Hirsuitism its etiology

 

Abnormal hair Growth(hirsutism)  due to Hyperandrogenism

Hyperandrogenism most often presents as hirsutism, which arises as a result of androgen excess related to abnormalities of function in the ovary or adrenal gland, constitutive increase in expression of androgen effects at the level of the pilosebaceous unit, or a combination of the two.

 

By contrast, virilization is rare and indicates marked elevations in androgen levels. An ovarian or adrenal neoplasm that may be benign or malignant commonly causes virilization.

Hirsutism Hirsutism What is the difference between abnormal hair growth (earlier called hirsutism)  anf Virirlism ?’’

Ans :   Hyperandrogenism most often presents as hirsutism, which usually arises as a result of androgen excess related to abnormalities of function in the ovary or adrenal glands. By contrast, virilization is rare and indicates marked elevation in androgen levels.

 

Androgen effects on hair vary in relation to specific regions of the body surface.

1.Hair that shows no androgen dependence includes lanugo, eyebrows, and eyelashes.

2. The hair of the limbs and portions of the trunk exhibits minimal sensitivity to androgens.

 

3. Pilosebaceous units of the axilla and pubic region are sensitive to low levels of androgens, such that the modest androgenic effects of adult levels of androgens of adrenal origin are sufficient for substantial expression of terminal hair in these areas.

4. Follicles in the distribution associated with male patterns of facial and body hair (midline, facial, inframammary) require higher levels of androgens, as seen with normal testicular function or abnormal ovarian or adrenal androgen production.

 5. Scalp hair is inhibited by gonadal androgens, in varying degrees, as determined by age and genetic determination of follicular responsiveness, resulting in the common frontal-parietal balding seen in some males and in virilized females.

 

Hirsutism results from both increased androgen production and skin sensitivity to androgens.

 

Skin sensitivity depends on the genetically determined local activity of 5a-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT), and the bioactive androgen in hair follicles.