Alopecia areata
This page teaches you diagnosis and
evaluation of people with hair loss meant for medical
professionals
History and Physical Examination
Patient history of alopecia: onset of hair loss, hair loss
pattern (diffuse or focal), rate and timing of hair loss,
other scalp symptoms (itching, burning, tingling)
Personal history: dietary changes, diet, hair-care routine,
hygiene products, medications (prescription medications,
vitamins, over-the-counter [OTC] medications, and herbal
remedies), stress (causes disease by suppressing immune
functions), major illness
Female patient: menstrual and reproductive histories
Any family history of alopecia, patient's concurrent
systemic/chronic illness, physical stress, medication,
environmental exposure, psychiatric disorders, hairstyle,
signs and symptoms of hormonal abnormalities
Physical examination:
Scalp exam for any scars, erythema, scaling, or inflammation
Density and distribution of hair
Hair shaft exam for caliber, length, shape, and fragility
Thyroid palpation to determine thyroid size, nodularity, or
vascularity
Use "pull test" technique for hair loss. Grasp about 60
hairs between the thumb, the index, and the middle fingers.
The hairs are then gently but firmly pulled. A positive test
(2–10 hairs obtained) indicates an active hair shedding.
If a patient demonstrates positive hair-pull tests all over
the scalp, he/she may be warned he/she will most likely lose
all of their hair. Next, provide anticipatory guidance
during the period of extensive hair loss as the cycle
reestablishes and regrowth begins.
Finally, determine if eyebrow, eyelash, axillary, or body
hair is affected. Examine hair density in other areas such
as the face and extremities. A female patient who presents
with thinning scalp hair and demonstrates increased facial,
thigh, chin, or chest hair may have an androgen excess.
Laboratory Studies
Once other causes such as malnutrition, androgenetic,
hereditary conditions (by history, progression, and
presentation), trauma (trichotillomania, traction alopecia),
and drugs (telogen effluvium) have been ruled out, consider
labs for secondary conditions:
For female alopecia with symptoms of hyperandrogenism (such
as menstrual irregularities, infertility, cystic acne,
virilization, or galactorrhea), check total testosterone,
free testosterone, dehydroepiandrosterone sulfate (DHEA-S),
or prolactin levels.
For male and female alopecia without symptoms of
hyperandrogenism, consider measurement of serum thyroid
stimulating hormone concentration to rule out thyroid
disease; venereal disease research laboratory (VDRL)
technique to rule out syphilis; serum ferritin to rule out
anemia; antinuclear antibody test (ANA), RF (rheumatoid
factor) to rule out autoimmune disease; potassium hydroxide
(KOH) examination to rule out tinea capitis; swab a wound
culture to rule out infections; and scalp biopsy as needed
to rule out neoplasm.
Disorders Causing Hair Loss in Adults
Androgenetic alopecia
Male: Hereditary. Dihydrotestosterone compels follicles into
perpetual telogen phase. The earlier oral or topical
treatment is started, the better results one may expect.
Female: Female androgenetic pattern incidence increases with
age. Incidence is approximately 6% in women under 50, but
increases to 38% in women over 70. Female pattern hair loss
typically demonstrates a lower density of hair but maintains
a relatively even distribution, known as "Ludwig"
distribution. Even thinning across the crown is typical,
while the frontal line maintains position.
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