Staging
The diffuse androgenetic alopecias, that we will refer to simply as DA and which consist of Diffuse Patterned Alopecia (DPA) and Diffuse Unpatterned Alopecia (DUPA), can be further divided into various stages of progression with DA 0 representing the pre-balding state. The earliest stage of loss, in these diffuse alopecias, DA 1 , would be characterized clinically by a "slightly thinning" look in the front, top, and vertex, best visualized under strong lights or when the hair is wet. At other times it might not be noticeable. Almost all patients have subjective complaints of less fullness in the affected areas. Preliminary densitometry studies in the thinning area of these patients have revealed miniaturization to be in the range of 20-50%. DA 2 represents the stage when there is obvious thinning evident under normal lighting, but if the hair is styled properly, the degree of hair loss may be acceptable. Miniaturization for DA 2 is on the order of 50-75%. Patients with DA 3 have significant hair loss in the transplanted area, and the coverage it provides is no longer adequate. The frontal hairline, though still recognizable in it's position as the mature hairline, does not have enough density to frame the face. Miniaturization in DA 3 is usually around 75-95%. The DA 4 patient has lost most of his terminal hair in the balding area (miniaturization > 95%), generally has involvement of the crown, and is similar in appearance to the typical Norwood Class VII.
We feel that the early identification of the diffuse alopecia patient is important in order to screen out those who will not be surgical candidates. In addition, because the diffuse alopecias are often associated with a rather rapid progression through the four stages described, the young patient is often not emotionally prepared for this degree of hair loss, especially with DUPA. Long-term planning and careful patient counseling is, therefore, critical before any restoration should be considered. We have not yet determined the exact incidence of the diffuse androgenetic alopecias in the general male population, but they appear to be significantly more common than are the Norwood Class A's.
It is possible that in many instances diffuse, unpatterned alopecia is not a true "androgenetic" alopecia at all but actually represents a similar pathophysiology to what has been termed "senile alopecia," 2 only occurring at a younger age. These authors evaluate the donor area for a miniaturization in every person consulted in our office for hair loss. We believe that some degree of clinically significant diffuse androgenetic alopecia occurs in a substantial number of men as they age. We have observed this in men as young as 17. Regardless of what the actual pathophysiology might prove to be, these authors believe that it is important to make a quantitative assessment of miniaturization , using densitometry, when evaluating each patient so that the physician can more accurately determine the total available supply of stable donor hair.
Treatment
We feel that the decision if and when to begin surgical treatment of the patient with Diffuse Patterned Alopecia is problematic for a number of reasons: 1) we find the patients with DPA tend to be very young, 2) the hair loss tends to progress rapidly, 3) the position of the existing frontal hairline is often unrealistically low, 4) there is a high risk of accelerated hair loss from the surgery, and 5) the patient may become extensively bald.
The physician should encourage the patient presenting with diffuse alopecia to wait as long as possible before beginning the first procedure. Delaying surgery will have a number of advantages. First, the diagnosis of Diffuse Patterned Alopecia can be more secure, so that the risk of operating on a patient who might eventuate into DUPA can be minimized. Second, waiting will enable the patient to move beyond his early "panic" phase and think clearly about whether he really wants to have a transplant which may possibly eliminate his option of wearing his hair very short if he were to become extensively bald (because of the inability to hide the donor scar). Third, because in DPA, even in the early stages, the area to be transplanted is essentially a "sea of miniaturization," the risk of acceleration of hair loss from the surgery is much higher than in the other Norwood classes. Last, the lack of significant hairline recession makes it more difficult for the young patient to visualize and accept a hairline in a more conservative, but appropriate location.
The DPA 2 patient can usually achieve a satisfactory appearance with a little more attention to styling his hair and should, therefore, not be transplanted given the risks outlined above. Patients with DPA 3 are appropriate candidates as long as the transplant is aggressive with regard to the number of implants, and the planning is conservative with regard to its design. Specifically, this means that the transplant should include the front, top, and vertex in the first session, but not extend into the crown, and appropriate bitemporal recession should be built into the design, even if it is behind the patient's existing hairline. The number of implants used should essentially be the same as if the patient was totally bald in the transplanted area, since this hair will most likely be lost in the near future. If it is anticipated that the number of implants planned in the first session will not produce a cosmetic impact at least as great as the existing hair, then the procedure should be postponed, or the risk of the procedure will outweigh the possible benefits. In addition, the implants should cover the entire area described above in one continuous unit. Although the distribution and weighting will vary depending upon the aesthetics of the transplant, the surgery should not be performed in sections or in multiple stages. As in the proper planning of all transplants, the patient must have a scalp laxity and donor density commensurate with the potential area that needs to be transplanted and must have good hair characteristics for the procedure to be worthwhile. The risk of acceleration of hair loss due to the surgery and the probability of extensive baldness must, of course, be emphasized. The DPA 4 is the easiest to manage, since the risk of effluvium is gone and patient expectations are usually more realistic. These patients should be transplanted in a manner similar to the Norwood Class 6 or 7.
