4. It will be considered symptoms of the common cold the presence of at least 2 of the 10 symptoms following: runny nose, sneezing, nasal congestion, headache, myalgia, throat discomfort or sore throat, hoarseness, cough or fever. Each of the symptoms listed above will receive a score by Likert scale (no symptom = 0, mild symptoms = 1, moderate symptoms = 2, intense symptoms = 3). The minimum total is 0 and maximum one is 30, which included patients with score higher or equal to 4 points.