To the Editor: In the recent article by Spilsbury and her colleagues on circumcision for phimosis, a key part of their argument hinged on probable rates of phimosis among boys.1 I take no stance for or against circumcision, but I have published on evolutionary aspects of the human foreskin and the origins of circumcision,2 for which I surveyed the literature on the occurrence of phimosis.

Spilsbury et al quote a reported rate of phimosis among boys aged under 15 years of 0.6%.3 However, this refers to "pathological phimosis, a condition unambiguously characterised by secondary cicatrisation of the orifice, usually due to balanitis xerotica obliterans",4 and not to phimosis in the usual sense: "the narrowing of the pre-putial orifice, leading to an inability to retract the foreskin, or prepuce, over the glans penis".1 As Spilsbury et al treat balanitis xerotica obliterans separately from phimosis in their classification of reasons for circumcision,1 this is not a valid citation.

The authors also quote Øster's study of a large cohort of Danish boys5 as giving a rate of phimosis of 1.5% at age 17, but, in fact, a further 2% were reported as having "tight" foreskins, and this was at the conclusion of an 8-year study during which retraction of each boy's prepuce was attempted annually, and the boys were given instruction on foreskin hygiene. It was therefore a report on a project of conservative foreskin management, and not a survey of a population. At the start of the trial, at age 8 years, 8% of the boys had phimosis. Spilsbury et al state (without references) that preputial adhesions resolve in boyhood without requiring surgical intervention,1 yet Øster found that 3% still suffered from adhesions at age 16–17 years.5

The authors cite Gairdner's classic study6 as the authority that phimosis should not be diagnosed in infants, yet, curiously, it is not mentioned that he reported a 20% incidence of phimosis in boys aged 5–13 years.

Thus, even the references cited give a very different impression of the incidence of phimosis among boys than would appear from the way they are quoted. Looking at other studies, an investigation of over 1000 adult soldiers in the British Army found that 14% of the uncircumcised men suffered from phimosis,7 and a German study of 3000 adults found that 9.2% of those who were not circumcised also suffered from phimosis.8 Studies in Asia have found much higher rates of phimosis — in both Japan9 and Bali,10 rates of up to 50% have been reported. The difference is attributed to cultural rather than anatomical factors.10

It is clear that phimosis in boys and adult men is very much more prevalent than Spilsbury et al claim. This inaccur-acy is particularly disturbing when a publication is associated with an official survey of the quality of surgical care. Given that the topic of circumcision sometimes arouses strong feelings, it is particularly important to be accurate and impartial when studying it.