Purpura Fulminans in a Well Appearing Child

Introduction: Purpura fulminans describes a rapidly progressive disorder characterized by necrotizing hemorrhagic lesions of the skin. Postinfectious purpura fulminans is a rare condition, associated with features of disseminated intravascular coagulation. In children, this condition typically appears following viral infection.

Case Presentation: A healthy four-year-old boy presented with new skin lesions on his thighs and left flank. He was well appearing, with normal vital signs and otherwise unremarkable physical examination. Laboratory investigations showed normal CBC and chemistry, C-reactive protein was mildly elevated. Coagulation studies were normal, except for abnormal prothrombin time (57, normal 75-120 (%)). After few hours, a new lesion appeared on the buttock. Additional laboratory tests showed mild thrombocytopenia, hypofibrinogenemia (41 mg/dl, normal 200-400), elevated D-dimer level (52339 ng/ml, normal 0-250) and prolonged thrombin time (26 sec, normal 13-18). Given a working diagnosis of disseminated intravascular coagulation and purpura fulminans a workup for hypercoagulable states were obtained and empirical treatment with Fresh Frozen Plasma as well as Enoxaparin was initiated. Several hours following treatment, there were no new lesions and laboratory tests improved. Further evaluation revealed low levels of Protein S. Virology workup was positive for para-influenza. Due to complete clinical and laboratory recovery, a diagnosis of postinfectious purpura fulminans was made.

Conclusion: This case underscores the importance of a high index of suspicion for postinfectious purpura fulminans in a well appearing child with purpuric lesions and abnormal coagulation functions.