Severe Ecthyma Gangrenosum in a Pediatric Patient With Neutropenia and a Novel HELLS Variant: Case Report.

Ecthyma gangrenosum (EG) is a rare and severe skin infection typically caused by Pseudomonas aeruginosa, often seen in immunocompromised patients. This report describes a case of a 19-month-old boy who presented with high-grade fever, diarrhea, vomiting, and skin lesions over 5 days. Examination revealed respiratory distress, fever, tachycardia, hypotension, delayed capillary refill, and multiple erythematous skin lesions. Laboratory workup revealed pancytopenia with severe neutropenia and elevated inflammatory markers. The patient was started on empirical meropenem and vancomycin and later switched to cefepime after cultures identified pan-susceptible Pseudomonas aeruginosa. He required multiple transfusions and fresh frozen plasma for coagulopathy. Whole-exome sequencing identified a novel HELLS variant (c.1904G>A; p.Cys635Tyr), classified as a variant of uncertain significance. This case underscores the diagnostic and management challenges of EG, highlighting the importance of early recognition and a multidisciplinary approach.