Olfactory disorder or olfactory dysfunction refers to any disorder related to the sense of smell. This can involve hypersensitivity to certain odors as well as a decreased ability to smell.
What is an olfactory disorder?
Schematic diagram showing the anatomy of the nose and the olfactory nerves. Click to enlarge. Medicine basically distinguishes between three types in an olfactory disorder: on the one hand, there are patients who suffer from so-called hyperosmia – this is the name given to a hypersensitivity to certain odorants. The opposite is hyposmia – in this symptom there is an insensitivity to certain stimuli. A clear restriction of the sense of smell up to the complete loss of the smelling ability again is called in the technical language also Anosmie. All these three types of olfactory disorders are roughly summarized as quantitative olfactory disorders. On the other hand, there are the qualitative olfactory disorders – this is the term used to describe altered perceptions of a scent. Patients suffering from such qualitative disorders either perceive odors although they are not present at all or perceive existing odors in a strongly altered way. Olfactory disorders are quite widespread in Germany – after all, about 80,000 people go to the doctor every year because of an altered sense of smell.
Causes
The causes of olfactory disorders are basically divided into sinunasal and non-sinunasal causes. The former are mostly due to diseases of the nose or sinuses. Non-sinunasal causes, on the other hand, usually involve damage to the olfactory system. In the case of allergies or polyps, for example, there is often a change or even a failure of the olfactory system – only in rare cases is a serious disease such as a brain tumor behind the disorders. Even anatomical irregularities such as a crooked nasal septum or other malpositions can cause the olfactory system to be restricted or altered. Non-sinunasal causes of this symptom include side effects of medications, head injuries, or contact with a wide variety of irritants. Pregnant women also frequently complain of a reduced or altered sense of smell – but once the child is born, these symptoms usually disappear of their own accord. In Alzheimer’s disease, an olfactory disorder also occurs very frequently – after all, about 80 to 90 percent of Alzheimer’s patients are affected by olfactory disorders.
Symptoms, complaints and signs
An olfactory disorder can cause a variety of symptoms, depending on its type and severity. Typically, dysosmia results in a noticeable decrease in the sense of smell. The affected person can no longer perceive certain odors or can perceive them only faintly, and often certain odors are perceived as unpleasant. Phantosmia is manifested by the perception of odors that are not present. In parosmia, familiar odors are perceived differently and are perceived as unpleasant or irritating. Pseudoosmia is accompanied by a reinterpretation of odors. This unconscious “mis-smelling” is usually associated with further mental discomfort. In the case of olfactory intolerance, the affected person reacts very sensitively to odors; in most cases, psychological causes are also the basis. In the case of a quantitative olfactory disorder, fragrances have a stronger or lesser effect than usual. Depending on its form, quantitative olfactory dysfunction may be associated with a complete loss of the ability to smell or with the development of tolerance to certain fragrances. In most cases, the sense of smell is severely reduced and the affected person is much less able to perceive scents. What the various olfactory disorders have in common is that they are no longer perceived as such after some time. Quickly a habituation sets in and the absence of smells is concealed, for example, by over-seasoning food or using excessive amounts of deodorant.
Course
In many of the patients, the odor disorder disappears on its own within a few days. In other people, however, comprehensive examinations are necessary to first clarify the exact causes.Accordingly, treatment is then also difficult in these patients and the odor disorder can drag on for weeks or even months or even become chronic.
Complications
The olfactory disorder itself is not a complication and does not negatively affect the patient’s health. Therefore, life expectancy is not reduced with an odor disorder, and no other symptoms or complications occur with this disease. However, the disorder reduces the quality of life and makes the patient’s daily life more difficult. Likewise, it is no longer possible to enjoy food and liquids in the usual way. In the worst case, the olfactory disorder can lead to death in dangerous situations if certain dangers cannot be detected due to the lack of a sense of smell. Furthermore, the olfactory disorder can also lead to psychological complaints and depression. The affected person is socially excluded or ashamed of his disease. Treatment of the olfactory disorder is only possible to a limited extent. In many cases, the affected person has to spend his entire life with the disorder. However, treatment with the help of antibiotics or zinc can be carried out. Whether this will be successful, however, cannot be predicted. Life expectancy is not affected by the odor disorder and is not reduced.
When should one go to the doctor?
