscesses are considered the most deadly deep neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess infection. 

The most common complications include:

• Mediastinitis Mediastinitis Mediastinitis refers to an infection or inflammation involving the mediastinum (a region in the thoracic cavity containing the heart, thymus gland, portions of the esophagus, and trachea). Acute mediastinitis can be caused by bacterial infection due to direct contamination, hematogenous or lymphatic spread, or extension of infection from nearby structures. Mediastinitis
  • Occurs due to extension Extension Examination of the Upper Limbs into the posterior mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels: Anatomy through the “danger space” → space that allows direct spread to the thorax
  • Can progress to acute necrotizing mediastinitis Mediastinitis Mediastinitis refers to an infection or inflammation involving the mediastinum (a region in the thoracic cavity containing the heart, thymus gland, portions of the esophagus, and trachea). Acute mediastinitis can be caused by bacterial infection due to direct contamination, hematogenous or lymphatic spread, or extension of infection from nearby structures. Mediastinitis
  • Mortality rate Mortality rate Calculated as the ratio of the total number of people who die due to all causes over a specific time period to the total number of people in the selected population. Measures of Health Status of 50%
• Internal jugular vein Internal jugular vein Parapharyngeal Abscess thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus 
• Carotid artery rupture → due to extension Extension Examination of the Upper Limbs of the carotid sheath
• Airway obstruction Airway obstruction Airway obstruction is a partial or complete blockage of the airways that impedes airflow. An airway obstruction can be classified as upper, central, or lower depending on location. Lower airway obstruction (LAO) is usually a manifestation of chronic disease, such as asthma or chronic obstructive pulmonary disease (COPD). Airway Obstruction
• Septicemia
• Epidural abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease or diskitis

Differential Diagnosis

• Epiglottitis: an inflammation of the epiglottis most commonly caused by infection with Haemophilus influenzae. Epiglottitis presents with “cherry-red” epiglottis, fever, dysphagia, drooling, and difficulty breathing. The condition is commonly seen in unvaccinated children. Treatment is with rocephin and steroids.
• Peritonsillar abscess: a bacterial infection (most commonly S. pyogenes) that causes an abscess next to the palatine tonsils. The condition is more common in children and young adults and presents with trismus, fever, and sore throat, with a “hot potato” voice. Physical exam shows an abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease near the pharyngeal tonsil causing uvula Uvula A fleshy extension at the back of the soft palate that hangs above the opening of the throat. Peritonsillar Abscess deviation. Treatment is with antibiotics and surgical drainage. 
• Parapharyngeal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease or prevertebral space infection: very similar clinical presentation to retropharyngeal abscesses but most often caused by dental infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease that extend into the lateral or posterior pharyngeal space. The best way to differentiate pharyngeal from retropharyngeal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease is by CT of the neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess. Treatment is with antibiotics and surgical drainage. 
• Meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis: an infection of the meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges: Anatomy, the protective membranes around the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification, most often caused by Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus pneumoniae or H. influenzae H. influenzae A species of Haemophilus found on the mucous membranes of humans and a variety of animals. The species is further divided into biotypes I through VIII. Haemophilus. Meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis presents with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, stiff neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, and headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess. The condition is differentiated from retropharyngeal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease by the presence of light sensitivity, headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess, and nuchal rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon. Diagnosis is by lumbar puncture Lumbar Puncture Febrile Infant for cerebrospinal (CSF) evaluation. Treatment consists of the rapid administration of antibiotics.