Upper respiratory tract infections are frequent illnesses in the general population. They are caused by either viruses or bacteria. A viral infection may become complicated subsequently by bacteria. The location of the disease dictates its gravity, as viral upper respiratory tract infections range from simple ones, like viral nasopharyngitis to more severe ones, like rhinosinusitis, epiglottitis, laryngotracheitis and otitis media.
In viral nasopharyngitis patients have profuse nasal discharge , fever, halitosis, mouth breathing leading to dry mouth, hyposmia, sneezing and odynophagia, symptoms that occur 2-3 days after inoculation and last for 7-14 days, depending on the age of the patient . Nasal secretions are initially clear and after 2-3 days turn green or yellow, which may signify a superimposed bacterial infection . Examination of the uvula and posterior pharynx reveals inflammation. Cough may result from postnasal drip. Conjunctivitis and photophobia may accompany ocular pain.
Viral rhinosinusitis  is also characterized by nasal discharge with mucopurulent secretion that does not improve with decongestants or antihistamines administration. Facial or dental pain related to the affected sinus raise rhinosinusitis suspicion. Other symptoms include sore throat, dry mouth, cough, posttussive emesis, hyposmia, and fatigability.
Epiglottitis may represent a potential lethal emergency . It is characterized by an acute onset of symptoms like fever, dyspnea, fatigability, odynophagia- as severe as to prevent saliva swallowing, leading to drooling, dysphonia or total voice loss . Severe episodes are accompanied by respiratory distress, manifested as tachypnea, tachycardia, perioral cyanosis and use of accessory respiratory muscles.
Acute viral otitis media also has a rapid onset , consisting of fever, otalgia, difficulty sleeping, irritability, headache, loss of appetite, fluid drainage from the ear and diminished hearing .
All viral upper respiratory tract infections can cause cervical lymphadenopathy. Specific etiologies lead to specific signs: mononucleosis is accompanied by splenomegaly and hepatomegaly, herpes virus infection causes palatal vesicles, vesicles located on the uvula, palate and anterior tonsillar pillars suggest herpangina. Tonsil hypertrophy is a common finding. Cough may be severe enough to produce conjunctival hemorrhages.
The diagnosis of viral upper respiratory tract infection is mostly clinical, but several tests may also be helpful. For instance, the physician may order influenza rapid test, Epstein-Barr heterophile antibody test, cell culture for herpes simplex virus identification  or polymerase chain reaction in order to detect the same type of infection. Epiglottitis can be diagnosed by direct visualization during laryngoscopy, provided that the patient's clinical status allows it. The microbiological specimen is obtained from throat or nasal swabs or washes; they are cultured on special media in order to identify respiratory syncytial virus, influenza and parainfluenza virus and adenovirus. Antibody titers should be observed in a dynamic manner.
The complete blood cell count shows lymphocytosis in acute viral infections, but lymphopenia may also be noticed in some cases. A high white blood cell number is not unusual. In case dyspnea is noticed, foreign body inhalation should be excluded using imaging methods. In croup, the steeple sign representing subglottic stenosis may be noticed . In acute viral otitis media, tympanometry may be useful.