In many cases, odor disorder does not cause significant problems in everyday life. Nevertheless, people who suffer from an impairment in smelling should always see a doctor. If the changes are only minimal in direct comparison to fellow human beings, a visit to the doctor is recommended in order to determine the cause and to be able to assess the course of the disease. A detailed explanation of the disease and discussion of warning signals are essential to avoid a life-threatening condition in everyday life. If the impairments increase, consultation with a physician is necessary. If shortness of breath, interruptions in breathing or the development of anxiety occur, a physician should be consulted. If the anxiety triggers behavioral changes, social withdrawal or social phobia occurs, a doctor’s consultation is necessary. If there is pain of the head, a feeling of pressure in the head, a runny nose or nosebleeds, it is advisable to consult a doctor. In case of a stuffy nose, nasal speaking or swelling in the nose, a doctor should be consulted. If the affected person suffers from dizziness, nausea or vomiting, a doctor is needed. In isolated cases, a sudden acute condition of health concern occurs. In these cases, an ambulance must be called so that there is no threat to life.
Treatment and therapy
To ensure efficient treatment, the doctor will first ask the patient in detail about the extent of the condition. Above all, it is important to know how exactly the type of olfactory disorder manifests itself or whether other complaints such as a disturbance of the sense of taste are also present. The doctor will then examine the nose, including the olfactory cleft and pharynx, in detail. Olfactory tests can usually provide more precise information about the type of olfactory disorder in question – although in some patients, comprehensive neurological examinations are also necessary. The therapy usually depends on the underlying cause. In the case of an anatomical change, such as a crooked nasal septum as the cause of the olfactory disorder, this can easily be corrected surgically. In the case of other causes, however, treatment can be quite difficult. If hormonal causes underlie the disorder, hormone replacement may help. Steroids, zinc and antibiotics are also often used – but the extent to which these can really help against odor disorders is still largely unexplored and controversial. Lucky can count themselves the patients with whom the odor disorder disappears within a few days by itself again.
Outlook and prognosis
The prognosis for an olfactory or smell disorder depends on whether it is a temporary disorder of the sense of smell or a permanent olfactory disorder or a complete loss of the sense of smell. The olfactory disorder is a complex problem. This has a better prognosis especially in younger people. Unfortunately, the previous therapeutic approaches are not always successful.In addition, age-related olfactory disorders are just as untreatable as a congenital olfactory disorder. It is known that about two thirds of all patients who experience olfactory disorders after a viral infection experience spontaneous improvement. In one third of patients, the olfactory disorder remains permanent. The prognosis is quite good if drugs or pollutants have triggered the olfactory disorder. In most cases, the disorders regress when the medication is discontinued. In the case of pollutant exposures, avoidance of the triggering substance must be achieved for the prognosis to improve. Odor disorders often occur after severe sinu-nasal infections and diseases of the respiratory system. As soon as treatment takes effect, the symptoms disappear in many cases. The situation is different when olfaction is a result of head injury or surgery. In these cases, the prognosis may be positive for only a small proportion of those affected. The conditions for complete recovery vary from individual to individual and depend on the causes.
Prevention
There is hardly any direct prevention against the odor disorder. However, if one already suffers from it and knows the exact cause, one can at least try to contain it. If, for example, medications are the trigger for the olfactory disorder, it is advisable to switch to a different medication.
Aftercare
Direct options for aftercare are usually not possible for an olfactory disorder. It cannot be universally predicted whether the odor disorder can be completely cured. First and foremost, affected individuals rely on medical treatment from a physician to prevent further complications. The way in which this disorder is treated depends very much on the exact cause. In some cases, medication or antibiotics can be used to treat the condition. In this case, the affected person must always ensure that the medication is taken regularly. Parents must also ensure that their children take the medication regularly. Antibiotics should not be taken together with alcohol, otherwise their effect will be weakened. In some cases, the odor disorder disappears on its own, so no direct treatment or follow-up is necessary. However, it can also occur throughout life. If a particular substance is responsible for the odor disorder, it must of course be avoided. In many cases, contact with other sufferers of the disorder is also useful, as an exchange of helpful information can occur. The life expectancy of the patient is not limited by this disorder.
What you can do yourself
In everyday life, special care should be taken with an olfactory disorder. Targeted measures for a cure or relief of the symptoms can not be taken by the affected person. The focus for the sufferer should be on preventing further discomfort and avoiding health hazards. Places where toxins may be inhaled should be left immediately. Food should only be consumed if it has been purchased commercially and it can therefore be ruled out that the toxic or incompatible. Due to the lack of smelling, an important warning signal in case of danger has failed in the person concerned. As a result, foodstuffs should only be consumed abroad after consultation with and safeguarding by local experts. In this way it can be ensured that they are edible. The consumption of foodstuffs whose best-before date has expired should be avoided. If the cold chain has been interrupted in the case of fresh dairy products, meat or sausage products, they should always be disposed of. Unusual discoloration on the food is also an indication of inedible goods. Staying in closed rooms or garages with exhaust fumes, chemicals or paints is a danger zone. In these cases, it is helpful to have an accompanying person who can point out a possible risk of poisoning in good time. In addition, it is advisable to wear a mouth guard in the designated rooms.
