Pruritus ani, piperazine, and thrombocytopenia
Cork, M.J.; Cooke, N.J.; Mellor, E.
BMJ 301(6765): 1398
1990
ISSN/ISBN: 0959-8138 PMID: 2271898 Document Number: 351931
A 61-year-old man from the UK developed perianal pruritus, noticed worms in his faeces and assumed an Enterobius vermicularis infection, similar to an infection he had been treated for, with piperazine, 15 years previously. Assuming this was the same infection, he treated himself to 2 over-the-counter preparations, piperazine hydrate, and 3 weeks later, piperazine phosphate. He took two 7-day courses of piperazine hydrate (2.25 g daily) starting on 19 September and 4 October 1989. On 28 October and 25 November he took 4 g of piperazine phosphate. Five days later he developed epistaxis and haemoptysis that persisted for one month. On examination is chest was clear and no worms were visible perianally or by the sellotape test. His chest radiograph and haemoglobin concentration were normal. His platelet count was 26x109/litre after the haemoptysis had resolved. He was instructed to avoid piperazine and his platelet count rose over 3 weeks to 170x109/litre. It is suggested that severe thrombocytopenia in the patient after exposure to piperazine was probably the result of sensitization 15 years previously.