Jump to content

Laryngitis: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
m Journal cites:, added 1 DOI using AWB (12130)
Line 32: Line 32:


<!-- Treatment and epidemiology -->
<!-- Treatment and epidemiology -->
The acute form generally gets better on its own.<!-- <ref name=BMJ2014/> --> Resting the voice and sufficient fluids may help.<ref name=BMJ2014/> [[Antibiotic]]s generally do not appear to be useful in the acute form.<ref name=Rev2015>{{cite journal|last1=Reveiz|first1=L|last2=Cardona|first2=AF|title=Antibiotics for acute laryngitis in adults.|journal=The Cochrane database of systematic reviews|date=23 May 2015|volume=5|pages=CD004783|pmid=26002823|doi=10.1002/14651858.CD004783.pub5}}</ref> The acute form is common while the chronic form is not.<ref name=BMJ2014/> The chronic form occurs most often in middle age and is more common in men than women.<ref name=Dh2014>{{cite book|last1=Dhingra|first1=P. L.|last2=Dhingra|first2=Shruti|title=Diseases of Ear, Nose and Throat|date=2014|publisher=Elsevier Health Sciences|isbn=9788131236932|page=292|edition=6|url=https://books.google.ca/books?id=0ByMBgAAQBAJ&pg=PA292|language=en}}</ref>
The acute form generally gets better on its own.<!-- <ref name=BMJ2014/> --> Resting the voice and sufficient fluids may help.<ref name=BMJ2014/> [[Antibiotic]]s generally do not appear to be useful in the acute form.<ref name=Rev2015>{{cite journal|last1=Reveiz|first1=L|last2=Cardona|first2=AF|title=Antibiotics for acute laryngitis in adults|journal=The Cochrane database of systematic reviews|date=23 May 2015|volume=5|issue=5|pages=CD004783|pmid=26002823|doi=10.1002/14651858.CD004783.pub5}}</ref> The acute form is common while the chronic form is not.<ref name=BMJ2014/> The chronic form occurs most often in middle age and is more common in men than women.<ref name=Dh2014>{{cite book|last1=Dhingra|first1=P. L.|last2=Dhingra|first2=Shruti|title=Diseases of Ear, Nose and Throat|date=2014|publisher=Elsevier Health Sciences|isbn=9788131236932|page=292|edition=6|url=https://books.google.ca/books?id=0ByMBgAAQBAJ&pg=PA292|language=en}}</ref>
{{TOC limit|3}}
{{TOC limit|3}}


Line 52: Line 52:


=== Voice quality ===
=== Voice quality ===
Aside from a hoarse-sounding voice, changes to pitch and volume may occur with laryngitis. Speakers may experience a lower or higher pitch than normal, depending on whether their vocal folds are swollen or stiff.<ref name=BMJ2014/><ref>{{Cite journal|last=Takahashi|first=H.|last2=Koike|first2=Y.|date=1976|title=Some perceptual dimensions and acoustical correlates of pathologic voices|journal=Acta Oto-laryngologica Supplementum|volume=|issue=338|pages=1–24}}</ref> They may also have breathier voices, as more air flows through the space between the vocal folds (the [[glottis]]), quieter volume<ref>{{Cite journal|last=Shipp|first=Thomas|last2=Huntington|first2=Dorothy A.|date=1965-11-01|title=Some Acoustic and Perceptual Factors in Acute-Laryngitic Hoarseness|url=http://jshd.pubs.asha.org/article.aspx?doi=10.1044/jshd.3004.350|journal=Journal of Speech and Hearing Disorders|volume=30|issue=4|doi=10.1044/jshd.3004.350|issn=0022-4677|pages=350}}</ref> and a reduced range.<ref name="BMJ2014"/><ref name="BMJ2014"/>
Aside from a hoarse-sounding voice, changes to pitch and volume may occur with laryngitis. Speakers may experience a lower or higher pitch than normal, depending on whether their vocal folds are swollen or stiff.<ref name=BMJ2014/><ref>{{Cite journal|last=Takahashi|first=H.|last2=Koike|first2=Y.|date=1976|title=Some perceptual dimensions and acoustical correlates of pathologic voices|journal=Acta Oto-laryngologica Supplementum|volume=|issue=338|pages=1–24}}</ref> They may also have breathier voices, as more air flows through the space between the vocal folds (the [[glottis]]), quieter volume<ref>{{Cite journal|last=Shipp|first=Thomas|last2=Huntington|first2=Dorothy A.|date=1965-11-01|title=Some Acoustic and Perceptual Factors in Acute-Laryngitic Hoarseness|url=http://jshd.pubs.asha.org/article.aspx?doi=10.1044/jshd.3004.350|journal=Journal of Speech and Hearing Disorders|volume=30|issue=4|doi=10.1044/jshd.3004.350|pmid=5835492|issn=0022-4677|pages=350}}</ref> and a reduced range.<ref name="BMJ2014"/><ref name="BMJ2014"/>


