This report presents the case of a healed 5-month-old infant with necrotising (malignant) bilateral otitis externa from acute mastoiditis on the right side and sepsis caused by Pseudomonas aeruginosa infection. Despite of immediately performed mastoidectomy, targeted antibiotics and intensive local treatment, two third of both external auditory canal's epithelium had shown subcutaneous concentric necrosis and ejection which have been removed with repeated necretomies. After the remission of inflammatory symptoms, successful bilateral auditory canal reconstructions were performed. The observed right peripheral facial paresis at the beginning of disease remained stationary. The patient healed with residual symptoms after 2 months of treatment. Neither immune deficiency, nor diabetes could have been proven.