Dysgeusia, also known as parageusia, is a distortion of the sense of taste. Dysgeusia is also often associated with ageusia, which is the complete lack of taste, and hypogeusia, which is a decrease in taste sensitivity. An alteration in taste or smell may be a secondary process in various disease states, or it may be the primary symptom. The distortion in the sense of taste is the only symptom, and diagnosis is usually complicated since the sense of taste is tied together with other sensory systems. Common causes of dysgeusia include chemotherapy, asthma treatment with albuterol, and zinc deficiency. Liver disease, hypothyroidism, and rarely certain types of seizures can also lead to dysgeusia. Different drugs could also be responsible for altering taste and resulting in dysgeusia. Due to the variety of causes of dysgeusia, there are many possible treatments that are effective in alleviating or terminating the symptoms of dysgeusia. These include artificial saliva, pilocarpine, zinc supplementation, alterations in drug therapy, and alpha lipoic acid. Signs and symptoms
The alterations in the sense of taste, usually a metallic taste, and sometimes smell are the only symptoms. Causes
Chemotherapy
A major cause of dysgeusia is chemotherapy for cancer. Chemotherapy often induces damage to the oral cavity, resulting in oral mucositis, oral infection, and salivary gland dysfunction. Oral mucositis consists of inflammation of the mouth, along with sores and ulcers in the tissues.
Hypoglycemia is rare in those without diabetes, because there are many regulatory mechanisms in place to appropriately balance glucose, insulin, and glucagon. Please refer to Pathophysiology section (above) for more information on glucose, insulin, and glucagon. Diabetics
Medications
The most common cause of hypoglycemia in diabetics is medications used to treat diabetes such as insulin, sulfonylureas, and biguanides. This is often due to excessive doses or poorly timed doses. Sometimes diabetics may take insulin in anticipation of a meal or snack, and missing or forgetting that meal will lead to hypoglycemia. This is due to increased insulin without the presence of glucose from the planned meal. Hypoglycemic unawareness
Recurrent episodes of hypoglycemia can lead to hypoglycemic unawareness, or the decreased ability to recognize hypoglycemia. As diabetics experience more episodes of hypoglycemia, the blood glucose level which triggers symptoms of hypoglycemia decreases. In other words, people without hypoglycemic unawareness experience symptoms of hypoglycemia at a blood glucose of about 55 mg/dL (3.0 mmol/L). Those with hypoglycemic unawareness experience the symptoms of hypoglycemia at far lower levels of blood glucose. This is dangerous for a number of reasons. The hypoglycemic person not only gains awareness of hypoglycemia at very low blood glucose levels, but they also require high levels of carbohydrates or glucagon to recover their blood glucose to normal levels.