==Causes==
==Causes==
Line 75: Line 75:


==== Allergies ====
==== Allergies ====
* Findings are unclear as to whether asthma may cause symptoms commonly associated with laryngitis.<ref name="BMJ2014" /> Some researchers have posited that allergic causes of laryngitis are often misdiagnosed as being the result of acid reflux.<ref>{{Cite journal|last=Brook|first=Christopher|last2=Platt|first2=Michael|last3=Reese|first3=Stephen|last4=Noordzij|first4=Pieter|date=January 2016|title=Utility of Allergy Testing in Patients with Chronic Laryngopharyngeal Symptoms: Is It Allergic Laryngitis?|url=http://oto.sagepub.com.proxy3.library.mcgill.ca/content/154/1/41.full.pdf+html|journal=Otolaryngoly - Head Neck Surgery|publisher=|volume= 154| issue = 1 41-45|doi=10.1177/0194599815607850|pages=41–45}}</ref>
* Findings are unclear as to whether asthma may cause symptoms commonly associated with laryngitis.<ref name="BMJ2014" /> Some researchers have posited that allergic causes of laryngitis are often misdiagnosed as being the result of acid reflux.<ref>{{Cite journal|last=Brook|first=Christopher|last2=Platt|first2=Michael|last3=Reese|first3=Stephen|last4=Noordzij|first4=Pieter|date=January 2016|title=Utility of Allergy Testing in Patients with Chronic Laryngopharyngeal Symptoms: Is It Allergic Laryngitis?|journal=Otolaryngoly - Head Neck Surgery|publisher=|volume= 154| issue = 1 41–45|doi=10.1177/0194599815607850|pages=41–45}}</ref>


==== Reflux ====
==== Reflux ====
* One possible explanation of chronic laryngitis is that inflammation is caused by gastro-oesophageal reflux which causes subsequent irritation of the vocal folds.<ref>{{Cite journal|last=Joniau|first=Sander|last2=Bradshaw|first2=Anthony|last3=Esterman|first3=Adrian|last4=Carney|first4=A. Simon|date=May 2007|title=Reflux and laryngitis: A systematic review|url=http://dx.doi.org.proxy3.library.mcgill.ca/10.1016/j.otohns.2006.12.004|journal=Otolaryngology - Head and Neck Surgery|volume= 136| issue = 5}}</ref>
* One possible explanation of chronic laryngitis is that inflammation is caused by gastro-oesophageal reflux which causes subsequent irritation of the vocal folds.<ref>{{Cite journal|last=Joniau|first=Sander|last2=Bradshaw|first2=Anthony|last3=Esterman|first3=Adrian|last4=Carney|first4=A. Simon|date=May 2007|title=Reflux and laryngitis: A systematic review|doi=10.1016/j.otohns.2006.12.004|pmid=17478199|journal=Otolaryngology - Head and Neck Surgery|volume= 136| issue = 5|pages=686}}</ref>


