Q: It is my understanding that as a person loses his or her hair, the skin of the scalp undergoes a number of changes, namely there is a loss of fat, an increase in cellular atrophy, and of course the dreaded perifollicular fibrosis (now that’s a mouthful). It seems to me that these changes, in particular the fibrotic scarring, are the main obstacles in the way of regrowth, and the reason Propecia does not work for extensively bald men. What can be done about this demon we call fibrosis? Can it be slowed, stopped, prevented, reversed? If we could somehow counteract collagen formation, wouldn’t our baldness problems be solved for good? If a bald scalp is atrophic, how does it have the capacity to hold a whole new head of transplanted hair? Is there a limitation to the number of hairs we can transplant (outside of donor limitations)? — R.L., Rivington, C.T.

A: The findings that you are describing are well documented; however, it is not clear if these changes are the cause of the hair loss or are the result of having lost one’s hair. Most likely, the DHT causes the hair follicles to miniaturize and eventually disappear. This, in turn, causes the scalp to thin and lose its abundant blood supply (whose purpose is to nourish the follicles). The changes in the scalp are also affected by normal aging, which causes alterations in connective tissue including the breakdown of collagen and other components of the skin. The changes seen with aging are greatly accelerated by chronic sun exposure.

Fortunately, even with long-standing baldness there is still enough blood supply to support a hair transplant, although there are some limitations. One should perform a hair transplant with a lower density of grafts when patients have thin, bald fibrotic scalps since the blood supply is diminished.

The most important factor, however, is photo change. The sun dramatically alters the connective tissue making the grafts less secure in their sites and alters the vasculature, (blood vessels) decreasing tissue perfusion (blood flow to the tissues). When there is bald atrophic, sun damaged scalp, I generally perform two hair transplant sessions of lower density (in place of one) spaced at least a year apart to give time for the scalp to heal and blood flow to increase in the area.

I often have the patient treated with topical 5-flurouracil before the surgery to improve the quality of the skin and to treat or prevent pre-cancerous growths from the sun.