懷疑femal hirsutism時可抽free testosterone, DHEAS, TSH
Diagnostic procedures in women affected by hirsutism are performed to determine the cause in order to plan the treatment.
In most of the cases, treatment of the underlying cause will cure hirsutism. Though a large proportion of people with hirsutism come to the health care center for cosmetic reasons, sometimes the cause of hirsutism may pose a significant health threat (e.g., a hormone producing tumor).
Basics of the diagnostic procedures in hirsutism:The basic abnormality in hirsutism is increased androgen levels in the blood. The appearance of excess hair in hirsutism is mainly in androgen-dependent areas. This is in contrast with hypertrichosis in which excess hair is present in androgen independent areas also.
Diagnostic procedures in hirsutism include the following:
Physical examination for the confirmation of diagnosis
Hormonal evaluation for confirmation and finding the cause
Imaging studies for finding the cause
Physical examination:This is done for confirmation of diagnosis. It may also give a clue regarding the underlying cause.
The first step is to differentiate hirsutism from hypertrichosis. In hirsutism, the terminal hair is increased in the androgen-dependent areas. In hypertrichosis the vellus hair is increased in androgen independent areas. Terminal hair is coarse, curly and pigmented, whereas vellus hair is fine, soft and non-pigmented.
The next diagnostic step is confirmation of the condition of hirsutism (and not hypertrichosis) and a quantitative assessment. The excess hair should be found in androgen-dependent areas.
For this purpose the Ferrimen and Gallwey scale is used. In this scale 11 androgen-sensitive areas are graded for 0-4 for excess growth of hair.
Grade 0 indicates no terminal hair and grade 4 indicates frankly virile distribution of hair.
These areas include
Upper abdomen and lower abdomen
A score of 8 or more indicates androgen mediated excess growth of hair (hirsutism). A score of 44 indicates the most severe form of hirsutism.
In Asian women, the score in a normal person may vary between 3 in a Thai woman and 11 in a Turkish woman.
Other signs which can be observed include:
Temporal hair recession
Enlargement of the clitoris (>35 mm2 in surface area)
Psychological changes (e.g. heightened libido, aggressiveness)
Palpable abdominal tumors
Acanthosis nigrigans - a skin pigmentation in the arm pits indicating insulin resistance
Hormonal evaluation:Hormonal evaluation as a diagnostic procedure for hirsutism is done for both confirmation and to find the source of origin of excess androgens. Hormonal evaluation is done twice: once to get the baseline value and a second time after the treatment with the hormone dexamethasone. The following hormones and hormone evaluation tests are performed in the diagnosis of hirsutism:
This is the primary androgen and it is elevated in hirsutism. If it is found to be normal, then the free level is estimated which is invariably elevated. In the idiopathic variety both the total and the free levels are normal but the level of 5 Alpha reductase is increased which increases the androgen sensitivity.
Dehydroepiandrosterone sulfate (DHEAS):
This hormone helps in differentiating the origin of excess hormone production. If both testosterone and DHEAS are elevated, then the source is the adrenal glands whereas if only the testosterone levels are elevated, the source is the ovaries.
Dexamethasone suppression test:
The drug dexamethasone is applied for several days and androgen levels are measured.
If DHEAS remains elevated after this test, the most likely cause of the hirsutism is an adrenal tumor.
ACTH stimulation test:
This test helps to differentiate hirsutism due to CAH (congenital adrenal hyperplasia) and the idiopathic variety. In CAH administration of ACTH elevates 17- hydroxyprogesterone levels whereas in the idiopathic variety it has no effect.
Imaging studies:Imaging studies are done mainly to rule out tumors as the source of excess androgens. Imaging techniques used for this are
Computed tomography and Magnetic resonance imaging for localizing adrenal tumors
Ultrasonography for localizing ovarian tumors.
Even though most of the women seek health care intervention for cosmetic reasons, a thorough evaluation is a must to rule out the underlying cause.