Family Health Guide

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Sore Throat: Causes

The root cause of a sore throat is usually a viral infection like a cold or the flu. Sore throats can also be bacterial, however, which means they require antibiotics.

The cause of a throat infection varies, depending on the illness.

Strep Throat
Group A beta-hemolytic streptococcus, or GABHS bacteria, cause this throat infection. This type of bacterium is extremely contagious, and can be passed on by coughing and sneezing. It can also linger on surfaces such as doorknobs, counters and bathrooms and then enter the body through the nose or mouth.


The most common cause of tonsillitis, especially in younger children, is usually a viral infection, but it can be bacterial too. Typically, younger children have viral tonsillitis, while kids 5-18 will more likely have tonsillitis caused by group A beta-hemolytic streptococci, the same strain of bacterium that causes strep throat. The Epstein-Barr virus (which causes infectious mononucleosis), herpes virus, and measles virus can cause tonsillitis, too.


The Coxsackievirus can be transmitted through coughs and sneezes. It can also be passed person to person via saliva, fluid from the infected blisters, nose and throat fluid, and stool. It’s common in young kids and spreads quickly in school or daycare settings. 

Scarlet Fever

Scarlet fever, also known as scarlatina, is caused by group A streptococcus bacterium, also the cause of strep throat. It too is passed through coughs and sneezes, or by touching a surface infected by the bacteria.


Haemophilus influenza B (Hib) bacteria infects the epiglottis and surrounding tissue, and causes inflammation, which can potentially block your child’s airways. Hib can spread via coughs and sneezes. Less common causes of the condition are direct blows to the throat, or hot liquids or chemicals burning the epiglottis.