Signs, symptoms, clinical examination findings and etiology of the various types of otitis
Part 1

     Otitis means inflammation of the ear. To discuss the different types of  otitis or inflammations of the ear, I start with a basic anatomy of the ear.  The ear is divided into three parts; external, middle and internal ear. The external ear is divided into the auricle and the external auditory meatus which is continuous with the tympanic membrane. The tympanic membrane is divided into the pars flaccida, the superior aspect, and pars tensa, the remaining portion of the membrane. The middle ear or tympanic cavity is essentially the tympanic membrane and three openings. There is a round and an oval opening, which provide for the communication with the inner ear and the last opening is the Eustachian tube (ET), which provides for a mechanism to drain into the Para nasal sinuses. The internal ear or labyrinth is the main part of the hearing organ with the main distribution of the auditory nerves [6,7]. 
Otitis Externa
Inflammation of the external ear is called Otitis Externa and depending on its presentation  can be either acute, furuncular or malignant. Acute Otitis Externa could occur in one or both ears and is usually associated with discharge of an exudate. In the case of a creamy exudate, the cause could be Pseudomonas infection. A cheesy discharge is usually associated with fungal Otitis Externa, and in the case of no exudate the case is usually dermatitis. In acute Otitis Externa the ear canal is red or scaly in the mild cases and edematous and filled with exudate in severe cases. Pressure on the tragus or any movement of the auricle intensifies the pain. Itching is often present without fever in most cases. Otitis Externa is usually associated with water sports and occurs mostly in hot and humid areas. It could also be caused by trauma to the canal with external objects like cotton swab [2,5].
Furuncular Otitis Externa is usually presented with severe pain and local tenderness in the outer portion of one ear canal, with the pain intensifying through movement of the auricle or tragus. Swelling may be present around the ear as well. Upon inspection of the ear canal a white-capped, red-based furuncle could be identified near the external meatus. Drainage of this abscess will provide immediate pain relief [5,6].
Malignant Otitis Externa is more common among elderly males and the usual duration of symptoms before diagnosis is 3 to 8 weeks. This could be a dangerous infection of the external ear and skull base and prompt treatment is required. A common characteristics among all patients is DM. This disorder usually presents with severe to excruciating pain in one ear which may be accompanied by severe headache in the temporal or occipital area. The most common causative agent is Pseudomonas aeruginosa and therefore, long-term oral antipseudomonal agents have been shown to be effective [5,6].
Otitis Media (OM)
This is an inflammation of the middle ear that could result from the occlusion of the ET or an infection. This condition is very common among young children and it’s usually as a result of a complication of other conditions such as coryza and sinusitis. According to American Chiropractic Association (ACA), 60% of children will experience OM in the first year of life and about 17% will have recurrence the same year. The same source indicates that the incidence of OM has had an increase of 250% from 1975 to 1990. The direct annual costs for the treatment of OM has been estimated at US$5.3 billion, which is increased to US$8 billion once indirect expenses are taken into account as well. Among  the risk factors for developing OM are young age, large daycares, exposure to cigarette smokes, formula fed, premature birth, and family history of OM. Complications of OM are rare and about 1 in 10,000 may experience infectious complications such as mastoiditis, petrositis, labyrinthitis, conductive and sensorineural hearing lost, or meningitis leading to serious illness or death. Among signs of impending complications are headache, vertigo, and sudden profound hearing loss  [2,3,11]. Different classifications of OM based on their clinical presentation, duration and type of the exudate are as follows:
Acute Otitis Media (AOM) is generally seen in young children up to 7 years of age usually following an upper respiratory infection. According to the 2009 position statement by the Canadian Paediatric Society (CPS), young age and daycare attendance are the major risk factors for AOM. Other risk factors as partly mentioned above include orofacial abnormalities, household crowding, exposure to cigarette smoke, premature birth, not being breastfed, immunodeficiency, and a positive history of OM. At higher risk are also children of First Nation or Inuit ethnicity. AOM has a duration of less than 3 weeks with clinical presentations such as fever, headache, irritability, earache that is aggravated by swallowing, auricular discharge, throbbing earache, which subsides in 6-9 hours. Infants may also present with vomiting and diarrhea. Viruses play an important role in the pathogenesis of AOM and if the patient presents with a pink eardrum or watery rhinitis then viral infection should be suspected. A bacterial infection is suspected in patients who present with fever, acute tender ear, irritability, and a bulging red eardrum. In fact, studies using tympanocentesis have shown bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis to be present in most cases [2,3,7,9,11].
