Nose and Oropharynx

Question 1

The nasopharynx has three functions:

Answer 1

 Facilitation of respiration
 Olfaction
 Modification of speech sounds

Question 2

Facilitation of respiration

Answer 2

Air enters the nasopharynx through the external nares (the nostrils). The air is turbinated (made turbulent) by the conchae (plates of bone within the nasopharynx) and filtered by the nasal hairs. These can trap particles of > 6 m in mucous. The air is also warmed and moistened as it passes over the mucous membrane.

Question 3

The olfactory apparatus (sense of smell = olfaction)

Answer 3

Impulses from the olfactory receptors are transmitted through the olfactory nerves. These mostly enter the olfactory bulb in the cerebral cortex although some are sent to the limbic system and the hypothalamus. These latter routes of transmission are responsible for the emotional and memory associations of smell. The impulses end within the orbitofrontal area of the brain. The olfactory apparatus is shown in Figure 1.

Question 4

The olfactory apparatus

Answer 4

Mucous moistens the surface of the olfactory plate and dissolves odourants. Olfaction has a very low threshold – for example the olfactory plate can detect methyl mercaptan (a thiol ‐ CH3SH) at an olfactory threshold of as low as 0.04 picograms per litre of air. Methyl mercaptan smells of rotting cabbage and it is added in very tiny quantities to natural gas (which is odourless) to enable leaks to be detected by smell.
The supporting cells are columnar epithelial cells of mucous membrane which provide physical support, nourishment and electrical insulation for the olfactory receptor cells. The supporting cells also have a role in detoxifiying chemicals that come into contact with the olfactory apparatus.
The olfactory receptor cells are bipolar neurons with the dendrite (ending in the olfactory hairs) in the olfactory plate and the axon in the olfactory bulb. The average lifespan of an olfactory receptor cell is approximately one month. The basal cells are stem cells located in the supporting cells. These divide continuously to produce new olfactory receptor cells.
The Bowman’s glands which are located within the connective tissue are innervated by the facial (VII) nerve, stimulation of which causes the production of mucous. When stimulated by certain chemicals (e.g. onions, peppers), the Bowman’s glands will produce excess mucous resulting in a runny nose. There is very little to be done about this although there are many old wives tales about how to prevent it – e.g. when cutting onions hold a wooden spoon between your teeth or place a piece of bread between your upper lip and your nose. The idea of these is to absorb the odorant but they are generally ineffective.

Question 5

Sinuses

Answer 5

 Frontal
 Sphenoidal
 Maxillary
 Ethmoid (This is a collection of air cells rather than one sinus cavity)

The sinuses are lined with ciliated columnar epithelium beneath which lie seromucinous glands
producing mucous, IgA and other immunoglobulins.

Question 6

Pathology of the sinuses – acute sinusitis

Answer 6

Acute maxillary sinusitis is the most common. The mucosa of the sinuses swells leading to blockage of the drainage foramen. This inflammation may be due to the common cold, influenza or allergic rhinitis. The stasis of the mucous can lead to possible secondary bacterial infections within the sinuses. The symptoms of acute maxillary sinusitis are related to the relationship of the maxillary sinuses with other structures within the skull – the top of the sinus forms the base of the orbit (the eye socket) whilst the floor of the sinus is connected to the roots of the second premolar tooth and the first two molar teeth. Classically a patient will present with discomfort or pain around the base of the eye and also discomfort within the teeth particularly when chewing.
The next most common form is that of acute sinusitis due to obstruction of the drainage of the frontal and ethmoid sinuses. The mucous secretions accumulate and form a mucocele. This very rarely progresses to a secondary bacterial infection. The classic symptoms include pain above the eyes (frontal sinuses are affected) and/or around the nose (ethmoid sinuses are affected). The skin of the skull over the affected sinuses may be tender when put under light pressure. If the frontal sinuses are affected, the patient may experience pain when they lean forward.

