What is Hypertrichosis?

Hypertrichosis is a medical condition characterized by an excessive growth of hair in the human body. This excessive hair growth occurs in areas where there is no hair in the human body.

Hair Follicle

Hair Follicle

Hypertrichosis is commonly known as Ambras syndrome or werewolf syndrome. It can affect both men and women of any race or age. Luckily, this medical condition is rare affecting only a few people each year in the United States.

Hypertrichosis includes dense hair growing in one area of the human body, or it can be unusually long. There are two types of hypertrichosis known:

  • Localized hypertrichosis – characterized by an excessive growth of the hair in one specific part of the human body, and
  • Generalized hypertrichosis – characterized by an excessive growth of the hair affecting the entire human body. In general, excessive hair growth occurs in the upper body part and facial area.

The first hypertrichosis case was reported back in the 17th century on the Canary Islands by Altrovandus. (1)

What causes Hypertrichosis?

The real cause of hypertrichosis is not known. Hypertrichosis can be either inherited or acquired.

Congenital hypertrichosis

Congenital hypertrichosis

Congenital hypertrichosis is a very rare medical condition which is inherited and runs in the families. Researchers believe that a genetic disorder due to gene mutation results in hypertrichosis. According to the University of Southern California, this gene is known as the SOX3 gene. Less than 100 cases with hypertrichosis have been verified until today. On the other hand, acquired hypertrichosis is a medical condition which occurs after birth. Hypertrichosis cases have been reported also after being diagnosed with cancer. (2)

Generalized and acquired hypertrichosis can be associated with:

Generalized hypertrichosis

Generalized hypertrichosis

  • Malignancy,
  • Malnutrition,
  • Porphyria cutanea tarda,
  • Certain medications such as androgenic steroids, cyclosporin, etc.

Localized and acquired hypertrichosis can be associated with:

  • Lichen simplex,
  • Trichomegaly,
  • Repeated application of topical medications such as iodine, steroids, etc.,
  • Increased vascularity,
  • Temporary application of plaster cast, etc.

Localized hypertrichosis

Localized hypertrichosis

Signs & symptoms

A characteristic symptom of hypertrichosis is the excessive hair growth which can affect just one are of the human body or it can be generalized affecting the entire human body.

Congenital hypertrichosis is noticed since a person is born, while acquired hypertrichosis occurs later in life. In acquired hypertrichosis, the hair growth is localized or generalized, while the terminal hair is pigmented or unpigmented. Sometimes, even teeth defects and gum diseases are noticed.

Once diagnosed with hypertrichosis three different hair types can be noticed:

  • Terminal hair – dark, long and thick hair.
  • Vellus – light colored, short and fine hair which is barely noticed and which covers the entire human body except certain areas of the body such as hand palms, feet soles, lips, back of the eyes, external genital areas, navel and scar tissue. How dense vellus will be is different from one person to the other.
  • Lanugo – non pigmented, fine and soft hair, usually noticed in newborns. Newborns are covered in lanugo, which usually goes away on its own within the first few days or weeks after birth.


Hypertrichosis is diagnosed only by a clinical examination of the patient. Excessive hair growth is noticed in localized or generalized areas of the human body.

Hirsutism is often misdiagnosed as hypertrichosis. Even though hirsutism can be both, inherited or acquired just as hypertrichosis, it is diagnosed only in children and women. Hirsutism is characterized by an excessive hair growth in the human body due to excessive androgen sensitivity. In women and children, hair is localized in areas which are characteristic for males such as in the upper chest, back or facial area. Other signs and symptoms of hirsutism include irregular menstrual periods, acne, a masculine body shape, deepening of the voice, etc.


Hypertrichosis is not a life – threatening condition even though it can be quite disturbing especially when generalized or when affecting the upper body part and the facial area. It’s up to you if you want to treat it or leave it just as it is. However, most of the patients diagnosed with hypertrichosis decide to treat it as it can attract attention from other people.

Shaving the hair or using depilatories will only prevent a temporary solution as the hair will grow back. Bleaching products are also available which help make the hair less noticeable.

A permanent removal of excessive hair which grows in the human body is the only solution. Permanent hair removal options available today include laser surgery and other permanent hair removal treatments. Choosing these treatment methods can be quite difficult as they require time and are expensive. Hair removal laser surgery destroys the hair follicle, meaning that the hair will no longer grow back on the treated areas. It will also slow down any hair growth. However, multiple laser treatments are required before the desired results are achieved. Periodic maintenance treatments every now and then might be needed as well.

Laser Hair Removal

Laser Hair Removal Treatment

Just like any other treatment, laser hair removal treatment can has its own side effects and possible complications. Common side effects of laser hair removal include skin irritation and depigmentation or hyperpigmentation of the skin, while rarely side effects of laser hair removal include blisters, sores, crusting or scarring of the skin.


  1. Hypertrichosis Available at: http://www.en.wikipedia.org/wiki/Hypertrichosis
  2. Hypertrichosis Available at: http://www.emedicalhub.com/hypertrichosis/
  3. Hypertrichosis Available at: http://www.healthtool.com/hypertrichosis/
  4. Hypertrichosis & Hirsutism Available at: http://www.hairscientists.org/hair-loss-conditions/hypertrichosis-hirsutism
  5. Hypertrichosis Available at: http://www.dermnetz.org/topics/hypertrichosis/

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