IL-6 (pg/ml) according to the different groups of episode at the days of fever 1, 2 and 3. The median is marked by the center horizontal line of the central box. The lower and upper hinges comprise the edges of the central box representing the interquartile range. The Hspread is the absolute value of the differences between the values of the two hinges. The whiskers (⊥) show the range of values which fall within 1.5 Hspreads of the hinges. Values outside the inner fences (+/- 1.5 Hspread) are plotted with empty circles (O).