Question 7

Acute sinusitis ‐ treatment

Answer 7

The headache associated with acute sinusitis may be treated with simple analgesia such as paracetamol, aspirin or ibuprofen as appropriate to the patient. The nasal congestion causing the sinusitis may respond to the systemic decongestant pseudoephedrine or topical decongestants (ephedrine, oxymetazoline and xylometazoline).
Topical sympathomimetic nasal decongestants can be very effective at relieving nasal congestion but they have a problematic side effect of rebound congestion upon withdrawal. If they are used for a greater duration than seven days, tolerance may develop and the effect may diminish. Topical sympathomimetics should be used with caution in patients with diabetes, hypertension, hyperthyroidism, ischaemic heart disease, closed angle glaucoma and prostatic hypertrophy.
Pseudoephedrine is not as effective as topical decongestants but it does not have any rebound nasal congestion on withdrawal of therapy. Because it is a weak sympathomimetic agent it has the same cautions as the topical nasal decongestants listed above.
If a bacterial infection is suspected, the patient should be referred as antibiotics may be required.

Question 8

Pathology of the sinuses – chronic sinusitis

Answer 8

This may follow untreated or repeated bouts of acute sinusitis. It may also be caused by:
 Nasal polyps. These are overgrowths which are lined with respiratory epithelium and contain seromucous glands, goblet cells and inflammatory cells.
 Chronic inhalation of irritants – e.g. cigarette smoke – where the initial toxic allergic reaction to the inhalant becomes chronic resulting in a thickened mucous membrane.
Chronic sinusitis often requires referral to a specialist in the nasopharynx for long term treatment.

Question 9

Epistaxis (nose bleeds)

Answer 9

Nose bleeds are very common as the nasal epithelium is highly vascularised. Most often the cause is trauma from vigorous nose picking, a blow to the nose or acute rhinitis (which results in vigorous sneezing and/or nose blowing). The usual site is the anterior septum (Little’s area). Generally a nose bleed is not serious and can be managed by leaning the patient forward, pinching the fleshy portion of the nose and allowing the blood to clot. Patients should be told to avoid blowing their nose for a few hours afterwards to avoid disturbing the clot. Patients with bleeding disorders such as haemophilia, or who are taking anticoagulants may be at risk of a longer bleed which may require nasal packing or cautery (heat sealing) of the bleeding vessel(s). Such patients should be referred to A&E if the nose bleed does not settle within 10 minutes or so of beginning.

Question 10

Nasal tumours

Answer 10

Tumours of the nose and paranasal sinuses are very uncommon. Of those that do occur, the most common are sinonasal papillomas which are benign. These are most common in men aged over 60 and are treated by total excision. Inverted papillomas are the most significant as if these are left untreated they may develop into frank carcinoma.

Question 11

The Common Cold

This is a viral infection caused by:

Answer 11

 Rhinoviruses (100+ types)
 Adenoviruses
 Coronaviruses
 Respiratory syncytal virus (RSV)
 Parainfluenza viruses

Question 12

The clinical signs of a common cold include

Answer 12

The clinical signs of a common cold include rhinorrhoea (a runny nose), nasal obstruction, sneezing, pyrexia, myalgia.

Question 13

The pathogenesis of a common cold is as follows:

Answer 13

1. The nasal mucosa becomes thickened, oedematous and reddened.
2. The nasal cavities are therefore narrowed and the conchae become enlarged.
3. During the first two to three days of a cold the mucous contains dead epithelial cells
   containing viral inclusions. Necrosis of these epithelial cells leads to exudation of fluid and mucous which are the most common symptoms of the common cold.

Question 14

Common cold – treatment

Answer 14

The common cold is a self‐limiting infection which can be treated symptomatically. Simple analgesics (paracetamol, aspirin, ibuprofen) can be recommended as appropriate to treat headache, pyrexia and myalgia associated with the common cold. Nasal congestion can be treated with topical or systemic decongestants as described earlier in the treatment of acute sinusitis. Sneezing is associated with the shedding of dead epithelial cells and will lessen as the cold progresses and the patient improves in health.

Question 15

Allergic rhinitis (including hayfever)

Answer 15

Patients suffering from allergic rhinitis commonly present with symptoms of sneezing; itching nose and/or palate; a runny nose (the exudate is usually clear); nasal congestion; red, watery, itchy eyes (bilateral symptoms); disturbed sleep and hence tiredness and listlessness. Treatment of eye symptoms will be dealt with in a separate eBook.

