JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION, Vol 278 No 3, Page 203.
July 16, 1997.

LETTERS

To the Editor - That the article by Dr. Laumann et al[1] documented
differences in the sexual practices of men with regard to circumcision
status is not surprising.  Surgical removal of the prepuce results in the
loss of the majority of fine-touch neuroreceptors found in the penis,[2]
leaving only the exposed nerve glans, which is innervated with free nerve
endings that can only sense deep pressure and pain.[3]

   A hypothesis is needed to explain the findings of Laumann et al in the
light of the known neurohistology.  We suggest that a penis with foreskin
and its full complement of neuroreceptors may make heterosexual coitus more
satisfying, thereby making the man less likely to seek out alternate forms
of stimulation.  The only portion of the prepuce remaining in a man with
surgically altered genitals is the remnant between the corona and the scar.
While there are some fine-touch receptors in this tissue, the most
sensitive portion of the prepuce at the tip is removed in even the most
moderate circumcision.[2]  The remaining prepuce and any remaining portions
of the frenulum can be preferentially stimulated by masturbation and oral
sex, whereas the sensation of deep pressure dominates during heterosexual
coitus.  The imbalance from not having the input from the missing fine
touch receptors may make the experience less satisfying, causing a man with
an incomplete penis to supplement his sexual experiences with other forms
of stimulation.

   To date the effect of circumcision on sexual function has not been
carefully studied.  In rodent studies, removal of the prepuce resulted
in marked changes in the mechanics of copulation,[4] the hormonal response
of the female partner, and aggressive behavior.  In humans, behavioral
alterations have been demonstrated in the pain response of circumcised
infants.[5]  Unfortunately, studies of men circumcised as adults have had
too few subjects or differences in sensation were not well documented.
Testing penile vibratory thresholds has demonstrated that men experience
increasing thresholds with age, while those with premature ejaculation have
low thresholds regardless of age.[5]  Application of this technique could
be used to demonstrate if a sensation differences exists between
circumcised and uncircumcised men.

                                     Robert S. Van Howe, MD
                                     Marshfield Clinic-Lakeland Center
                                     Minocqua, Wis

                                     Christopher J. Cold, MD
                                     Marshfield Clinic
                                     Marshfield, Wis

1. Laumann EO, Masi CM, Zuckerman EW. Circumcision in the United States:
   prevalence, prophylactic effects and sexual practice. JAMA
   1997;277:1052-1057.

2. Taylor JR. Lockwood AP, Taylor AJ. The prepuce: specialized mucosa of
   the penis and its loss to circumcision. Br J Urol 1996;77:291-295.

3. Halata Z, Munger BL. The neuroanatomical basis for the protopathic
   sensibility of the human glans penis. Brain Res. 1986;371:205-230.

4. Luria AR, Szcha RB, Meisel RL. Sexual reflexes in male rats: restoration
   by ejaculation following suppression by penile sheath removal. Physiol
   Behav. 1979;23:272-277.

5. Taddio A, Katz J, Ilersich AL, Koren G. Effect of neonatal circumcision
   on pain response during subsequent routine vaccination. Lancet.
   1997;349:599-603.

Cite as:

Van Howe RS, Cold CJ. Letter. JAMA 1997;278:203.


(Transcribed 17 July 1997)