A 25-year-old man sustains bilateral femoral shaft fractures in a road traffic accident. Forty-eight hours later he becomes drowsy and tachypnoeic, and a rash is noted in the axillae and over the anterior chest wall. Arterial blood gas shows hypoxaemia. The single most specific clinical feature supporting the diagnosis in this patient is:

• A Petechial haemorrhages over the chest and axilla ✓
• B Tachypnoea with hypoxaemia
• C Altered sensorium
• D Pyrexia of 38 degrees Celsius

Explanation

Fat embolism syndrome follows long bone fractures, typically presenting 24 to 72 hours later with the Gurd triad of respiratory distress, cerebral disturbance and a petechial rash. Petechiae occur in only about half of patients, making them the most specific component of the triad. Tachypnoea, confusion and fever are nonspecific and occur with many post-traumatic complications such as pulmonary embolism, sepsis and head injury, so they cannot confirm the diagnosis alone.

Reference: Rockwood and Green's Fractures in Adults, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.