Don’t prescribe blood exams in children with acute pharyngitis.

Type of practice

Laboratory tests

Topic Area


Blood tests, including inflammatory markers, are not useful in differentiating bacterial from viral pharyngitis because they can also be increased in some viral infections. Antistreptolysin O titer and anti-DNAse antibodies are useful for the diagnosis of poststreptococcal complications, such as rheumatic fever and glomerularnephritis, both occurring some weeks after the acute streptococcal infection. They are not of help for the diagnosis at the time of an episode of acute pharyngitis.


1. Chiappini E et al. Management of acute pharyngitis in children: summary of the Italian National Institute of Health guidelines. Clin Ther 2012; 34: 1442-58.
2. Choby BA. Diagnosis and treatment of streptococcal pharyngitis. Am Fam Physician 2009; 79: 383-90.

Attention. Please note that these items are provided only for information and are not intended as a substitute for consultation with a clinician. Patients with any specific questions about the items on this list or their individual situation should consult their clinician.