Abstract

A 20–year old student presented following a witnessed GTCS. In the preceding 2 years he had suffered 2 possible seizures and had a history of childhood epilepsy, temporarily treated with Carbamazepine between ages 3 and 7. A&E staff documented GCS 12 and a non–blanching, erythematous, macular rash on his face, neck and upper torso. He was started on IV Ceftriaxone for suspected meningococcal meningitis. Blood results including FBC and CRP were normal. He was apyrexial. Lumbar puncture performed 23 hours later showed normal protein and glucose, 1 lymphocyte, negative gram stain. Serum/CSF meningococcal PCR was requested. Neurology review identified GCS 15, mild headache, photophobia and no neck stiffness. The rash was petechial in nature and was most intense in the periorbital and cervical regions. It was present to a lesser extent on both cheeks, upper torso and shoulders.

He also had “carpet burn” on his right cheek. MRI brain showed mild right hippocampal malrotation, the most likely cause of his seizures. Vasculitic screen was negative. After completion of 7 days Ceftriaxone he was discharged home. Meningococcal PCR was reported negative on day 9. Theoretically meningococcal PCR should not be affected by early antibiotic treatment. The rash had faded rapidly and was only very minimally present on discharge. Based on the unusual distribution of the rash we felt it was unlikely due to meningococcal septicaemia. Thoracocervicofacial purupura has been described secondary to Valsalva manoeuvre during GTCS,^1–3 vomiting,⁴ coughing,⁵ weight–lifting⁶ and endoscope–induced wretching.⁷ This rash has been referred to as ‘mask phenomenon’ given its distribution.⁴ The underlying mechanism is thought to be increased intrathoracic pressure causing decreased venous return to the heart and reflux from the right atrium into the valve–less superior vena cava. The resultant venous congestion in the distribution of the SVC causes increased transmural pressure in the capillaries and extravasation of red blood cells.⁸

Excluding meningococcal rash can be a difficult task; however the localised distribution of thoracocervicofacial purpura following a seizure can be a reassuring sign for patients and the medical team.