I have a red itchy lump that has just appeared on my scar i had surgery on my arm under a year ago. is this normal and what do i do ?

Stitch abscess: Sometimes around the remaining stitch material our body develops inflammatory reaction which can result in stitch abscess which can appear delayedly and also stitch granuloma which is a lump but not containing pus , made of aggregation of inflammatory cells and supporting fibres-elastin and collagen,our natural body fibres. Show to your PCP/Surgeon . In some cases it need to be explored .