What is that rash?

CASE HISTORY

A healthy 15-month-old girl presented to the emergency department with a 24-hour history of fever and rash. The initial blanching rash developed into non-blanching areas with associated leg swelling. She had received no recent medications, had no known drug allergies and no unwell contacts.On examination, she was feverish at 38.6°C, capillary refill time was <2 s with warm peripheries, heart rate 169 bpm and blood pressure 94/59 mm Hg. A palpable purpuric rash was evident on all four limbs and face (figure 1) although the trunk was spared. Her legs were tense and oedematous to the knee.edpract;103/1/25/EDPRACT2016311782F1F1EDPRACT2016311782F1Figure 1Rash at presentation.Initial investigations: Haemoglobin level: 131 g/L, white cell count: 16.6×10/L, neutrophils: 11.1×10/L and platelets: 407×10/LCoagulation screen: normalC reactive protein level: 20 mg/LLactate level: 1.7 mmol/LIntravenous ceftriaxone was commenced following blood culture and meningococcal PCR. The following day, while remaining systemically well, she developed a vesicular rash on her trunk and back (figure 2).edpract;103/1/25/EDPRACT2016311782F2F2EDPRACT2016311782F2Figure 2Vesicular rash.

QUESTIONS

What is the diagnosis? Henoch-Schonlein purpura (HSP)Meningococcal septicaemiaAcute haemorrhagic oedema of infancy (AHOI)Vasculitic urticariaGianotti-Crosti syndromeWhat further investigation is required? Check viral serology including Epstein-Barr virus and hepatitis B virusComplement levels and autoimmune screenSkin biopsyLumbar puncture and audiologyNo further investigationHow should this child be managed? Complete 7 days of ceftriaxone treatmentOral aciclovirOral steroidsRegular follow-up with urinalysis and blood pressure monitoringStop antibiotics if cultures were negative at 48 hours and discharge▪▪.