Anosmia Health Dictionary

Certain skin diseases – particularly CHILBLAIN, ACNE, LUPUS and ERYSIPELAS – tend to affect the NOSE, and may be very annoying. Redness of the skin may be caused by poor circulation in cold weather.

Acute in?ammation is generally the result of a viral infection (see COLD, COMMON) affecting the mucous membrane and paranasal sinuses (see SINUSITIS); less commonly it results from the inhalation of irritant gases. Boils may develop just inside the entrance to the nose, causing pain; these are potentially troublesome as infection can spread to the sinuses. HAY FEVER is one distressing form of acute rhinitis.

Malformations are of various kinds. Racial and familial variations in the external nose occur and may be a reason for RHINOPLASTY. Di?erences in the size and shape of the nose occur, often forming the starting point for chronic in?ammation of the nose, perennial rhinitis (all the year round), hay fever, or ASTHMA. More commonly, obstruction results from nasal polyps or adenoids, leading to inhalation through the mouth. Adenoids are an overgrowth of glandular tissue at the back of the throat, into which the nose opens. Polyps are growths of soft jelly-like character: they arise from chronic in?ammation associated with allergic rhinitis, chronic sinusitis, asthma, and aspirin abuse. Large polyps can cause erosion of the nasal bones and should be surgically removed.

Bleeding (see HAEMORRHAGE).

Foreign bodies At ?rst these may not cause any symptoms, but in time they can cause obstruction of the affected nostril with a foul-smelling bloody discharge. The problem is common with small children who tend to push small objects into their noses. Foreign bodies require removal, sometimes in hospital. Anyone attempting to remove a foreign body should take care not to push it further into the nose.

Loss of sense of smell, or anosmia, may be temporary or permanent. Temporary anosmia is caused by conditions of the nose which are reversible, whereas permanent

anosmia is caused by conditions which destroy the OLFACTORY NERVES. Temporary conditions are those such as the common cold, or other in?ammatory conditions of the nasal mucosa or the presence of nasal polyps (see above). Permanent anosmia may follow in?uenzal NEURITIS or it may also follow injuries to the brain and fractures of the skull involving the olfactory nerves.

Injury to nose The commonest injury is a fracture of the nasal bones or displacement of the cartilage that forms the bridge of the nose. The nasal SEPTUM may also be displaced sideways by a lateral blow. Sporting activities, especially boxing and rugby football, are commonly a cause of nasal injury. If a fracture is suspected, or if there is substantial tissue swelling, an X-ray examination is necessary. Resetting a damaged bone should be done either immediately, before swelling makes surgery di?cult, or ten days or so later when the swelling has subsided. Results are usually good, ensuring a clear airway as well as a restored pro?le. It is not unusual for the cheek-bone to sustain a depressed fracture at the same time as the nose is broken. Careful assessment and prompt surgery are called for. (For more information on fractures, see under BONE, DISORDERS OF).

Rhinitis In?ammation of the MUCOUS MEMBRANE lining the nose. Symptoms include nasal discharge and obstruction, sneezing and sometimes pain in the sinuses. There are several types of rhinitis:

•Allergic – due to allergy to dust, pollen or other airborne particles. Also called hay fever, allergic rhinitis causes a runny nose, sneezing and local congestion. It affects up to 10 per cent of the population and is more common in people suffering from other allergic disorders such as asthma or eczema (see DERMATITIS). Skin tests help to identify the causative ALLERGEN which the sufferer can then try to avoid, although in the case of pollen this is di?cult. Decongestant drugs, ANTIHISTAMINE DRUGS, and CORTICOSTEROIDS may help, as can SODIUM CROMOGLYCATE inhaled regularly during the pollen season. A desensitisation course to a particular allergen sometimes provides long-term relief.

Atrophic rhinitis is caused by a deterioration in the nasal mucous membrane as a result of chronic bacterial infection, nasal surgery or AGEING. Symptoms include persistent nasal infection and discharge and loss of sense of smell. ANTIBIOTICS and, in some cases, OESTROGENS alleviate the symptoms.

Hypertrophic rhinitis results from repeated nasal infection, and is characterised by thickened nasal membranes and congestion of the nasal veins. Removal of thickened mucosa may help severe cases.

Vasomotor rhinitis occurs when the mucosa becomes oversensitive to stimuli such as pollutants, temperature changes or certain foods or medicines. It may occur as a result of emotional disturbances and is common in pregnancy.

Viral rhinitis occurs as a result of infection by the common cold virus; treatment is symptomatic. Sinusitis is sometimes a complication.... nose, disorders of

n. reduction in the sense of smell. See anosmia.... hyposmia

a familial condition that is the most common form of isolated *gonadotrophin deficiency; it is combined with underdevelopment of the olfactory lobes, causing *anosmia. The syndrome is caused by a gene *deletion on the short arm of the X chromosome. Patients often present with delayed puberty. There is an association with *ichthyosis, learning disabilities, obesity, renal and skeletal abnormalities, and undescended testes, but these features are very variable. [F. J. Kallmann (1897–1965), US geneticist]... kallmann’s syndrome

The body system that gathers and stores information and is in overall control of the body.

The brain and spinal cord form the central nervous system (CNS), which consists of billions of interconnected neurons (nerve cells). Input of information to the CNS comes from the sense organs. Motor instructions are sent out to skeletal muscles, the muscles controlling speech, internal organs and glands, and the sweat glands in the skin. This information is carried along nerves that fan out from the CNS to the entire body. Each nerve is a bundle consisting of the axons (filamentous projections) of many individual neurons.

In addition to the nervous system’s anatomical divisions, there are various functional divisions. Two of the most important are the autonomic nervous system, concerned with the automatic (unconscious) regulation of internal body functioning, and the somatic nervous system, which controls the muscles responsible for voluntary movement.

The overall function of the nervous system is to gather and analyse information about the external environment and the body’s internal state, and to initiate appropriate responses, such as avoiding physical danger.

The nervous system functions largely through automatic responses to stimuli (see reflex), although voluntary actions can also be initiated through the activity of higher, conscious areas of the brain.

Disorders of the nervous system may result from damage to or dysfunction of its component parts (see brain; spinal cord; neuropathy; nerve injury). They may also be due to impairment of sensory, analytical, or memory functions (see vision, disorders of; deafness; numbness; anosmia; agnosia; amnesia), or of motor functions (see aphasia; dysarthria; ataxia). ... nervous system