Hair Loss In Men
Cause of Hair Loss
Currently in the USA, approximately 50 million men and women are affected by some type of hair loss. One of the most distressing forms of hair loss is Hereditary Androgenic Alopecia, also known as male pattern hair loss (MPHL). The symptoms of this genetically predetermined disorder include physical changes in the hair, including loss of normal vigor and elasticity. Eventually, the hair can become thin and brittle and begin to fall out. In a genetically prone man, the presence of the hormone dihydrotestosterone (DHT) is necessary for this problem to occur.
Some of the less common causes of hair loss that are reversible with treatment, include: thyroid disease, iron deficiency, high fever, surgery or general anesthesia, “crash diets,” and certain medications. There are also certain dermatologic scalp disorders that can result in temporary or permanent hair loss, such as lupus, lichen planopilaris, and alopecia areata.
The tendency for male pattern hair loss is genetically inherited from either side of the family and begins to develop after puberty. Hair on the scalp that is genetically susceptible to androgenic alopecia starts to shrink in the shaft diameter and eventually disappears. The hair on the back and the sides of most men is usually genetically resistant to DHT, which is destined to remain for most of man’s lifetime.
Classification of Hair Loss In Men
In 1941, a classification scale of Male Pattern Hair Loss (MPHL) was introduced by James Hamilton. He classified typical patterns of hair loss into eight major types using a series of drawings. Norwood would refine this system in 1975, offering four additional variations.
Norwood/Hamilton classification scale includes:
1. Type I displaying the normal mature hairline with minimal temporal recession.
2. Type II shows mild temporal recession with thinning along the anterior margin of the forelock.
3. Type III depicts deep frontal recession with few or no remaining hairs, which is the minimal amount of hair loss required for the definition of balding.
4. Type III Vertex shows hair loss confined to the vertex with deep frontal recession.
5. Type IV displays both frontal and temporal recession and frontal thinning together with little hair in the vertex. The bridge between the frontal area and the vertex is still retained.
6. Type V depicts bigger areas of fronto-temporal and vertex alopecia than Type IV and only a narrow and sparse bridge separating both areas.
7. Type VI shows loss of the bridge separating the frontal and vertex areas with lateral and posterior progression of alopecia.
8. Type VII represents the severest form of balding whereby the remaining horseshoe-shaped band of hair in the lower scalp is narrow. The preauricular hairs have receded both posterior and inferiorly. The remaining hair band is frequently of lower density with evidence of some miniaturization. The nape of the neck is sparse and in some cases the inferior occipital border is raised significantly.
Type A variants of the Norwood scale:
Type II A. The entire anterior border of the hair lines lies high on the forehead. The usual mid frontal peninsula of hair is represented by some sparse hair. The area of denudation extends about 2 cm from the mid frontal line.
Type III A. The area of denudation approaches or reaches the mid coronal line.
Type IV A. The area of alopecia extends beyond the mid coronal line. There is some thinning posterior to the actual hairline.
Type V A. This is the most advanced alopecia with this variant. The area of alopecia does not reach the vertex. If it becomes more extensive, it cannot be distinguished from the usual types V and VI.