All the above data suggest that the main mechanism for the possible role of sex hormones in HS lies in end-organ sensitivity rather than in the plasma levels. Women can develop HS while taking oral contraceptives especially when an-drogenic progestins are used, and this also suggests, as in acne, a possible androgen dependence of the disease . In acne, not only sebocytes but also other epithelial cells are involved in the "skin hyperandrogenism" that is responsible for the formation of the comedo. Keratinocytes from the acroinfundibulum express the key enzymes involved in the in situ metabolism of androgens (in situ synthesis of the weaker androgens, their transformation into testosterone and its reduction into DHT) . Investigation for the activity of these enzymes in the epithelial cells that are presumed to be involved in the first stage, i.e. follicular occlusion, of HS remains to be conducted.
However, androgen metabolism has been investigated in normal human apocrine glands and in those isolated from age-matched patients with HS . No increased activity of 3|3-hy-droxysteroid dehydrogenase, A4-5 isomerase, or 17 p-hydroxysteroid dehydrogenase was found and 5a-reductase activity was similar. These results suggest that HS cannot be attributed to exaggerated activities of androgen-interconvert-ing enzymes within apocrine gland cells.
These data should not be interpreted as reflecting a lack of apocrine sensitivity to andro-gens, since they relate to the quantity of active metabolite (DHT) and not to the androgen response at the receptor level. It cannot be excluded that there is increased sensitivity of cellular AR, due to genetic polymorphism of the receptor, that might account for the as yet hypotheti-
cal skin hyperandrogenism in women with HS. On the other hand, a genetic polymorphism in enzyme activities at the epithelial cell level remains to be demonstrated. Finally, in the absence of precise investigations, based upon biological markers (testosterone, A4A, 17-OHP, SHBG levels, free testosterone index) and ovarian echography [1, 7], the possibility that some women with HS suffer from PCOS or NCAH cannot be excluded.
Was this article helpful?