Question 16

Symptoms of allergic rhinitis

Answer 16

Symptoms of allergic rhinitis lasting for less than four weeks or less than four days per week indicate an intermittent (or seasonal) allergy with pollen being the most typical allergen. This is known as ‘hayfever’. Patients may present with hayfever symptoms at any point in the year when pollen is released into the air. The first pollens are tree pollens which may appear at any point from February onwards with birch pollen appearing to be the most allergenic. 90% of hayfever sufferers are allergic to grass pollens and these tend to appear from April/May until the end of summer. Seeds from weeds which flower later in the summer such as nettles and dock plants, may also cause hayfever. Patients may be asymptomatic on days when there is little wind to carry the pollen or on wet days when the pollen cannot rise.

Symptoms of allergic rhinitis lasting longer than four weeks or for more than four days per week indicate that the patient has a perennial allergy. Most commonly the allergens in cases of perennial allergies are house dust mite faeces and pet dander (usually dogs or cats).

Question 17

Allergic rhinitis – non‐medication management

Answer 17

Allergen avoidance is one of the most effective treatments of allergic rhinitis although this can be difficult to achieve. The following points may be advised:
Hayfever
 Remain indoors if possible when pollen counts are high (pollen counts are generally given with regular weather forecasts)
 Keep doors and windows closed
 Avoid obvious areas where pollen may be present such as parks, fields etc., particularly
after grass has just been cut (this liberates enormous amounts of pollen)
 Wear sunglasses when outside (this helps with eye symptoms) and wash face and hands
once indoors
 If pets go outside, wipe down their fur when they come back into the house to remove
any pollen
Perennial allergic rhinitis
It is recognised that bedrooms and bedding are the places where most house dust mite allergens will build up and cause a problem. There is little evidence to support the usefulness of measures taken to avoid house dust mite allergens. Most domestic vacuum cleaners are not powerful enough to remove the allergens from mattresses and pillows; they may, in fact, simply release more allergens into the air. Some polyethylene bedding may give some protection but it must be robust enough to stand repeated washing and there is little evidence to support its effectiveness.

Question 18

Allergic rhinitis – medication management

Answer 18

Oral antihistamines are effective at relieving the itchiness, sneezing and rhinorrhoea of allergic rhinitis. They are not particularly effective if the patient complains of nasal congestion. An oral antihistamine must be carefully selected; first generation antihistamines such as chlorphenamine are effective but may cause excessive sedation (this may be appropriate if the patient is suffering from poor sleep as a result of their allergy). Second generation antihistamines such as loratidine, cetirizine and acrivastine are less likely to cause sedation.
The antihistamine azelastine is available as a nasal spray to treat allergic rhinitis. In seasonal rhinitis its use should begin at least 2‐3 weeks before the allergen season begins. It is quicker to act than oral antihistamines and has the same spectrum of activity. It is not particularly effective against nasal congestion and can be used with an intranasal decongestant or steroid to relieve congestion.
Intranasal steroids are very effective at relieving the sneezing, rhinorrhoea and congestion associated with allergic rhinitis. They are slightly less effective against nasal itchiness. As with intranasal antihistamines, treatment ideally should begin at least 2‐3 weeks before the allergy season begins. There are several corticosteroids available as intranasal formulations: beclometasone, budesonide, flunisolide, fluticasone, mometasone and triamcinolone. Of these, beclometasone, budesonide, and triamcinolone (all as non‐pressurised nasal sprays) can be recommended over the counter, but only for adults aged 18 or over.

Question 19

The mouth is classified into two compartments:

Answer 19

 The oral vestibule
o Between the lips and the teeth
 The oral cavity
o From the gums and teeth to the fauces. The fauces is the opening between the oral cavity and the oropharynx (the throat)

Question 20

The Cheeks

Answer 20

Within the mouth, the cheeks form the lateral walls of the oral cavity. They are covered externally with skin and internally with mucous membrane. The cheeks contain the buccinators muscles and connective tissue. The lips are covered in the same manner as the cheeks and are attached to the gums via a midline fold of mucous membrane called the labial frenulum. The cheeks and lips have three functions: structural, digestive and communication. They form the boundaries of the oral cavity and the oral vestibule and the muscles within keep food between the teeth and assist in speech by helping to form sounds.

