Allergies among Greeks have soared over the past 18 years, as one in four people is expected to suffer from some sort of dermatological or respiratory reaction, medical experts said yesterday. At a conference held in Hania, Crete, doctors said that in 1988 about 8 to 10 percent of those surveyed showed symptoms of an allergy, while the figure has now shot up to 30 percent of the population. The main causes behind allergic reactions are hereditary traits and air pollution levels, doctors said. Hay fever ranks among the most common problems, affecting 20 to 25 percent of the general population, particularly in the spring or fall seasons. Doctors pointed out that in most circumstances allergies are not considered to be a threat to health. According to the results of a study made public last month, almost one-third of residents in Athens suffer from allergies, compared to 22 percent in other Greek cities and only 15 percent in the countryside.