Reply

D. Symmons

University of Manchester, Oxford Road, Manchester, UK

SIR, We would like to thank Dr Zauli and her colleagues for their interest in our paper in which we reported a fall in the prevalence of rheumatoid arthritis (RA) in the UK [1] since the 1950s. This fall was observed in women but not in men. We suggested that the observed changes in prevalence might be explained by a protective effect of the oral contraceptive pill or another factor related to taking the pill. They suggest an interesting alternative hypothesis, namely that the presence of atopy confers some protection against RA and that the observed changes in the prevalence of RA may be attributed to an increase in the prevalence of atopy. The two hypotheses are not, of course, mutually exclusive and both might play a role.

For the ‘atopy theory’ to be the predominant explanation there would be a need for the prevalence of atopy to have increased in women but fallen in men. Zauli et al. report a low prevalence of RA in a group of 1937 adults attending an allergy clinic. In order to interpret this low prevalence, we need to know the expected number of cases in an age- and sex-matched sample of the general Italian population. The prevalence of RA in Italy is probably lower than in the UK [2]. There would also be a need to consider whether the attenders at the allergy clinic are representative of all Italian atopic subjects or whether there may be some referral bias.

Notes

E-mail: deborah.symmons{at}man.ac.uk Back

References

  1. Symmons D, Turner G, Webb R et al. The prevalence of rheumatoid arthritis in the United Kingdom. Rheumatology 2002;41:793–800.[Abstract/Free Full Text]
  2. Cimmino MA, Parisi M, Moggiana G et al. The prevalence of rheumatoid arthritis in Italy— The Chiavari Study. Ann Rheum Dis 1998;57:315–8.[Abstract/Free Full Text]
Accepted 16 September 2002





This Article
Full Text (PDF)
Alert me when this article is cited
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Disclaimer
Request Permissions
Google Scholar
Articles by Symmons, D.
PubMed
PubMed Citation
Articles by Symmons, D.
Related Collections
Rheumatoid Arthritis