[Acute fever with rash, necrosis, and bullae in both lower extremities in a 12-year-old girl]

A girl, aged 12 years, was admitted due to fever and rash for 3 days. The child developed recurrent high fever and rash on both lower extremities 3 days before, and the rash on left lower extremity quickly merged into a patch within 24 hours, with hemorrhage and necrosis in black and purple, large vesicles, and blisters in the center. Laboratory examination showed a reduction in platelet count and significant increases in fibrinogen and D-dimer during the course of the disease. The child was diagnosed with purpura flulminans. She was given meropenem combined with linezolid for anti-infection, injection of gamma globulin for immunoregulation, and low-molecular-weight heparin for anticoagulation. The fluid in the rash blisters was drawn and the wound was treated to prevent infection. The child's temperature returned to normal, with improvement in gangrene. She was discharged after platelet count, fibrinogen, and D-dimer had returned to normal. Purpura fulminans is a rare thrombotic hemorrhagic disease with rapid progression and is commonly seen in children. Without timely treatment, it may cause severe sequelae with high disability and mortality rates. Anti-infection, correction of coagulation function, and local management of gangrene skin are of great importance during treatment.