Thrombocytosis in relation to severity of lower respiratory tract infection in children aged 2 months to 5 years

Background: Primary or essential thrombocytosis in children is very rare but reactive thrombocytosis occurs in children and respiratory tract infection is the commonest cause. The study aimed to determine the association of thrombocytosis with severity of lower respiratory tract infection; and the association of degree of thrombocytosis with severity of pneumonia. Materials and methods: This observational study was conducted in the Department of Paediatrics of Fakhruddin Ali Ahmed Medical College & Hospital, Barpeta in Assam. This study was done on 120 children aged between 2 months and 5 years who were admitted with lower respiratory tract infection and classified according to WHO guidelines. Complete general physical examination and systemic examination with special orientation towards respiratory system was done. Complete blood count was performed with automated system sysmex xs800i cell counter. Thrombocytosis was noted and severity of thrombocytosis was classified. Results: Among 120 cases of lower respiratory tract infections, 48 children had thrombocytosis. 13 (48.1%) children with very severe disease, 29 (46.1%) children with severe pneumonia and 6(20%) children with pneumonia had thrombocytosis. Thus it was seen that there was significant association between platelet count and severity of pneumonia (p value=0.018). Two children had severe thrombocytosis (9.01-10.00L/mm3) and both of them had very severe disease. It indicates that degree of thrombocytosis increases as severity of pneumonia increases. Conclusion: There is a significant relationship between thrombocytosis and severity of pneumonia. Also degree of thrombocytosis increases as severity of pneumonia increases. Keywords: thrombocytosis; lower respiratory tract infection; pneumonia; severe pneumonia