==== Autoimmune disorders ====
==== Autoimmune disorders ====
* Approximately between 30-75% of persons with rheumatoid arthritis report symptoms of laryngitis.<ref name="BMJ2014" />
* Approximately between 30-75% of persons with rheumatoid arthritis report symptoms of laryngitis.<ref name="BMJ2014" />
* Symptoms of laryngitis are present in only 0.5-5% of people that have sarcoidosis.<ref name="BMJ2014" /> According to a meta-analysis by Silva et al. (2007), this disease is often an uncommon cause of laryngeal symptoms and is frequently misdiagnosed as another voice disorder.<ref>{{Cite journal|last=Silva|first=Leonardo|last2=Damrose|first2=Edward|last3=Bairao|first3=Fernanda|last4=Nina|first4=Mayra|last5=Junior|first5=James|last6=Costa|first6=Henrique|date=June 2008|title=Infectious granulomatous laryngitis: a retrospective study of 24 cases|url=http://link.springer.com.proxy3.library.mcgill.ca/article/10.1007%2Fs00405-007-0533-4|journal=European Archives of Oto-Rhino-Laryngology|publisher=|volume= 265| issue = 6|doi=10.1007/s00405-007-0533-4|pages=675–680}}</ref>
* Symptoms of laryngitis are present in only 0.5-5% of people that have sarcoidosis.<ref name="BMJ2014" /> According to a meta-analysis by Silva et al. (2007), this disease is often an uncommon cause of laryngeal symptoms and is frequently misdiagnosed as another voice disorder.<ref>{{Cite journal|last=Silva|first=Leonardo|last2=Damrose|first2=Edward|last3=Bairao|first3=Fernanda|last4=Nina|first4=Mayra|last5=Junior|first5=James|last6=Costa|first6=Henrique|date=June 2008|title=Infectious granulomatous laryngitis: a retrospective study of 24 cases|journal=European Archives of Oto-Rhino-Laryngology|publisher=|volume= 265| issue = 6|doi=10.1007/s00405-007-0533-4|pages=675–680}}</ref>


==Diagnosis==
==Diagnosis==
Line 91: Line 91:


=== Visual diagnosis ===
=== Visual diagnosis ===
The larynx itself will often show [[erythema]] (reddening) and&nbsp;[[edema]]&nbsp;(swelling). This can be seen with [[Laryngoscopy|laryngoscop]]<nowiki/>y or [[Stroboscope|stroboscopy]] (method depends on the type of laryngitis).<ref name=":07"/>{{rp|108}} Other features of the laryngeal tissues may include:
The larynx itself will often show [[erythema]] (reddening) and&nbsp;[[edema]]&nbsp;(swelling). This can be seen with [[Laryngoscopy|laryngoscop]]y or [[Stroboscope|stroboscopy]] (method depends on the type of laryngitis).<ref name=":07"/>{{rp|108}} Other features of the laryngeal tissues may include:
* Redness of the laryngeal tissues (acute)
* Redness of the laryngeal tissues (acute)
* Dilated blood vessels (acute)
* Dilated blood vessels (acute)

Revision as of 04:42, 20 December 2016

Laryngitis
Pronunciation
  • /ˌlærənˈtɪs/
SpecialtyPulmonology, otorhinolaryngology Edit this on Wikidata
Symptomshoarse voice, fever, pain[1][2]
Durationusually less than 2 weeks[1]
Causesviral, trauma, bacterial[1]
Differential diagnosisepiglottitis, laryngeal cancer[1]
Treatmentvoice rest, fluids[1]
Frequencycommon[1]

Laryngitis is inflammation of the larynx (voice box).[1] Symptoms often include a hoarse voice and may include fever, cough, pain in the front of the neck, and trouble swallowing.[1][2] Typically, these last under two weeks.[1]

Laryngitis is categorised as acute if it lasts less than three weeks and chronic if symptoms lasts more than three weeks. Acute cases usually occurs as part of a viral upper respiratory tract infection. Other infections and trauma such as from coughing are other causes.[1] Chronic cases may occur due to smoking, tuberculosis, allergies, acid reflux, rheumatoid arthritis, or sarcoidosis.[1][3] The underlying mechanism involves irritation of the vocal cords.[2]

Concerning signs that may require further investigation include stridor, history of radiation therapy to the neck, trouble swallowing, duration of more than three weeks, and a history of smoking. If concerning signs are present the vocal cords should be examined via laryngoscopy. Other conditions that can produce similar symptoms include epiglottitis, croup, breathing in a foreign body, and laryngeal cancer.[1][4]

The acute form generally gets better on its own. Resting the voice and sufficient fluids may help.[1] Antibiotics generally do not appear to be useful in the acute form.[5] The acute form is common while the chronic form is not.[1] The chronic form occurs most often in middle age and is more common in men than women.[6]

Signs and symptoms

The primary symptom of laryngitis is a hoarse voice.[7]: 108  Because laryngitis can have various causes, other signs and symptoms may vary.[8] They can include:

  • Dry or sore throat
  • Coughing (both a causal factor and a symptom of laryngitis)
  • Frequent throat clearing
  • Increased saliva production
  • Dysphagia (difficulty swallowing)
  • Sensation of swelling in the area of the larynx (discomfort in the front of the neck)
  • Globus pharyngeus (feeling like there is a lump in the throat)
  • Cold or flu-like symptoms (which, like a cough, may also be a causal factor for laryngitis)
  • Swollen lymph nodes in the throat, chest, or face
  • Fever
  • General muscle pain (myalgia)
  • Shortness of breath, predominantly in children

Voice quality

Aside from a hoarse-sounding voice, changes to pitch and volume may occur with laryngitis. Speakers may experience a lower or higher pitch than normal, depending on whether their vocal folds are swollen or stiff.[1][9] They may also have breathier voices, as more air flows through the space between the vocal folds (the glottis), quieter volume[10] and a reduced range.[1][1]

Causes

Laryngitis

Laryngitis can be infectious as well as noninfectious in origin. The resulting inflammation of the vocal folds results in a distortion of the sound produced there.[1] It normally develops in response to either an infection, trauma to the vocal folds, or allergies.[3] Chronic laryngitis may also be caused by more severe problems, such as nerve damage, sores, polyps, or hard and thick lumps (nodules) on the vocal cords.[4]

Acute

Viral

Bacterial

Fungal

  • Laryngitis caused by fungal infection is common but not frequently diagnosed according to a review by BMJ and can account for up to 10% of acute laryngitis cases.[1] Patients with both functioning and impaired immune systems can develop fungal laryngitis, which may develop as a result of recent antibiotic or inhaled corticosteroids use.[1] Certain strains of fungi that may cause laryngitis include; Histoplasma, Blastomyces, Candida (especially in immunocompromised persons), and Cryptococcus and Coccidioides.

Trauma

  • Often due to excessive use of the vocal folds such as excessive yelling, screaming, singing. Though this often results in damage to the outer layers of the vocal folds, the subsequent healing may lead to changes in the physiology of the folds.[1] Another potential cause of inflammation may be overuse of the vocal cords.[5][6][7][8][9] Laryngeal trauma, including iatrogenic (caused by endotracheal intubation), can also result in inflammation of the vocal cords.[11]

Chronic

Allergies

  • Findings are unclear as to whether asthma may cause symptoms commonly associated with laryngitis.[1] Some researchers have posited that allergic causes of laryngitis are often misdiagnosed as being the result of acid reflux.[12]

Reflux

  • One possible explanation of chronic laryngitis is that inflammation is caused by gastro-oesophageal reflux which causes subsequent irritation of the vocal folds.[13]

Autoimmune disorders

  • Approximately between 30-75% of persons with rheumatoid arthritis report symptoms of laryngitis.[1]
  • Symptoms of laryngitis are present in only 0.5-5% of people that have sarcoidosis.[1] According to a meta-analysis by Silva et al. (2007), this disease is often an uncommon cause of laryngeal symptoms and is frequently misdiagnosed as another voice disorder.[14]

Diagnosis

  • Acute laryngitis
  • Chronic laryngitis
    • Granulomatous laryngitis
    • Pseudomyxomatous laryngitis

Visual diagnosis

The larynx itself will often show erythema (reddening) and edema (swelling). This can be seen with laryngoscopy or stroboscopy (method depends on the type of laryngitis).[7]: 108  Other features of the laryngeal tissues may include:

  • Redness of the laryngeal tissues (acute)
  • Dilated blood vessels (acute)
  • Thick, yet dry laryngal tissue (chronic)
  • Stiff vocal folds
  • Sticky secretions between the vocal folds and nearby structures (the interarytenoid region)

Referral

Some signs and symptoms indicate the need for early referral.[1] These include:

  • Difficulty swallowing
  • Vocal stridor
  • Ear pain
  • Recent weight loss
  • History of smoking
  • Current or recent radiotherapy treatment (in the neck region)
  • Recent neck surgery or surgery involving endotracheal tubing
  • Person is a professional voice user (teacher, singer, actor and so on)

Treatment

Treatment is often supportive in nature, and depends on the severity and type of laryngitis (acute or chronic).[1] General measures to relieve symptoms of laryngitis include behaviour modification, hydration and humidification.[1]

Vocal hygiene (care of the voice) is very important to relieve symptoms of laryngitis. Vocal hygiene involves measures such as:[1]

  • Resting the voice
  • Drinking sufficient amounts of water
  • Reducing caffeine and alcohol intake
  • Stopping smoking
  • Limiting throat clearing

