Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which antibiotic is known to cause a rash in patients suffering from mononucleosis?

1. Amoxicillin

2. Cefuroxime

3. Erythromycin

4. Piperacillin

The correct answer is: Amoxicillin

Amoxicillin is known to cause a rash in patients suffering from infectious mononucleosis, particularly those infected with Epstein-Barr virus (EBV). In these patients, the administration of amoxicillin often leads to an eruption that is characteristically morbilliform, resembling a measles-like rash. This reaction is not an allergic response but rather a consequence of the interaction between the drug and the underlying viral infection, leading to an abnormal immune response. The occurrence of this rash is a notable clinical point, as it helps differentiate the typical reaction to amoxicillin in the context of mononucleosis from other potential drug allergies. Understanding this relationship is significant for clinical practice, as it guides healthcare professionals in making informed decisions about the appropriate use of antibiotics in patients diagnosed with mononucleosis. Other antibiotics listed, such as cefuroxime, erythromycin, and piperacillin, do not have the same well-documented association with rash in the context of mononucleosis. Therefore, they are not typically considered in discussions regarding antibiotic-related rashes in these patients.