posted by John P. Cole, MD on July 7, 2014
There are many different sources for body hair. These include anywhere from the nape of the neck down to the top of the toes. These also represent many different types of hair. The variations are characteristic of the source. The source may include finer hair, straighter hair, curlier hair, coarser hair, shorter hairs, and potentially longer hairs. The wide variety alone make them far different than scalp hair.
Body hair can be separated into two categories: beard hair and the rest of the body. Beard hair is rarely in the telogen (resting) phase whereas other parts of the body may exhibit up to 60% of the hairs in the telogen phase. Beard hairs usually grow as single hair units, but on rare occasions a three hair group may be noted. Only those with a thick beard will have multiple two hair groups. Beard hairs tend to grow at a much more rapid rate and for a longer duration than other forms of body hair. This is why individuals are often able to grow beards that are quite long. Beard hair transplants are far more consistent and will produce a yield typically between 60% and 100%.
Other forms of body hair are usually shorter in length and grow at a slower rate than scalp hair so typically growth is not much longer than 3 to 6 cm in length. The hairs are often curly, but not nearly as curly as most beard hairs. Some forms of body hair grow even shorter such as the hair on your arms, the hair on the tops of the toes and eyebrows. These body hairs are often finer in appearance though sometimes they are just as coarse as head hair. Even when the source of body hair is coarse, the hair will not grow as coarse on top of the head. The hair may produce a cosmetically insignificant result as compared to head hair and beard hair.
In general 1 out of 4 individuals who undergo a non-beard body hair transplant get a cosmetically improved result. Failures include yields of zero %, very fine hair and sparse growth. Even though beard hair transplants produce good cosmetic coverage, some patients do not like the coarse, curly nature of the hair. This contrast in appearance can be quite striking when the scalp hair is fine and straight and beard hair is coarse and curly.
For these reasons, it is often best to perform a test procedure from a hair restoration surgeon prior to undergoing a larger body hair procedure. The test procedure will evaluate the yield and the appearance of the body hair. If the patient and the physician are disappointed in the results, it is probably best to avoid additional procedures.
Ideal candidates for body hair transplants include those whose body hair most closely resembles the other hair in the recipient area. For example, if the recipient hair has coarse and curly hair, the beard may be an excellent source of hair for the thinning area.
Other characteristics that improve candidacy include a lack of sufficient sources of hair on the scalp. Scalp hair is still most preferred because it grows consistently and resembles scalp hair since it is scalp hair. If one has sufficient scalp resources, it is best to use these resources first. Some patients prefer to use body hair over scalp hair. In these circumstances, a trial of body hair might be performed to evaluate the growth and appearance of the grafts.
If one is transplanting specialty areas such as eyebrows or temple points, one might find that some sources of body hair are better than others because the source might appear more like the recipient area. For example in the temple points, one might try arm hair because it is often finer than other sources of body hair. In the eyebrows, body hair grows shorter than scalp hair so one might find that arm hair or leg hair might be optimal. Never the less, scalp hair transplanted to any part of the head is going to produce a more consistent result than grafts from other parts of the body.
When choosing various types of body hair to transplant, it’s best to choose beard hair when consistent results, in terms of yield, are important goals. When trying to match a hair to a specific type of hair on the body, one might sacrifice yield to improve the chance of a better cosmetic match.
There are two factors that tend to improve or decrease the yield. With body hair, hairs in the anagen phase produce a more consistent result. We also know that densities beyond 36 grafts per square centimeter can result in near zero yield with body hair. I recommend that patients have anagen hairs transplanted and that body hair be transplanted at densities below 30 grafts per square centimeter.
We are best able to locate the anagen hair by first performing a wet shave of the recipient area. The hair must be shaved against the grain so that the donor area hair is smooth like hairless skin. The purpose is to help us identify actively growing hairs that will grow longer over the following days. With beard hair, the anagen hairs may be noted the next morning and harvested the next morning. With other forms of body hair, it is best to evaluate the donor area two to three days after shaving because other forms of body hair take longer to grow.
In the absence of a wet shave, one may identify pigmented anagen hairs by a characteristic shadow of pigment below the surface of the skin along the course of growth of the hair follicle.
We have also found anecdotally that Acell injected into the region grafted with body hair can improve the yield significantly.
Body hair transplants are performed just as often as scalp hair transplants. Growth is fairly predictable at three months so patients and their physician will know if desired results are attainable. On a rare instance, a poor yield at 12 months changed to an excellent result between the 12 and 24 month time period.
Some body hair transplants are not equally as successful as scalp or beard hair transplants. Coverage, in general, is easier to achieve with scalp hair so this should be the first line of treatment for hair loss.