Serous Otitis Media, or glue ear, or Otitis Media with Effusion (OME), or chronic Otitis Media usually follows an episode of AOM, nasopharyngeal inflammation, allergy, or hypertrophy of adenoids. In this disorder due to the fullness of the middle ear with sterile exudate the tympanic membrane is immobile and dull, but there is no superimposed infection and it may or may not be painful. This is more common in children due to a more horizontal/narrower ET. It usually lasts longer than 3 months and among its clinical presentations are: stuffiness of the involved ear, conduction deafness, dull or blue tympanic membrane, which is immobile. It is usually asymptomatic and is also associated with learning disabilities.  It can resolve within days or weeks or it can persist for months. Referral is recommended should there be sings of hearing impairment, delayed speech development, repeated recurrence of infection in the middle ear, or retraction of the tympanic membrane evident. This could result in conductive hearing loss. The treatment is usually by managing the underlying cause of  ET blockage [2,6,7].
Otitis Interna
Otitis Interna or Labyrinthitis is an inflammation of the labyrinth which is located within the inner ear and is most commonly caused by bacterial infection. This infection usually follows another infection as for example in Acute Otitis Media or meningitis. Clinical presentations of Otitis Interna could include nausea and vomiting, feeling of  unsteadiness, hearing impairment or possible deafness, ringing in the ear, vertigo. Otitis Interna caused by infection could be prevented in most cases by prompt treatment of Acute Otitis Media or meningitis, however, for the viral causes there is no known way for prevention. Medical treatment of bacterial labyrinthitis is usually through antibiotics and in the viral cases corticosteroids such as prednisone is used [6].
Continue to Part 2
1) Brown C.D. Improved hearing and resolution of Otitis Media with Effusion following chiropractic care to reduce vertebral                  subluxation. Journal of Pediatrics, Maternal & Family Health Chiropractic. 2009 March; 1-4.
2) Jamison J.R. Differential diagnosis for primary care, A hand book for health care practitioners. 2nd ed. 2006.
3) Sanders L. Chiropractic treatment of Otits Media with Effusion: a case report and literature review of the epidemiological risk            factors that predispose towards the condition and that influence the outcome of chiropractic treatment. Clinical Chiropractic,            2004 March, Vol.7;168-173.
4) Fallon J.M. The Role of the chiropractic adjustment in the care and treatment of 332 children with Otits Media. JCCP, 1997 Jan.          Vol.2;167-170.
5) Wiener S.L. Differential diagnosis of acute pain by body region. 1993.
6) Lamm L, Ginter L. Otitis Media: A conservative chiropractic management protocol. Clinical Chiropractic, 1998 March, Vol.5;18-27.
7) Hendricks CL, Markin SM. Otitis Media in young children. Chiropractic, 1989 January, Vol.2;9-12.
8) Clinical Practice Guidelines for diagnosis and management of Acute Otitis Media; American Academy of Pediatrics (AAP) and              American Academy of Family Physicians (AAFP); 2004.  aappolicy.aappublications.org
9) Forgie S, Zhanel G, Robinson J, Management of acute otitis media – a summary. Canadian Paediatric Society, Infectious Diseases      and Immunization Committee; Position Statement 2009. Paediatric Child Health; Sep. 2009, 14(17):457-459.
10) Wickens K, Pearce N, Crane J, Beasley R, Antibiotic use in  early childhood and the development of asthma. Clinical and                      Experimental Allergy 1999;29(6):766-771.
11) Hewitt EG, Chiropractic Care for Otitis Media: Clinical Rationale, State of Research and Treatment Protocols. American                        Chiropractic Association Live Teleseminar Series; Jan. 2008.
12) Del M, Glaziou P, Hayern M, Are antibiotics indicated as initial treatment for children with  acute otitis media? A meta-analysis.          British Medical Journal 1997;314(7093)1526-1529.
13) Paradise JL, Feldman HM, Campbell TF, et al. Effect of early or delayed insertion of tympanostomy tubes for persistent otitis              media on development outcomes at ages of three years. New England Journal of Medicine: 2001;344(16):1179-1187.
14) Spiro DM, Tay R, Arnold DH, et al. Wait-and-see prescription for the treatment of acute otitis media: a randomized controlled            trial. Journal of the American Medical Association 2006;269(10):1235-1241.
15) Chila AG, Foundations of Osteopathic Medicine. 3rd ed. Baltimore: Lippincott Williams & Wilkins; 2011.
16) Carreiro JE, An Osteopathic approach to children. 2nd ed. Toronto: Churchill Livingstone; 2009.
17) Pollentier A, Langworthy JM, The Scope of Chiropractic Practice: A Survey of Chiropractors in the UK. Clinical Chiropractic, Sep.          2007;10(3):147-155.