Sore throat and the Centor criteria

What it is

Upper respiratory tract infection covers the common cold (coryza), sore throat (pharyngitis, including tonsillitis), acute otitis media, and sinusitis, which is relatively uncommon. Tonsillar erythema and exudate are neither sensitive nor specific, so the modified Centor score, also known as McIsaac, is used to direct decision making about group A streptococcal infection. It is built from four clinical items, each worth one point: first, absence of cough; second, a history of fever >38°C; third, tonsillar exudate; fourth, swollen tender anterior cervical nodes. Age is a fifth item of a different kind, which adds a point, adds nothing, or takes one away.

Causes and risk

Viral pathogens are the most common cause, in kids and adults; viral infections account for around 90% of all sore throats, and the most common viruses are those of the common cold and the flu. Acute pharyngitis is commonly viral: rhinoviruses, influenza, and adenovirus, which causes pharyngo conjunctival fever, that is URTI with conjunctivitis. The bacterial causes named are GAS and diphtheria. In acute tonsillitis the most common organism is Streptococcus, and GAS infection has a peak incidence at age 5-12.

A sore throat may be worse at night from dehydration, from snoring, where people who snore loudly or frequently may have obstructive sleep apnea, or from allergies with nasal congestion and postnasal drip.