Extreme thrombocytosis under the treatment by amoxicillin/clavulanate

Amoxicillin/Clavulanate related extreme thrombocytosis during the treatment of pneumonia has never been reported. We present a 54-year-old patient who was admitted due to pneumonia, and was treated with amoxicillin/clavulanate IV and 3-day course of 500 mg azithromycin. Despite clinical and radiological evidence showing that pneumonia improved, thrombocytes increased rapidly. After stopping the antibiotic, the thrombocytes returned gradually to normal. Considering the clinical course, we propose that this extreme thrombocytosis was caused by the administration of amoxicillin/clavulanate. We describe this rare and unique patient and review the literature.