The palms, soles, and mucous membranes are not affected. Terminal hypertrichosis
Congenital terminal hypertrichosis is characterized by the presence of fully pigmented terminal hair that covers the entire body. This condition is usually accompanied by gingival hyperplasia. This form is most responsible for the term "werewolf syndrome" because of the thick, dark hair that appears. People with this condition are sometimes performers at circuses because of their unusual appearance. Circumscribed hypertrichosis
Congenital circumscribed hypertrichosis is associated with the presence of thick vellus hair on the upper extremities. Circumscribed signifies this type of hypertrichosis is restricted to certain parts of the body, in this case, the extensor surfaces of the upper extremities. Hairy elbow syndrome, a type of congenital circumscribed hypertrichosis, shows excessive growth on and around the elbows. This type of hypertrichosis is present at birth, becomes more prominent during aging, and regresses at puberty. Localized hypertrichosis
Congenital localized hypertrichosis is a localized increase in hair density and length. Nevoid hypertrichosis
Nevoid hypertrichosis may be present at birth or appear later in life. It features an isolated area of excessive terminal hair and is usually not related to any other diseases. Acquired
Acquired hypertrichosis appears after birth. The multiple causes include the side effects of drugs, associations with cancer, and possible links with eating disorders. Acquired forms can usually be reduced with various treatments. Hypertrichosis lanuginosa
Acquired hypertrichosis lanuginosa is characterized by rapid growth of lanugo hair, particularly on the face. Hair also appears on the trunk and armpits, while palms and soles are unaffected.
There are three stages of the hair cycle: the anagen phase (hair growth), the catagen phase (hair follicle death), and the telogen phase (hair shedding). If the anagen phase increases beyond what is normal, that region of the body will experience excessive hair growth. Diagnosis
Hypertrichosis is diagnosed clinically by the occurrence of hair in excess of what is expected for age, sex, and ethnicity in areas that are not androgen-sensitive. The excess can be in the form of excessive length or density and may consist of any hair type (lanugo, vellus, or terminal). Management
There is no cure for any congenital forms of hypertrichosis. The treatment for acquired hypertrichosis is based on attempting to address the underlying cause. Acquired forms of hypertrichosis have a variety of sources, and are usually treated by removing the factor causing hypertrichosis, e.g. a medication with undesired side-effects. All hypertrichosis, congenital or acquired, can be reduced through hair removal. Hair removal treatments are categorized into two principal subdivisions: temporary removal and permanent removal. Treatment may have adverse effects by causing scarring, dermatitis, or hypersensitivity.Temporary hair removal may last from several hours to several weeks, depending on the method used. These procedures are purely cosmetic. Depilation methods, such as trimming, shaving, and depilatories, remove hair to the level of the skin and produce results that last several hours to several days.