Statistics from Altmetric.com
Editor,—Heat stroke is a potentially fatal disorder but often difficult to diagnose in children. Peripheral neutrophils with radially hypersegmented nuclei—“botryoid” neutrophils—are known to be characteristic of heat stroke in adults.1 We describe three children exhibiting botryoid neutrophils who presented with acute encephalopathy.
Patient 1 was a 7 month old girl with severe cerebral palsy who became unresponsive after being kept warm with a hot pack in winter. She was febrile (⩾ 42°C) and hypotensive, and she had several seizures and bloody stools. After supportive treatment including cooling procedures, she returned completely to her pre-illness state 14 days later.
Patient 2, a previously healthy 9 year old girl with a one day history of cough and fever was found unresponsive and convulsive in winter. Before her collapse, her mother had kept her warm with an electric foot warmer because she had complained of a chill. Her clinical picture was characterised by high fever (⩾ 42°C), shock, diarrhoea, and bleeding. Despite aggressive treatment she continued to deteriorate and was pronounced brain dead on day 4.
Patient 3 was a previously healthy 14 month old boy with a three day history of diarrhoea who presented with acute encephalopathy in summer. He had been well until three hours earlier. At presentation his temperature was 40.4°C and his blood pressure 36 mm Hg. Bleeding diathesis was outstanding on his skin and oral mucosa. Despite aggressive resuscitative measures he died 18 hours later.
Table 1 shows the laboratory findings of the three patients. In the presented blood smears neutrophils had botryoid changes of 1% (patient 1), 50% (patient 2), and 2% (patient 3) (fig 1). Patients 1 and 2 did not have botryoid neutrophils on day 2. In patients 1 and 2, all bacterial cultures were negative. In patient 3, blood culture was positive for Pseudomonas aeruginosa but no lesions of pseudomonas infection were detectable in any organs at necropsy. In patient 2, a rise in haemagglutination inhibiting antibodies against influenza virus A was detected.
Although the thermal condition was different in each case, these patients shared clinical features typically seen in heat stroke including acute encephalopathy, shock, diarrhoea, raised liver and muscle enzymes, azotemia, coagulopathy, and high fever.2Botryoid neutrophils have been observed in haemorrhagic shock and encephalopathy syndrome (HSES), which is a fulminating encephalopathy of infants and has been suggested to be the same condition as heat stroke.3 Patient 1 had the typical features of HSES. Patient 2 was rather old for HSES and patient 3 conflicted with the diagnosis of HSES because of a positive blood culture.4 These latter two patients may represent atypical forms of HSES. Heat stroke may easily be misdiagnosed as infectious encephalopathy because children, as with patients 2 and 3, frequently have clinical evidence of infection. Our observations suggests that detection of botryoid neutrophils may be helpful in the early diagnosis of heat stroke including atypical HSES in children who present with acute encephalopathy.