Which of the following indicates a need for a strep test according to the Centor criteria?

The Centor criteria are used to assess the likelihood of Group A streptococcal pharyngitis in adults and provide guidance on whether to perform a strep test. The criteria include:

1. Fever (temperature > 38°C or 100.4°F)

2. Absence of cough

3. Swollen and tender anterior cervical lymph nodes

4. Presence of tonsillar swelling or exudates

According to the Centor criteria, a higher number of features is associated with a greater likelihood of streptococcal infection, thus indicating the need for diagnostic testing. When three criteria are met, the probability of a strep throat increases significantly and justifies further evaluation through a strep test. This approach aids in identifying patients who would benefit from antibiotic treatment, helping to prevent complications associated with untreated Group A strep infections, such as rheumatic fever.

In cases where fewer than three criteria are present, the recommendation typically leans towards observation and supportive care rather than immediate testing. Therefore, meeting three criteria clearly denotes a need for a strep test, aligning with the principles of effective clinical decision-making based on evidence-based guidelines.