Abstract

Editorials 2 Strachan DP. Hay fever, hygiene and household size. BMJ 1989;299: factor for later asthma, preventing it by vaccination or 1259­60. passive immunotherapy might reduce the frequency of 3 Prescott SL, Macaubas C, Smallacombe T, Holt BJ, Sly PD, Holt PG. Development of allergen­specific T­cell memory in atopic and normal childhood wheezing in later life, while Illi et al's study children. Lancet 1999;353:196­200. suggests that preventing colds might have the opposite 4 Ball TM, Castro­Rodriguez JA, Griffith KA, Holberg CJ, Martinez FD, effect. Knowing exactly which “dirt” provides the best Wright AL. Siblings, day­care attendance, and the risk of asthma and wheezing during childhood. N Engl J Med 2000;343:538­43. education for the immune system and how to mimic its 5 Shaheen SO, Aaby P, Hall AJ, Barker DJ, Hayes CB, Shiell AW, et al. effects in a cleaner environment seems to be the key to Measles and atopy in Guinea­Bissau. Lancet 1996;347:1792­6. 6 Matricardi PM, Rosmini F, Riondino S, Fortini M, Ferrigno L, Raicetta M, reversing the rise in atopic diseases. et al. Exposure to foodbourne and orofecal microbes versus airbourne viruses in relation to atopy and allergic asthma: epidemiological study. Sebastian L Johnston professor of respiratory medicine