Anosmia

Anosmia is the complete loss of the ability to smell (olfaction), and can be temporary or permanent. Similarly, some patients may be anosmic from birth (congenital anosmia); whereas in others, it is acquired.

It is also possible for patients to be anosmic for a particular odour; in which case the condition is known as “specific anosmia”.

Temporary loss of smell can often be caused by nasal congestion, or an infection. Conversely, permanent anosmia might be due to the degeneration of neurons in the nose needed to detect odours, or damage to the olfactory nerve within the brain.

Since the inability to smell is not directly life-threatening, some medical practitioners tend to regard patients’ complaints regarding anosmia as being trivial or unimportant. The problem with this, however, is that the patient’s consequent inability to detect smells such as gas leaks, expired food products and unusual bodily odours may have serious implications. Further, in rare cases, anosmia may be caused by esthesioneurobastoma – a cancerous tumour located either within or adjacent to the olfactory nerve.

Anosmia can impact heavily on many aspects of patients’ lives, although congenital anosmics are typically less susceptible. For example, the close link between the senses of smell and taste means that some anosmics lose their appreciation of favourite foods, which can be saddening. The loss of an established smell memory of sentimental significance for a patient can also contribute to feelings of depression.