Objective: To report a case of Henoch-Schönlein purpura that appears to be related to the intake of clarithromycin for pharyngitis/tonsillitis.
Case summary: We describe a case of Henoch-Schönlein associated with clarithromycin therapy in a 48-year-old white man with no history of allergic drug reactions. Four days after starting therapy, he came to our hospital emergency room because of a non-pruritic palpable purpuric rash on the trunk and extremities and arthralgias involving elbows and knees. Administration of clarithromycin was suspended, in a few days, arthralgias and skin lesions quickly resolved. Three weeks later, the patient presented again with abdominal pain, dark-red urine and swelling of the legs. Urinalysis revealed proteinuria of 11 g/24 h and hematuria. A percutaneous renal biopsy showed a diffuse endocapillary proliferative glomerulonephritis with segmental areas of fibrinoid necrosis within glomeruli, on immunofluorescence study granular deposits of IgA and C3 were present in the mesangium and capillary walls. A diagnosis of HSP was made. We suspected that the causative agent might be clarithromycin since this was the only drug added before the cutaneous and renal condition appeared.
Conclusions: Our case and the previous case suggest that HSP may represent a potential adverse effect of clarithromycin, clinicians should be alerted to this potentially severe side effect of such a widely used drug. In accordance with the data obtained and based on the Naranjo algorithm, the adverse reaction could be considered possible.