Roxithromycin-associated acute thrombocytopenia

Objective: Background: Case Report: Conclusions: Unusual or unexpected effect of treatment Recently, some case reports have been published on the macrolide antimicrobials azithromycin and clarithromy-cin as the cause of thrombocytopenia. The publicly accessible databases of the European Medicine Agency and the WHO drug monitoring program contain dozens of reports of roxithromycin-associated thrombocytopenia. We described the case of a 78-year-old woman presenting to our unit with petechial lesions of the palate, 2 he-matomas of the tongue, and purpuric macules in the abdomen and in the left lower limb 4 days after a course of roxithromycin. She presented to the Emergency Department with 3 out-of-range blood test results: neutro-phils (11 960/mL; range: 1500-7000/mL), platelet count (3000/mL; range: 150 000-400 000/mL), and lactate dehydrogenase (379 IU/L; range: 135-225 IU/L). Thrombocytopenia occurred in the absence of aggregates and observed nucleolated lymphocytes. Lymphoproliferative pathologies and thrombotic microangiopathy were ex-cluded by the hematologist. To rule out neoplastic lesions, an abdominal ultrasound examination was made. Antibody screening was performed for antinuclear antibodies, extractable nuclear antigen, antineutrophil cy-toplasmic antibodies (all negative), and for Parvovirus B-19 (IgM negative, IgG positive), as well as HHV-6 and HHV-8 (both negative), to exclude an autoimmune or viral etiology. She recovered after intravenous methyl-prednisolone 60 mg/day and intravenous-immunoglobulin therapy 400 mg/kg/day. After 9 days, the patient was discharged with resolution of skin and buccal lesions. Her platelet count was 515 000/mL. To the best of our knowledge, this is the first case of roxithromycin-associated acute autoimmune thrombo-cytopenia reported in the medical literature. We suggest that clinicians should consider this drug to be among the possible causes of drug-induced thrombocytopenia.