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The Causes of Recurrent
Patchy Hair Loss - Alopecia Areata.
The Causes
of Recurrent Patchy Hair Loss - Alopecia Areata.
What is Alopecia Areata?
Alopecia areata is a localized, patchy, non
scarring type of hair loss, characterized by the presence of one or more round
or oval hairless patches. The affected skin appears normal and smooth, unlike
the fungal infections, where there is crusting of the skin and uneven breaking
of hairs.
On the periphery of the patches, a few short
hairs, which taper and loss pigment as they approach the skin, may be seen.
These are called "exclamation mark" hairs due to their resemblance to
the mark.
Alopecia areata usually affects the scalp. Other
hair bearing areas, especially the beard are also affected. Any age can be
affected in alopecia areata; though the common age group is 15-30. The
youngest alopecia areata patient I have seen was a 2 year old girl.
What are the Causes of patchy hair
loss (Alopecia Areata)?
1. Autoimmune theory: Alopecia areata is
thought to be an autoimmune disease where the body produces antibodies ('auto'antibodies)
against the hair germinal cells and cause their destruction in localized
areas. The localization of lesions also point towards a neural pathway
involvement. In patients with graying hairs, it is common to see that only the
black hairs fall off in the patches. Sparing of the grey hairs in alopecia
areata indicates that normal nerve supply and melanin pigment is necessary for
the alopecia areata to occur.
2. Direct pressure:
Many patients get patchy hair loss(alopecia areata) following direct pressure
on hair bearing areas, e.g., from a tight fitting helmet, pressing the head
against bed rails for prolonged duration while watching TV etc.
3. Mobile phones and
patchy hair loss(alopecia areata): Another complication of the
modern device! Before the hands free sets became common, a number of patients,
especially those using cheaper brands of cell phones, presented with alopecia
areata on their beards. Possibly the radio waves emitted by the mobile phone
damaged the hair follicles and triggered an autoimmune inflammatory reaction
in the area. Most of them also had dull aching pains in their ear on the same
side.
4. Caries tooth:
This is a very important factor usually ignored by patients and their doctors
alike. In the Middle East where I practice, there is a very high incidence of
alopecia areata. In my practice, I come across almost 6-7% alopecia cases
among the total skin diseases. In addition to stress, one common factor that I
noticed was the presence of caries tooth in almost all cases with recurrent
patchy hair loss, especially on the beard. Research showed that alopecia
areata of dental origin has indeed been mentioned in scientific journals.
Personally I make a habit of referring all my
alopecia areata patients who come with recurring patchy loss of hair,
especially resistant to treatment, to a dental surgeon. Most such patients
stop getting recurrences after their teeth infection is taken care of.
Possible explanation of the relationship between
caries tooth and alopecia areata: Tooth germinal cells and hair germinal cells
have embryological and histological similarities. Hence, the antibodies
forming against damaged tooth germinal cells and the bacteria attacking them
must be affecting the hair follicles as well.
This is only a hypothesis and
need to be studied further. The involvement of nail (nail pits) in alopecia areata supports this hypothesis, as nail is another integument of the skin
that is similar to the tooth and hair!
5. Stress:
Most patients who come with recurrent episodes of alopecia areata also report
a preceding period of intense stress in their life. How the stress causes hair
loss only in localized patches, is however, not known. Hypothetically the
nerve supply and altered immune responses in stress may be playing a role in
the causation of alopecia areata.
Corroborative studies where cure has been
affected following implementation of stress management techniques in non
responsive patients point to a positive role of stress in the causation of
alopecia areata.
Part 2:
Tips on Dealing with Alopecia Areata.
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The Causes of
Recurrent Patchy Hair Loss (Alopecia Areata).
