In recent weeks we have seen an increase in patients who present with ‘sore throat’ in the clinic. Some of which have subsequently been diagnosed with Scarlet Fever(SF). The Department of Health has also issued a warning to doctors to be aware of increase in number of cases of confirmed Scarlet Fever in Hong Kong.
SF is a bacterial infection caused by Group A Streptococcus (GAS). The streptococcal bacteria is transmitted through the respiratory route or direct contact with infected respiratory secretions. Initially patients present with a combination of symptoms which include sore throat, headache and temperature. Subsequently a rash usually starts on the chest or tummy, before spreading to other areas. The rash follows 12-48 hours after the fever. It starts as some pink red blotches and feels like sandpaper. The tongue initially has a white coating but then peels away leaving the tongue look red and swollen (known as strawberry tongue)
The diagnosis of Scarlet Fever is usually made clinically, however throat swabs can be taken to test for Group A strep. At The London, a rapid test for Strep A can be done onsite, with results available after 10 Minutes and therefore antibiotics started immediately. Alternatively, throat swabs can also be taken to be sent off to the laboratory to test if sore throat is due to bacterial infection, in which case the most suitable antibiotic is then advised. Results for this can take up to 3-4 days. Treatment is aimed at relieving symptoms for the patient and preventing complications such as tonsillar abscess formation, spread of infection to chest and brain, Rheumatic fever, and acute kidney injury.