Voice hygiene programs are given by speech-language pathologists. These programs typically include the following components:[1]

  • Addressing amount and type of voice use
  • Reducing behaviours that are damaging to the vocal folds
  • Increasing hydration
  • Adjusting lifestyle (for example, limiting caffeine and managing medical conditions)

Acute laryngitis

In general, acute laryngitis treatment is involves vocal hygiene, painkillers (analgesics), humidification and antibiotics.[1][5]

Viral

The suggested treatment for viral laryngitis involves vocal rest, pain medication, and mucolytics for frequent coughing.[7] Home remedies such as tea and honey may also be helpful.[1] Antibiotics are not used for treatment of viral laryngitis.[1][15]

Bacterial

Antibiotics may be prescribed for bacterial laryngitis, especially when symptoms of upper respiratory infection are present.[7] However, the use of antibiotics is highly debated for acute laryngitis. This relates to issues of effectiveness, side effects, cost, and possibility of antibiotic resistance patterns. Overall, antibiotics do not appear to be very effective in the treatment of acute laryngitis.[5]

In severe cases of bacterial laryngitis, such as supraglottis or epiglottis, there is a higher risk of the airway becoming blocked.[7] An urgent referral should be made to manage the airway.[1] Treatment may involve humidification, corticosteroids, intravenous antibiotics, and nebulised adrenaline.[7]

Fungal

Fungal laryngitis can be treated with oral antifungal tablets and antifungal solutions.[1][7] These are typically used for up to three weeks and treatment may need to be repeated if the fungal infection returns.[7]

Trauma

Laryngitis caused by excessive use or misuse of the voice can be managed though vocal hygiene measures.

Chronic laryngitis

Reflux

Laryngopharyngeal reflux treatment primarily involves behavioural management and medication.[1][7] Behavioural management involves aspects such as:

  • Wearing loose clothing
  • Eating smaller, more frequent meals
  • Avoiding certain foods (e.g. caffeine, alcohol, spicy foods)[7]

Anti-reflux medications may be prescribed for patients with signs of chronic laryngitis and hoarse voice.[16] If anti-reflux treatment does not result in a decrease of symptoms, other possible causes should be examined.[1] Over-the-counter medications for neutralizing acids (antacids) and acid suppressants (H-2 blockers) may be used.[7] Antacids are often short-acting and may not be sufficient for treatment.[7] Proton pump inhibitors are an effective type of medication.[7] These should only be prescribed for a set period of time, after which the symptoms should be reviewed.[1] Proton pump inhibitors do not work for everyone. A physical reflux barrier (e.g. Gaviscon Liquid) may be more appropriate for some.[1] Antisecretory medications can have several side-effects.[1]

When appropriate, anti-reflux surgery may benefit some individuals.[1]

Inflammatory

When treating allergic laryngitis, topical nasal steroids and immunotherapy have been found to be effective for allergic rhinitis.[7] Antihistamines may also be helpful, but can create a dryness in the larynx.[7] Inhaled steroids that are used for a long period can lead to problems with the larynx and voice.[7]

Autoimmune

Mucous membrane pemphigoid may be managed with medication (cyclophosphamide and prednisolone).[1]

Granulomatous

Sarcoidosis is typically treated with systemic corticosteroids. Less frequently used treatments include intralesional injections or laser resection.[1]

Prognosis

Acute

Acute laryngitis may persist, but will typically resolve on its own within two weeks.[1] Recovery is likely to be quick if the patient follows the treatment plan.[17] In viral laryngitis, symptoms can persist for an extended amount of time, even when upper respiratory tract inflammation has been resolved.[15]

Chronic

Laryngitis that continues for more than three weeks is considered chronic.[1] If laryngeal symptoms last for more than three weeks, a referral should be made for further examination, including direct laryngoscopy.[1] The prognosis for chronic laryngitis varies depending on the cause of the laryngitis.[17]

