Hair Care - DermaAmin

Hair physiology 17
a club-shaped proximal end. If the body has prematurely placed many hair follicles into
the resting phase, the condition is known as telogen effluvium.
2. What is the magnitude of the hair loss?
Hair loss can be easily distinguished from hair breakage by performing 10 hair pulls over
various areas of the scalp. The hair pull is performed by grasping the hair shaft close to
the scalp with the fingers and firmly pulling over the length of the shaft. Removed hairs
are examined for the presence and formation of the bulb. If more than six hairs are
removed per pull, excessive hair loss is present. This procedure also provides an
opportunity to determine if any scalp disease is present that might be contributing to the
hair loss.
However, hair pulls in the office can be misleading, especially if the patient has
shampooed prior to being examined and has removed the loose or broken hairs.
Questioning of the patient as to the magnitude of hair loss may also be misleading, since
most are not aware that a normal individual may lose approximately 100 hairs per day. If
grooming of the hair is infrequent, shampooing may yield up to 200 or more lost hairs.
3. Is hair breakage occurring?
Hair breakage occurs as a result of weakness in the structure of the hair shaft. Information
about the magnitude of hair breakage can best be obtained by having the patient collect
all hair lost for 4 consecutive days and place each day’s loss in a separate plastic bag,
noting the days when shampooing was performed. The hair should be brushed or combed
over the sink and the hair collected from the sink and also from the brush or comb. Hairs
should also be removed from the drain following shampooing. The dermatologist can
examine each day’s loss, noting both amount and presence or absence of the hair bulb to
determine in which growth phase the hairs were shed and also if hair breakage has
occurred.
Hair breakage can result from improper grooming practices, the topic of discussion in
Chapter 7. However, abnormally formed hair shafts, found sporadically or in association
with genodermatoses (trichoschisis, trichorrhexis invaginata, pili torti, monilethrix, and
trichorrhexis nodosa), can also result in decreased hair shaft strength and subsequent
breakage. Examination of several plucked hairs under the microscope is necessary to
insure normal hair structure. This topic is discussed more fully in the next section.
4. Is there a treatable medical cause?
If more than 100–125 hairs are lost per day, and it has been determined that normally
formed hairs are being shed diffusely from a nonscarred scalp with an intact bulb, anagen
effluvium, telogen effluvium, and other medically induced causes must be considered.
Anagen effluvium is generally due to internally administered medications, such as
chemotherapy agents, that act as cell poisons and disrupt the growing hair follicle.
Telogen effluvium, on the other hand, is due to an increased number of hair follicles
prematurely exiting the anagen phase or hair cycle synchronization. 42 Premature anagen
exit can be due to medications, such as coumarin or heparin, while hair cycle
synchronization occurs during pregnancy and with oral contraceptive use.
There are several medical causes of hair loss, which require treatment prior to hair
regrowth. These are summarized in Box 1.2. Most of these considerations can be