2nd order laboratory parameters – depending on the results of the history, physical examination and obligatory laboratory parameters – for differential diagnostic clarification.
- Inflammatory parameters – CRP (C-reactive protein).
- Small blood count – e.g., if Plummer-Vinson syndrome is suspected.
- Throat swab – if bacterial pharyngitis is suspected [Note: about 50-80% of pharyngitis is caused by viruses! A throat swab is justifiable from a medium Centor score, see below “Physical examination”]
- Tonsil smear for pathogen and resistance or rapid test for group A beta-hemolytic streptococci (GABHS); compared with culture, this has a specificity (probability that actually healthy persons who do not have the disease in question are also recognized as healthy in the test) of 95%, while the sensitivity (percentage of diseased patients in whom the disease is detected by the use of the test, i.e., a positive test result occurs) is significantly lower at 70-90%.
Specimen collection: press down the tongue with a spatula and pass the swab under vision “rubbing-turning” over both tonsils (pharyngeal tonsils) or the lymphatic side strands and the posterior pharyngeal wall.
- Serology in pharyngitis/pharyngitis:
- Antibodies against adenoviruses, coxsackie viruses, ECHO viruses, influenza A and B viruses, chlamydia, Epstein-Barr virus (EBV), streptococcus (ASL), parainfluenza viruses, respiratory syncytial virus (RSV).
- Mononucleosis rapid test – for suspected mononucleosis (mononucleosis), which is associated with whitish coatings and lymphadenopathy (lymph node enlargement).
- Determination of SS-A and SS-B antibodies in suspected Sjögren’s syndrome.
Therapy of GABHS pharyngitis see under ” pharyngitis (pharyngitis)”.