Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems that your son is suffering from allergic reaction as the symptoms of rashes, runny eyes and sneezing are all due to allergic reaction only and if he is being getting the symptoms at some particular place it seems to be exposure to the allergen present in that particular place.. It can be due to causes like animal danders, pollen, certain trees and grasses and can also be any food or medicine.. I would suggest you to consult an Allergist and get allergic tests like Patch test, RAST test, food challenge test etc can help in diagnosis and treatment can be done accordingly.. The tests will help in ruling out the exact cause of the allergen and once you know the cause of the allergic reaction you can avid exposure to it to prevent allergy attack.. He can be advised to take anti allergics like benadryl along with steroid nasal sprays to relieve the symptoms.. Do steam inhalations.. He can also be instilled an Immunotherapy that will help in reducing the severity and frequency of allergic attack.. Once the allergen is ruled out avoiding exposure to it can prevent the allergy symptoms.. Hope this information helps.. Regards..