Oral steroids are given as the treatment. Both of these; sense of smell and taste are likely to return back and are not likely to be permanent. Loss of smell is called as anosmia. Usually sense of taste is integrally connected with it (called as Ageusia; loss of taste). Many times the cause is not ascertainable for these problems and thus treatment is difficult. Loss of smell and taste from viral and other cause need counseling as the return of these functions/senses is spontaneous. So most of the advice is what to expect and how to protect yourself from harm.
1) Gas detectors are recommended if any heating or home appliances run on natural gas. Information on where to purchase these detectors can be obtained from local gas companies.
2) Food storage should be cautious and should be avoided. Labeling leftovers with dates of storage is very important so you can dispose them appropriately.
3) If you have minimal of the nose symptoms like running or blockage, this can be underlying allergic rhinitis (even if mild in nature), because this mild disease may impair ability to appreciate any smell and taste, that does return.
Following are the other possible causes and treatment;
a) Nose or sinus condition; should be aggressively treated.
b) Hypothyroidism, diabetes if are concomitant disease, they should be managed meticulously. These conditions should be investigated for those who do not have them, by getting glycosylated hemoglobin (for diabetes) and TSH (for low thyroid/hypothyroidism), as in your case.
c) Vitamins, topical steroids, and tricyclic antidepressants (for their effect on Cerebro-Spinal Fluid catecholamines) can be tried by your physician as they are effective in 50% of cases.
d) Eliminating toxins like cigarette smoke (active or passive)
e) A viral disease can cause extensive scarring and replacement of the nerves, but studies suggest that stem cells remain, allowing for potential regeneration of the olfactory epithelium. Recovery of smell and taste can take weeks to months. Oral steroids improve function in these cases, thus should be tried by your physician for you, if not yet done.
Please feel free for your follow up questions.
Edited by Dr. Arun Phophalia on 8/6/2010 at 9:08 AM EST