Classification of Hamilton for Types of Male Pattern Baldness

 

Ebling and Rook modified the Hamilton types, with their types II to V corresponding to Hamilton types V to VIII.

 

Types with Minimal Hair Loss (Not Considered as Bald)

 

Type I:

(1) thinning or loss of hair without the bilateral recessions along the hairline in the frontoparietal regions

(2) variant A: entire anterior border of the hairline lies high on the forehead

 

Type II:

(1) bilateral frontoparietal recessions, usually symmetrical and triangular in shape

(2) the recessions do not extend into the area 3 cm anterior to the coronal plane connecting the 2 external auditory meates

(3) the anterior border of the hairline may be receded but the extent is less than the loss in the frontoparietal regions

 

Type III:

(1) borderline cases

(2) cases where classification is difficult due to scarring or asymmetry

(3) unusual cases of sparseness and thinning

 

Types Associated with Mild Baldness

 

Type IV:

(1) bilateral frontotemporal recessions extending further back than type II, less than 3 cm from the coronal line connecting the external auditory meatuses

(2) variant A: hair sparse or lacking as a broad band along the entire anterior border of the hair line

(3) variant "old": an elderly person with loss of some hair over the crown but without extensive hair loss in the frontotemporal or frontal regions

 

Type V:

(1) sparseness or absence of hair over the crown

(2) frontal recession of the hairline

(3) bilateral frontoparietal recessions approaching close to the coronal line connecting the external auditory meatuses

(4) bands of intact hair separating the denuded crown from the other areas of hair loss

 

Types Associated with Moderate to Severe Baldness

 

Type VI:

(1) horseshoe area of alopecia

(2) sparseness or absence of hair over the crown is more extensive than type V

(3) the tonsural region of alopecia over the crown is separated from the frontal and frontoparietal areas of hair loss by a laterally directed (coronal) band of hair which may be incomplete

(4) a small frontal island of hair may be present in the midline

(5) variant A: the peninsular or island of mid-frontal hair is sparse or lost

 

Type VII:

(1) horseshoe area of alopecia, more extensive than Type VI, with confluence of the hair loss in the frontal, frontoparietal and crown regions

(2) no band or island of mid-frontal hair

(3) there is still at least 1 clump of at least 100 terminal (coarse) hairs in one of the 3 regions

 

Type VIII:

(1) horseshoe area of alopecia is more extensive than in type VII and extends laterally and posteriorly

(2) terminal (coarse) hairs within the area of alopecia occur as isolated structures without clumps of >= 100 hairs