DUPA (Diffuse Unpatterned Alopecia) will not appear in a month. If and when it hits, it will develop over a long period of time (months to years). Chemical damage, on the other hand, will have a short cycle.
We do not understand a great deal about DUPA, but we are aware that the zone of hair around the sides and back of the head may not be permanent in everyone throughout their lifetime. If you go to an old age home and look at many of the men there, about 1/3rd to a half of the men over 80 have a see-through look on the sides and back of the head. When this is evaluated by mapping out the scalp for miniaturization you will see many thin hairs in this ‘donor rim’ that should not be there. This diffuse alopecia may extend throughout the head, even in men who have no balding. These are the people withs of DUPA. I believe that a condition, which the dermatologists have labelled ‘senile alopecia’, is something that hits men in all decades of life and a few men develop this condition when they are in their 20s or 30s. The use of Finasteride (Propecia) has benefits to about half of these men. Many of the poor transplant results that are seen occurs when the patient has DUPA and the surgeon does not check for it. The transplants become thin and the donor area, which was see through prior to the procedure, gets more see through after. I strongly warn every one of those patients I see with DUPA against having hair transplants and consider this condition a contra-indication for hair transplant surgery.
Diffuse Patterned Alopecia (DPA) is an androgenetic alopecia characterized by diffuse thinning in the front, top, and vertex of the scalp in conjunction with a stable permanent zone. Diffuse Patterned Alopecia is usually associated with the persistence of the frontal hairline represented by the hairline position of the
Diffuse Patterned Alopecia differs from the less common Diffuse Unpatterned Alopecia (DUPA) which is also androgenetic, but lacks a stable permanent zone. Diffuse Unpatterned Alopecia( DUPA) patients have a similar progression of balding as the DPA patient except that the progression is often more rapid and will more likely eventuate in a “horseshoe pattern” resembling the Norwood class VII, except that in contrast to the Norwood VII, the DUPA “horseshoe” can look almost “transparent” due to the low density. The differentiation between DPA and DUPA is critically important because DPA patients are often good candidates for an appropriately timed transplant, whereas DUPA patients should almost never be transplanted because they will inevitably have extensive hair loss without a stable zone in which to harvest the hair.
Both Diffuse Patterned and Unpatterned alopecia also occur in women. However, in contrast to men, the DUPA in women is much more common, probably occurring 10 times as frequently as DPA. As in men, the female DUPA patients are not good candidates for a transplant (except in the instance where the donor hair is used solely to soften the frontal edge of a wig). The high incidence of Diffuse Unpatterned Alopecia in women partly explains why so few women have their hair transplanted. It is also important to emphasize that a non-androgenetic differential must be considered in all unpatterned alopecias. This is especially true in women, where a host of medical conditions can produce diffuse unpatterned hair loss including anemia, thyroid disease, connective tissue disease, gynecological conditions, and severe emotional problems.
We find densitometry to be helpful in distinguishing Diffuse Patterned Alopecia from Diffuse Unpatterned Alopecia. A donor density in the range of 1.0 to 1.5 hairs/mm 2 with donor miniaturization in excess of 35% indicates an unstable permanent zone and precludes a diagnosis of DPA. As discussed in the section “Predicting Short- and Long-Term Hair-Loss,” these densitometry readings in a younger patient, even with little clinically apparent hair loss, point toward a high risk of extensive balding. The importance of densitometry is that not only will it help to distinguish between DPA and DUPA, but it can help to predict which patient will not be a good candidate for a transplant even before visible balding has begun. “