Question 21

The Palate

Answer 21

There are two types of palate within the oral cavity. The hard palate makes up the anterior portion of the roof of the mouth and is formed by the maxillae and palatine bones. The soft palate forms the posterior portion of the roof of the mouth and it is an arch shaped muscular partition. Both the hard and soft palates are covered by mucous membrane. The uvula is a soft conical muscular process that hangs from the soft palate. During swallowing, the soft palate and the uvula are drawn up towards the skull. The palate forms the barrier separating the oral cavity from the nasal cavity and allows us to chew and breathe simultaneously. It also prevents food and liquids from entering the nasal cavity on swallowing.

Question 22

The tonsils

Answer 22

The tonsils are aggregates of lymphatic nodules (mucosa associated lymphatic tissue – MALT) and there are five in total forming a ring at the junction of the oral cavity and oropharynx and the nasal cavity and the nasopharynx.
 The pharyngeal (adenoid) tonsil is located in the posterior wall of the nasopharynx
 The palatine tonsils are found in the posterior region of the oral cavity (one on each
side)
 The lingual tonsils are found at the base of the tongue (one on each side).
The lingual and palatine tonsils are most commonly removed during tonsillectomy.
The tonsils perform an important role in the immune response against inhaled and ingested foreign substances.

Question 23

The tongue

Answer 23

The tongue is made up of extrinsic and intrinsic skeletal muscles covered in mucous membrane. The extrinsic muscles originate outside the tongue (they are attached to the bones within the area) and insert into the connective tissue in the tongue. These muscles move the tongue from side to side and in and out. They are responsible for manoeuvring food within the mouth for chewing and also for shaping food for swallowing. They also hold the tongue in place. The intrinsic muscles originate within the tongue and alter the shape and size of the tongue for speech and swallowing. The lingual frenulum (the ridge underneath your tongue) limits posterior movement of the tongue. If this is short or rigid it leads to the development of a speech impediment (being “tongue‐tied”).
The dorsal and lateral surfaces of the tongue are covered with papillae which are projections of lamina propria covered in epithelium. Some of these papillae contain taste buds and others receptors for touch. These latter papillae sense the increase in friction in response to food and ease swallowing. The tongue is therefore the principal source of information regarding the taste and texture of food.

Question 24

Teeth

Answer 24

The teeth are located in sockets of the mandible and maxillae bones lined with periodontal ligament which is dense fibrous connective tissue that anchors the teeth to the sockets. Each tooth has three regions:
 Crown
o The visible part of the tooth above the gum line
 Neck
o The junction of the crown and the root at the gum line
 Root
o Embedded within the socket (there are between 1 and 3 roots per tooth)

Question 25

Teeth are made up of:

Answer 25

 Dentin. This forms the bulk of the tooth and is calcified connective tissue. The amount of calcium in dentin is higher than in bone and so dentin is harder than bone. The dentin gives the tooth shape and rigidity.  Enamel. This covers the dentin on the crown of the tooth and is made up of calcium carbonate and calcium phosphate. It is the hardest substance in the body and protects the body of the tooth from acids and wear and tear.  Cementum. This covers the dentin on the root of the tooth and attaches the root of the tooth to the periodontal ligament.  Pulp cavity. This is located within the crown and consists of connective tissue containing blood vessels, nerves and lymphatic vessels.  Root canals. These run from the pulp cavity to the root. Humans usually get through two sets of teeth (dentitions) in their life time. The first set (known as the primary, milk or baby teeth) consists of 20 deciduous teeth which begin to erupt at around 6 months of age (although they may appear much earlier) and are lost between the ages of 6 and 12 years. The second, permanent set consists of (usually) 32 teeth made up of incisors, canines, premolars and molars. Incisors are for cutting, canines (cuspids) for tearing and shredding, premolars (bicuspids) for crushing and grinding as are the molars. The third molars (the wisdom teeth) do not always erupt. Teeth also play a part in the formation of speech.

