Incidentally detected thrombocytopaenia in adults

With the advent of automated counters, low platelet counts are a common incidental finding. The list of possible aetiologies is long and exhaustive (Figure 1, available online only). Platelet abnormalities range from having no clinical relevance to being the only initial manifestation of a serious underlying disorder.

This article provides general practitioners with an approach to differentiating the benign from the life-threatening causes of thrombocytopenia using routine pathology testing in adults.

There are no specific laboratory tests that can conclusively identify the mechanism of thrombocytopenia - a thorough history, clinical examination, and blood results remain the initial means of diagnosis.