All patients with necrotising fasciitis seen at this hospital over 10 years were reviewed. Six cases were found in which non-steroidal antiinflammatory drugs were suspected of having contributed to the infection; these cases are reported below. Patients, methods, and resultsThe records of all 31 patients seen at this hospital during '-3 No underlying disease was present in our patients, but all had been given non-steroidal anti-inflammatory drugs. The sequence of events suggested that these compounds affected the development or extension of the disease in our patients as no other drugs were given. Activation of latent infections in debilitated patients treated with non-steroidal anti-inflammatory drugs was suspected by Solomon.4 In vitro studies support this hypothesis by suggesting that functions mediated by granulocytes, which are critical in the early stages of host defence against infection, may be impaired by non-steroidal anti-inflammatory drugs. In vitro chemotaxis, phagocytosis, and bactericidal activity of granulocytes are reduced by these drugs. Solberg et al observed reduced in vitro killing of Staphylococcus aureus and streptococcus group B by granulocytes incubated with phenylbutazone.5 Whether these effects occur in vivo in patients given non-steroidal anti-inflammatory drugs remains to be determined.Our observations suggest that non-steroidal anti-inflammatory drugs should be used cautiously when infection is suspected in a patient with an apparently benign "non-specific" inflammatory lesion of the skin.We thank Dr Jonathan L Meakins (McGill University, Montreal) for his advice.