Question 26

Salivary glands

Answer 26

The salivary glands release saliva and mucous into the oral cavity. There are many small glands within the mucous membrane which only have a small contribution to saliva production. There are three pairs of major glands which lie beyond the oral mucosa and the saliva produced by these glands is secreted into ducts. These pairs of major glands are the:  Parotid – located near the ears  Submandibular – in the floor of the mouth  Sublingual – beneath the tongue There are also lingual glands in the lamina propria of the tongue. These secrete lingual lipase which acts on triglycerides in food. Saliva is produced to keep the mucous membranes of the mouth moist, cleanse the mouth and to mix with food. It dissolves food so that digestion can begin and lubricates the food to ease swallowing. Saliva is 99.5% water (to dissolve food), the remaining 0.5% being solutes. These include ions, dissolved gases, IgA, lyzosyme and salivary amylase. This latter solute begins the breakdown of starches within foods as they are being chewed. Saliva production is controlled by parasympathetic stimulation following the presence, sight or smell of food.

Question 27

The oropharynx (the throat)

Answer 27

The pharynx is the name given to the cavity at the back of the nose and mouth. It consists of skeletal muscle covered with mucous membrane and is divided into three sections:  Nasopharynx – from the nostrils to the soft palate  Oropharynx – from the soft palate to the epiglottis  Laryngopharynx – from the epiglottis to the oesophagus. The laryngopharynx opens into the larynx (the voice box) and the oesophagus. The oropharynx has both digestive and respiratory functions.

Question 28

Pharyngitis (throat infection)

Answer 28

Bacterial, viral and fungal pharyngitis can all occur. Bacterial pharyngitis is uncommon and is usually caused by streptococci. Viral pharyngitis is extremely common and often forms part of the symptomology of the common cold or influenza. It is self‐limiting and requires only rest and fluids as treatment. Patients may benefit from gargling aspirin (if the drug is not contra‐ indicated) or warm salt water. Sucking throat lozenges can soothe a sore throat as this encourages the production of saliva which then lubricates the inflamed area. If the throat is very sore, lozenges and throat sprays containing local anaesthetics are available. There is little evidence of their benefit and they should be used with caution; patients should be warned about drinking hot liquids as they may inadvertently burn their throats whilst the local anaesthetic is in effect. The most severe form of viral pharyngitis is infectious mononucleosis (glandular fever) caused by the Epstein Barr virus (EBV) which can be extremely debilitating. Fungal pharyngitis is uncommon in adults and indicates that the patient is immunocompromised or may have undiagnosed diabetes mellitus. Therefore when a patient presents with a sore throat, the pharmacist should question the patient very carefully about the duration of the current condition, the level of discomfort, any history of past episodes and any other symptoms, for example symptoms of a common cold. The appearance of the pharynx may be indicative, but unless there is a severe bacterial infection it is unlikely that the pharmacist will be able to distinguish between viral and bacterial infections. The NICE CKS for sore throats can be found here. The soft palate and the tonsils may be very swollen and red, and pus may be present in severe bacterial infections, particularly streptococcal infections. These symptoms necessitate a referral to appropriately qualified practitioners. Other alarm symptoms that require referral are the presence of large, tender lymph nodes and/or difficulty in swallowing food or drink. The presence of a sore throat for two weeks or longer should also prompt referral as this may be a symptom of infectious mononucleosis (glandular fever).

Question 29

Tonsillitis

Answer 29

Acute tonsillitis is cause by widespread acute bacterial or viral pharyngitis. The tonsils become swollen and red due to mucosal hyperaemia. A creamy acute inflammatory exudate may be present as creamy yellow spots on the surface of the tonsils. Quinsy presents as a painful inflammation of the throat (including the tonsils) with a fever. It may prevent swallowing due to the formation of peri‐tonsillar abscesses which can lead to a risk of suffocation. In adults the tonsils usually reduce in size as the lymphoid tissue atrophies; however they can remain prominent. A tonsillectomy may be required if there is:  recurrent tonsillitis (5 episodes per year for at least two years)  quinsy with a history of recurrent tonsillitis  obstructive sleep apnoea secondary to tonsillar hypertrophy  malignancy

