This article is more than 5 years old. Information may no longer be current.
Study supports shifting diagnostic paradigm for pharyngitis
Click Here to Manage Email Alerts
Many physicians continue to overprescribe antibiotics for pharyngitis in lieu of performing appropriate diagnostic testing. This has promoted researchers from Illinois and Ohio to call for a shift from strategies that emphasize maximizing group A streptococcus identification toward one that favors limiting antibiotic exposure.
The researchers cited several previously published studies concerning screening and antibiotic use in patients with pharyngitis, including one in which clinicians performed a diagnostic test for 80% of adult patients. Although only 17% of these patients had positive test results, 47% were prescribed antibiotics.
Stratifying patients using McIsaac scores, a scale for assessing pretest likelihood of group A streptococcus using clinical symptoms, may be a valid strategy for ruling out patients who are unlikely to have these infections, subsequently reducing inappropriate antibiotic usage, according to the researchers.
McIsaac score criteria include a history of temperature >38°C, absence of cough, tender anterior cervical adenopathy, tonsillar swelling or exudates and an age younger than 15 years, with one point assigned for each present factor. Patients with more than two McIsaac factors were defined as having an increased likelihood of group A streptococcus infection.
“Limiting throat swabs to patients with scores greater than two would eliminate testing for the large proportion of patients with viral pharyngitis and some patients more likely to be group A streptococcus carriers,” the researchers wrote. – by Nicole Blazek
Pediatrics.2009;doi:10.1542/peds.2008-0488.
In most pediatric clinical practices with well-trained pediatricians, strep testing among pediatric patients with a history of sore throat is already performed with nearly identical use of McIsaac risk factors to select which patients should be tested.
As positive tests are often observed with these symptoms, I will always test for strep in patients who have significantly red pharynx (without tonsillar exudates) plus fever and/or anterior cervical gland tenderness; red, exudative tonsillitis; tender, swollen anterior cervical nodes; scarlet fever rash and many petecchiae on the soft palate. An associated rhinorrhea will not necessarily preclude strep testing in the above scenarios.
But exceptions abound, l almost never test for strep in the child with a red pharynx who has physical findings of herpangina, herpes stomatitis, croup or who is aged younger than 12 months. And yes, like the adult population described in the paper, it makes me more than a bit cranky when I see a pediatric patient from the ED or walk-in clinic for a follow-up who has a sore throat and a negative strep test (and even a normal complete blood count) who still receives an antibiotic without any other justification.
– Stan L. Block, MD
Infectious Diseases in Children Editorial Board member