[Dysgeusias].
This is a review of multiple pathologic conditions associated with altered taste perception and identification. We stated the steps and the molecular basis of this sense. This paper includes two cases that exemplify two distinct types of dysgeusia; case, 1 a 48 year old man who had clinical manifestations of hypogeusia and dysgeusia for one year, probably secondary to air pollutants. Case 2, a 37 year old man who worked in the same factory and also had dysgeusia; we concluded that it was secondary to thermal and chemical agression of the oropharynx; his plasma and urinary levels of zinc were normal. Many medications and contaminants of air and water are related with changes in serum and urine levels of zinc, which is a determinant at several levels for the correct integration of the taste system. Namely it is important for synthesis of the metalloprotein, gustin, a parotid gland protein secreted into saliva, which in turns is very important to make union of the sapid substance (SS) with its receptor in the surface of the gustatory epithelium a the taste buds. Zinc is also related with neurotransmission of the electrical stimulus generated in the bud cell and ending in the central nervous system. There is an acute zinc loss syndrome, seen in patients treated with histidine, which simulates the steps in which taste sensation is integrated. A clinical approach for diagnosis of hypogeusic or dysgeusic patients must include a careful evaluation of the diat elements, an assesment of hereditary disorders, the type of work and contact with pollutants known to be related with dysgeusia. A special care regarding physical examination must be considered in particular a meticulous review of the oropharynx in order to diagnose inflammatory, neoplastic or neurological disorders. The levels of perception an identification of flavors: sweet, bitter, sour and salt, must be determined using the forced scale triple choice technic. Serum and urinary levels of zinc should be determined in each patient using a flameless atomic absorption spectrophotometer. A quantification of the activity of leucocyte alkaline phosphatase, a zinc metalloenzyme, is a useful aid, liver function tests. 13 and 14 determinations and serum protein electrophoresis are mandatory because many pathologic states of these organ systems are known to be related with disorders of taste. We wish to remark the important function of zinc in the taste system, the role of essential trace elements is receiving increased atention and these alterations are good examples of their clinical importance.