References

  1. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av Wood, John M.; Athanasiadis, Theodore; Allen, Jacqui (9 October 2014). "Laryngitis". BMJ. 349. The BMJ: g5827. doi:10.1136/bmj.g5827. ISSN 1756-1833. PMID 25300640. Retrieved 21 November 2016.
  2. ^ a b c "Laryngitis - National Library of Medicine". PubMed Health. Retrieved 9 November 2016.
  3. ^ a b Dworkin, James Paul (April 2008). "Laryngitis: Types, Causes, and Treatments". Otolaryngologic Clinics of North America. 41 (2): 419–436. doi:10.1016/j.otc.2007.11.011. PMID 18328379.
  4. ^ Ferri, Fred F. (2016). Ferri's Clinical Advisor 2017: 5 Books in 1. Elsevier Health Sciences. p. 709. ISBN 9780323448383.
  5. ^ a b c Reveiz, L; Cardona, AF (23 May 2015). "Antibiotics for acute laryngitis in adults". The Cochrane database of systematic reviews. 5 (5): CD004783. doi:10.1002/14651858.CD004783.pub5. PMID 26002823.
  6. ^ Dhingra, P. L.; Dhingra, Shruti (2014). Diseases of Ear, Nose and Throat (6 ed.). Elsevier Health Sciences. p. 292. ISBN 9788131236932.
  7. ^ a b c d e f g h i j k l m n o p Colton, Raymond H.; Casper, Janina K.; Leonard, Rebecca (2011). Understanding Voice Problems (4th ed.). Baltimore, MD: Lippincott Williams & Wilkins. pp. 308–309. ISBN 978-1-60913-874-5.
  8. ^ Verdolini, Katherine; Rosen, Clark A.; Branksi, Ryan C., eds. (2006). Classification Manual of Voice Disorders-I. American Speech-Language-Hearing Association. Mahwah, N.J: Lawrence Erlbaum.
  9. ^ Takahashi, H.; Koike, Y. (1976). "Some perceptual dimensions and acoustical correlates of pathologic voices". Acta Oto-laryngologica Supplementum (338): 1–24.
  10. ^ Shipp, Thomas; Huntington, Dorothy A. (1965-11-01). "Some Acoustic and Perceptual Factors in Acute-Laryngitic Hoarseness". Journal of Speech and Hearing Disorders. 30 (4): 350. doi:10.1044/jshd.3004.350. ISSN 0022-4677. PMID 5835492.
  11. ^ Rieger, A.; Hass, I.; Gross, M.; Gramm, HJ; Eyrich, K. (1996). "Intubation trauma of the larynx--a literature review with special reference to arytenoid cartilage dislocation". Anasthesiol Intensivmed Notfallmed Schmerzther. 31 (5): 281–7. doi:10.1055/s-2007-995921. PMID 8767240.
  12. ^ Brook, Christopher; Platt, Michael; Reese, Stephen; Noordzij, Pieter (January 2016). "Utility of Allergy Testing in Patients with Chronic Laryngopharyngeal Symptoms: Is It Allergic Laryngitis?". Otolaryngoly - Head Neck Surgery. 154 (1 41–45): 41–45. doi:10.1177/0194599815607850.
  13. ^ Joniau, Sander; Bradshaw, Anthony; Esterman, Adrian; Carney, A. Simon (May 2007). "Reflux and laryngitis: A systematic review". Otolaryngology - Head and Neck Surgery. 136 (5): 686. doi:10.1016/j.otohns.2006.12.004. PMID 17478199.
  14. ^ Silva, Leonardo; Damrose, Edward; Bairao, Fernanda; Nina, Mayra; Junior, James; Costa, Henrique (June 2008). "Infectious granulomatous laryngitis: a retrospective study of 24 cases". European Archives of Oto-Rhino-Laryngology. 265 (6): 675–680. doi:10.1007/s00405-007-0533-4.
  15. ^ a b Dominguez, L. M.; Simpson, C. B. (December 2015). "Viral laryngitis". Current Opinion in Otolaryngology & Head and Neck Surgery. 23 (6): 454–458. doi:10.1097/moo.0000000000000203.
  16. ^ Schwartz, Seth R.; Cohen, Seth M.; Dailey, Seth H.; Rosenfeld, Richard M.; Deutsch, Ellen S.; Gillespie, M. Boyd; Granieri, Evelyn; Hapner, Edie R.; Kimball, C. Eve (2009-09-01). "Clinical Practice Guideline Hoarseness (Dysphonia)". Otolaryngology -- Head and Neck Surgery. 141 (3 suppl): S1–S31. doi:10.1016/j.otohns.2009.06.744. ISSN 0194-5998.
  17. ^ a b Jonas, Nico (2007). "Laryngitis Management". Journal of Modern Pharmacy. 14 (5): 44.