In terms of pathophysiology, rhino virus infection resembles the immune response. The viruses do not cause damage to the cells of the upper respiratory tract but rather cause changes in the tight junctions of epithelial cells. This allows the virus to gain access to tissues under the epithelial cells and initiate the innate and adaptive immune responses.[7]
Up to 15% of acute pharyngitis cases may be caused by bacteria, most commonly Streptococcus pyogenes, a group A streptococcus in streptococcal pharyngitis ("strep throat").[8] Other bacterial causes are Streptococcus pneumoniae, Haemophilus influenzae, Corynebacterium diphtheriae, Bordetella pertussis, and Bacillus anthracis[citation needed].
Sexually transmitted infections have emerged as causes of oral and pharyngeal infections.[9]
Symptoms Allergy URI Influenza  headingBody  Itchy, watery eyes Common Rare (conjunctivitis may occur with adenovirus) Soreness behind eyes, sometimes conjunctivitis Nasal discharge Common Common[4] Common Nasal congestion Common Common Sometimes Sneezing Very common Very common[4] Sometimes Sore throat Sometimes (post-nasal drip) Very common[4] Sometimes Cough Sometimes Common (mild to moderate, hacking)[4] Common (dry cough, can be severe) Headache Uncommon Rare Common Fever Never Rare in adults, possible in children[4] Very common 100–102 °F (or higher in young children), lasting 3–4 days; may have chills Malaise Sometimes Sometimes Very common Fatigue, weakness Sometimes Sometimes Very common (can last for weeks, extreme exhaustion early in course) Muscle pain Never Slight[4] Very common (often severe)
In uncomplicated colds, cough and nasal discharge may persist for 14 days or more even after other symptoms have resolved.[4] Acute upper respiratory tract infections include rhinitis, pharyngitis/tonsillitis and laryngitis often referred to as a common cold, and their complications: sinusitis, ear infection and sometimes bronchitis (though bronchi are generally classified as part of the lower respiratory tract.) Symptoms of URTIs commonly include cough, sore throat, runny nose, nasal congestion, headache, low-grade fever, facial pressure and sneezing.
Symptoms of rhinovirus in children usually begin 1–3 days after exposure. The illness usually lasts 7–10 more days.[4]
Color or consistency changes in mucous discharge to yellow, thick, or green are the natural course of viral upper respiratory tract infection and not an indication for antibiotics.[4]
Group A beta hemolytic streptococcal pharyngitis/tonsillitis (strep throat) typically presents with a sudden onset of sore throat, pain with swallowing and fever. Strep throat does not usually cause runny nose, voice changes, or cough.
Pain and pressure of the ear caused by a middle ear infection (otitis media) and the reddening of the eye caused by viral conjunctivitis are often associated with upper respiratory infections.