From the Guidelines
The key physical finding in strep throat is erythematous (red) pharyngeal mucosa with white or yellow exudates on the tonsils, and other common findings include petechiae on the soft palate, uvular edema, anterior cervical lymphadenopathy, and sometimes a scarlatiniform rash. Patients typically present with fever, sore throat, pain with swallowing, and absence of cough or rhinorrhea. The presence of palatal petechiae and scarlet fever rash are particularly specific for Group A Streptococcal infection. These physical findings, known as Centor criteria (fever, tonsillar exudates, tender anterior cervical lymphadenopathy, and absence of cough), help clinicians determine the likelihood of strep throat and guide testing decisions 1. However, no single physical finding is pathognomonic, so definitive diagnosis requires either a rapid strep test or throat culture. The physical examination is important because it helps distinguish bacterial pharyngitis from viral causes, which typically present with conjunctivitis, cough, rhinorrhea, and more diffuse pharyngeal erythema without exudates.
Some of the key points to consider when evaluating a patient with suspected strep throat include:
- The patient's age, as strep throat is more common in children between 5 and 15 years old 1
- The presence of fever, sore throat, and pain with swallowing, which are common symptoms of strep throat 1
- The absence of cough or rhinorrhea, which can help distinguish strep throat from viral causes 1
- The presence of petechiae on the soft palate or scarlet fever rash, which are specific for Group A Streptococcal infection 1
It's also important to note that diagnostic testing is not recommended if clinical features strongly suggest a viral etiology, and follow-up posttreatment testing is not routinely recommended 1. The most recent guidelines recommend penicillin or amoxicillin as the first-line treatment for strep throat, due to their narrow spectrum of activity, few adverse effects, and modest cost 1. Alternative antibiotics may be considered for patients with penicillin allergy.
From the Research
Physical Findings of Strep Throat
The physical findings of strep throat include:
- Sore throat
- Temperature greater than 100.4 degrees F (38 degrees C) 2
- Tonsillar exudates
- Cervical adenopathy (tender anterior cervical adenopathy) 3, 2, 4
- Pharyngeal or tonsillar exudate 4
- Tender enlarged anterior cervical lymph nodes 4
Differentiating Strep Throat from Viral Pharyngitis
Viral pharyngitis often presents with additional symptoms such as:
- Cough
- Coryza
- Conjunctivitis
- Diarrhea 2, 4 The presence of these symptoms suggests a viral cause rather than strep throat.
Diagnostic Criteria
The modified Centor score can be used to help physicians decide which patients need no testing, throat culture/rapid antigen detection testing, or empiric antibiotic therapy 3, 2, 4. A diagnosis of pharyngitis is supported by the patient's history and by the physical examination. Throat culture is the gold standard for diagnosing streptococcus pharyngitis 4.