Question 30

Aphthous ulcers

Answer 30

Aphthous ulcers are classified into two types, minor and major. Minor aphthous ulcers are generally small (5‐8 mm in diameter), regular and round in shape, with a typical appearance of a well‐defined, inflamed outer margin and a “floor” which is white or yellowish in colour. Minor aphthous ulcers occur on the sides of the cheeks, the inside of the lips and on the tongue. They can be extremely painful whilst present but generally heal within 7‐14 days without any scarring. Minor aphthous ulcers may occur spontaneously (there is thought to be a genetic link) or following trauma such as biting the inside of the lips, trauma to the mouth or face, or poorly fitting dentures. If the latter is suspected to be the cause, the patient should be referred back to their dentist to ensure the correct fit of their dentures. Minor aphthous ulcers do not generally require treatment. However patients may benefit from the use of chlorhexidine mouthwash, benzydamine mouthwash, topical anti‐inflammatories or topical analgesics. Several other conditions may present with similar symptoms to minor aphthous ulcers and all require referral to appropriately trained practitioners. Major aphthous ulcers are a more severe form of the condition with larger ulcers (up to 30 mm in diameter) occurring in crops of 10 or more (sometimes merging into one huge ulcer). These take longer to heal (up to 30 days) and symptomatic relief (as outlined above) is required.

Question 31

Herpetiform ulcers

Answer 31

Herpetiform ulcers are much smaller in size (pinpoint in size) and occur in crops of up to 100, usually towards the back of the mouth. These take up to 30 days to heal and a fresh crop often appears before the previous batch have fully healed. Despite their smaller size, they can be intensely painful.

Question 32

Oral candidiasis

Answer 32

Oral candidiasis presents as creamy plaques on the inside of the cheeks. Unlike aphthous ulcers, this plaque can be scraped off to reveal the raw tissue underneath. Oral candidiasis is common in small babies and can be treated with oral miconazole gel.

Question 33

Squamous cell carcinoma

Answer 33

Squamous cell carcinoma often appears to be the same as a minor aphthous ulcer. However it is initially painless, becoming more painful over time, and does not heal. If this history is given by the patient they should be referred immediately for a medical opinion.

Question 34

Gingivitis

Answer 34

Gingivitis is inflammation of the gums (the gingiva) and is caused by bacterial plaque. The most common symptom of gingivitis is bleeding of the gums, especially when the teeth are brushed. The gums may be swollen and sore and the patient often complains of halitosis (bad breath). It is treated by introducing and maintaining good oral hygiene and by the use of antibacterial mouthwashes such as chlorhexidine 0.2%.

Question 35

Xerostomia

Answer 35

Xerostomia (dry mouth) can be caused by several mechanisms. The patient may be suffering from Sjörgren’s syndrome, obstruction of salivary glands or they may be taking a drug which causes dry mouth such as: tricyclic antidepressants, benzhexol, some chemotherapeutic agents, antihistamines (H1 blockers), atropine, levodopa. Dry mouth is not only very uncomfortable, but it also predisposes patients to pathological conditions of the oral mucosa including oral candidiasis, aphthous ulcers and dental caries. Artificial saliva sprays are available to relieve the symptoms of xerostomia.

Question 36

Cold sores

Answer 36

Cold sores are caused by infection with the Herpes simplex virus type 1 (HSV‐1). The infection is often contracted in childhood and may be asymptomatic or confused with an episode of teething. Following the initial infection, the virus lies dormant within the nervous system and reinfection recurs following exposure to one of many trigger factors. These include: the common cold, exposure to the sun, fatigue, stress, the menstrual cycle, exposure to cold weather or wind, trauma to the mouth. Cold sores are often preceded 24 hours before by a burning or tingling sensation in the affected area. A painful blister then forms which bursts quite quickly leaving a weeping sore which then crusts over. Cold sores usually take between 7 and 10 days to heal. Cold sores are very difficult to treat and even systemic antiviral agents are not wholly effective. Aciclovir and penciclovir creams are available for purchase over the counter. Aciclovir should be applied five times a day, whilst penciclovir is applied every two hours during waking hours. Both can be started during the prodromal phase and it is claimed that this will speed healing, although there is little evidence to support this.