LETTERS TO THE EDITOR Dear Editor, THROMBOCYTOPAENIA IN SYSTEMICJUVENILE IDIOPATHIC ARTHRITIS: NOT ALWAYS MACROPHAGE ACTIVATION SYNDROME! Pseudothrombocytopaenia is one of the silently puzzling nuisance to the treating physician. 1 EDTA (ethylene diaminetetraacetic acid) is a favoured anticoagulant for laboratory use as it does not distort the blood cells, but it is also known to be notorious to cause clumping of platelets. A 5-year-old boy presented with high-grade fever for 1 month and arthralgia of both knees and ankles for 5 days duration. He also had evanescent rash over trunk and neck that used to appear at the spike of fever and disappear once the fever subsides. Out- side investigation records showed polymorphonuclear leukocyto- sis (21.5 × 10 9 /L) and thrombocytosis (750 × 10 9 /L). He also had elevated erythrocyte sedimentation rate and C-reactive protein levels. Biochemical profile, serum urea, creatinine, bilirubin, ala- nine transaminase, aspartate transaminase, albumin levels were normal. Chest radiograph and ultrasound abdomen were normal. Microbiology work-up including blood cultures, urine cultures, hepatitis B surface antigen, brucella serology were negative. Viral serologies including cytomegalovirus, Epstein–Barr virus, human immunodeficiency virus, Hepatitis-C virus were negative. Work- up for tuberculosis and lupus was non-contributory. Bone mar- row examination showed reactive changes. Serum ferritin was elevated (1642 ng/mL). In view of quotidian fever and arthritis along with evanescent rash diagnosis of systemic juvenile idio- pathic arthritis was proffered after excluding other causes of fever. He was started on oral naproxen 15 mg/kg/day. However, he continued to mount high-grade fever spikes and he was also noted have thromocytopaenia (69 × 10 9 /L). On the background of systemic juvenile idiopathic arthritis, persistence of fever, anaemia, thrombocytopaenia, high ferritin and triglyceride values, macrophage activation syndrome was suspected and child was started on prednisolone 2 mg/kg/day. On prednisolone, fever and arthralgia showed prompt response, but thrombocytopaenia persisted. A repeat serum fer- ritin level value was lower (1095 ng/mL), and serum triglycer- ides, fibrinogen levels were normal. A repeat bone marrow examination was performed which showed non-specific changes and mild increase in histiocytes. Despite clinical improvement, thrombocytopaenia persisted which was not explained with any obvious cause. A peripheral smear showed marked clumping of platelets. Blood counts done with citrated and heparinized sam- ples showed normal platelet counts (4.29 × 10 9 /L, 4.05 × 10 9 /L, respectively). EDTA occasionally causes clumping of platelets possibly because of alteration of surface glycoproteins. EDTA induced thrombocytopaenia must be considered in patients with systemic juvenile idiopathic arthritis who has persistent thrombocytopae- nia despite having improving trend. Clinicians must be aware of this benign entity, as it might avoid multiple other investigations done to rule out causes for thrombocytopaenia. A peripheral smear examination is a valuable tool to identify the presence of platelet clumps due to EDTA. 2 Presence of normal platelet counts in the citrated and heparinized samples will confirm the fact that thrombocytopaenia is EDTA induced and not the real one. 3,4 Dr Rajeev Gupta Dr Dharmagat Bhattarai Dr Pandiarajan Vignesh Dr Deepti Suri Allergy Immunology Unit, Department of Pediatrics Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research Chandigarh India Conflict of interest: None declared. References 1D’Angelo G, Calvano D, Mattaini R, Cosini I, Giardini C. Platelet aggre- gation in presence of anticoagulants dependent pseudothrombocyto- penia. Minerva Med. 1993; 84: 399–402. 2 Shimasaki A, Kato T, Ozaki Y. Studies of platelet aggregation in six cases of EDTA-dependent pseudothrombocytopenia. Rinsho Ketsueki 1994; 35: 529–34. 3 Noguchi S, Kitayama M, Niwa H, Tamai Y, Hirota K. A case report of sudden thrombocytopenia detected only by in vitro analysis. J. Anesth. 2016; 30: 720–2. 4 Wu W, Guo Y, Zhang L, Cui W, Li W, Zhang S. Clinical utility of auto- mated platelet clump count in the screening for ethylene diamine tet- raacetic acid-dependent pseudothrombocytopenia. Chin Med J 2011; 124: 3353–7. Dear Editor, PRIMARY EBSTEIN-BARR VIRUS INFECTION PRESENTING WITH PROMINENT LIP AND TONGUE SWELLING A 7-year-old boy presented to the hospital with a 5-day history of fevers associated with painful lip and tongue swelling. The child was vaccinated and previously well. The illness initially started with mild bilateral conjunctivitis (spontaneously resolved) and rhinorrhoea 5 days before the onset of the fevers and lip swelling. No other skin changes or rashes were noted by the family. As the swelling of the lips and tongue became more significant, the child began to have increasing difficulty tolerating oral fluids prompting presenta- tion to the emergency department. On presentation, the child was alert with normal cardiorespira- tory vitals, although febrile to 38  C. His lips were painfully swollen with associated blistering and shallow ulceration (Fig. 1). His tongue was also swollen with doi:10.1111/jpc.14125 1052 Journal of Paediatrics and Child Health 54 (2018) 1052–1055 © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians)