Healthy skin is covered with a thin layer of protective fluid called the acid mantle. The acid mantle is maintained by secretions from certain types of glands in the skin (Figure 1).
Skin pH over 6.5, less acidic, causes two problems. First,
the normal protective barrier breaks down and skin cells are
pulled away from one another. The skin becomes irritated and
susceptible to further damage by environmental irritants.
Second, there is an increased risk of infection because the
growth of
bacteria and yeasts
is no longer controlled by the normal acidity on the skin.2
Causes of Perianal and Vaginal Itching
Irritation and itching (pruritus)
in the perianal and external vaginal
areas are caused by an imbalance in skin pH. This imbalance
usually is the result of gastrointestinal
abnormalities that cause diarrhea, constipation, anal
fissures or hemorrhoids.
In addition, life style choices and normal physical changes
due to pregnancy and aging can affect the perianal
and external
vaginal flora.
Illness
Perianal
and vaginal
irritation and itching often is the result of acute infections
or chronic conditions that disturb the balance of intestinal
flora and lead to diarrhea or constipation. Chronic diseases
of the intestinal tract such as Crohn's
disease and ulcerative
colitis commonly are associated with diarrhea. Patients
with irritable
bowel syndrome experience cycles of diarrhea and constipation.
Constipation can produce painful hemorrhoids
as well as anal fissures.3,
4
Medical Treatment
In the healthy acid mantle of the skin yeasts
and bacteria are in perfect balance. Antibiotics
kill not only harmful bacteria but also beneficial bacteria
of the vagina. Therefore, antibiotic treatment can allow the
uncontrolled growth of yeast
and result in vaginal
yeast
infections. In addition, antibiotics can cause diarrhea or
constipation in some patients. Other medical treatments such
as radiation therapy and digestive tract surgery may be associated
with diarrhea.4, 5
Life Style Choices
Food choices and hygiene routines can impact
skin health in the perianal
and vaginal
areas. Certain foods are known to produce diarrhea. These
include caffeinated and alcoholic beverages as well as acidic
and spicy foods.6
Strongly alkaline
soaps can raise the skin's pH to unhealthy levels. The use
of scented toilet paper, soaps, or ointments also can cause
rectal pruritus
(also known as
pruritus ani).6
Natural Body Changes
The hormonal adjustments throughout pregnancy may lead to constipation and hemorrhoids. Progesterone decreases intestinal motility, increases the absorption of fluid from the intestinal tract and leaves women with harder stools. At the same time the additional weight of the growing baby impedes blood flow away from the anus. The blood pools in the veins around the anus and creates hemorrhoids.7
Hormonal changes affected by birth control
pills or patches, pregnancy or menopause
predispose women to vaginal
yeast infections. Pregnancy, for example, increases vaginal
pH and promotes the storage of sugar in vaginal cell walls.
Yeast thrives in this environment. In non-pregnant women,
monthly menstrual flow creates the moist, warm conditions
that invite the growth of
yeast.5, 8
Menopause
changes cervical mucus and makes women vulnerable to dryness,
external vaginal itch and yeast
infections. Pastore et al.
found that 27.0% of post-menopausal women aged 50 to 79 years
old reported urogenital dryness and 18.6% said that they had
irritation or itching in the
perianal/external vaginal area. This is aggravated by
the natural decrease in blood flow and gland secretion in
aging skin which make it more susceptible to damage and slower
to heal. Many older women also have to manage incontinence
associated with a constant flow of irritants to the
perianal and external vaginal areas. 9,
10
Hemorrhoids
Hemorrhoids
mostly affect adults 45 to 65 years old. An estimated 10 million
Americans suffer from hemorrhoids
and approximately 75% of adults experience
hemorrhoids at least once in their lives.11
Excessive pressure on the blood vessels in the rectal area
causes hemorrhoids.
As described above, common causes for this change in pressure
are excessive straining during bowel movements, constipation,
obesity, pregnancy and childbirth, as well as diarrhea.
Hemorrhoids
are usually associated with lump-like bulges at the anus,
itching, soreness and pain in the anal area. Bloody stools
or hemorrhoids
that do not respond to at-home treatment may be due to more
serious medical conditions and therefore should be examined
by a physician.12
However, most hemorrhoidal symptoms can be relieved safely
with sitz baths, icing of the affected region, hemorrhoid
or anti-itch creams and careful cleansing of the anal area.

|