Information on hypertrichosis and excessive hair growth
Information on hypertrichosis and hair removal treatments
Hypertrichosis is an excessive hair disorder featuring abnormal hair density and length as compared to normal growth expected for the individuals’s age, ethnicity and sex. A diagnosis of hypertrichosis does not imply any particular hair distribution. Except in very rare cases there is no androgen hormone involvement in cases of hypertrichosis. In contrast, excessive hair growth diagnosed as hirsutism in women involves androgen hormone activity and a male pattern of hair growth on the chin, upper lip, and other areas where men have terminal hair growth. If you want to know more about hirsuitsm, see our sister web site www.hirsutism.com.
Hypertrichosis dot com has been written to provide you with information on hypertrichosis, what casues it, and how it is treated. Read on for a brief overview or click a link on the left to take you to more detailed information.
Introduction to hypertrichosis
There are significant differences in hair growth patterns between people of different ethnic backgrounds and age or sex groups. The growth that is normal for one group may be abnormal for another group and vice versa. These factors are considered in evaluating whether a hypertrichosis disorder does or does not exist.
Abnormal hair growth causes great embarrassment and distress to people since it disfigures their appearance. Removal of unwanted hair, called cosmetic treatment, is therefore an important part of the overall treatment regimen.
Though hypertrichosis is usually a cosmetic problem, it may also be a sign of an underlying medical problem. It can therefore be an aid to diagnosis of conditions that require treatment. Hence, familiarity with the causes of hypertrichosis is important.
Classification of hypertrichosis
Commonly, hypertrichosis is classified as generalized hypertrichosis or localized hypertrichosis. Generalized means excessive hair growth all over the body or at multiple sites on the body. Localized refers to abnormal hair growth at a single site or just a few sites. These two types are further sub-divided into congenital (present from birth) and acquired (develops over time) categories of hypertrichosis.
Types of hair involved
To understand hypertrichosis, it is necessary to be familiar with the three types of hairs that grow on humans.
Lanugo hairs: These are long, silky and light colored hairs which normally grow on embryos in the womb and are shed anytime from the seventh month of pregnancy to the first several months after birth.
Vellus hairs: These are short non-pigmented hairs, which after birth replace the lanugo hairs on all parts of the body except the scalp and eyebrows of a baby.
Terminal hairs are coarser and thicker hairs and usually pigmented. These hair follicles cover the scalp and eyebrows and, later with the onset of puberty, start to grow in the groin and underarm areas.
Generalized hypertrichosis can involve all three types of hair while localized hypertrichosis usually involves conversion of vellus hairs into terminal hairs.
Types of hypertrichosis
Generalized congenital hypertrichosis
This is a rare inherited disorder. In earlier times, the patients were considered an exotic "species", much prized for their curiosity value. At birth, the long and silky lanugo hairs, normally shed before or shortly after birth, remain on the infant’s entire body, sparing only the palms and soles. The growth is typically more on the face, ears and shoulders. In the documented cases, no reduction in hair growth was seen later in life.
A variant of generalized congenital hypertrichosis is congenital hypertrichosis lanuginosa (CHL) where the hair is fine, blond, lanugo type hair. The patients are normal except for abnormal dental eruptions. The hypertrichosis may persist, decrease or increase with age. Brachmann de Lange is a variant of CHL where the growth is less generalized and the infants have a particular appearance due to associated mental and growth retardation. Hair shedding begins in the first year of life starting at the trunk and progressing to the limbs.
Generalized acquired hypertrichosis
Acquired generalized hypertrichosis is commonly caused by drugs like phenytoin, cyclosporine A, and minoxidil among others. Hypertrichosis disappears once the drug intake is discontinued. The time taken depends on the growth site and is usually 3 months to a year. Less commonly, hypertrichosis is caused by head injuries, malnutrition, starvation and AIDS.
Generalized hypertrichosis is also caused by a class of disorders known as porphyries, which are often triggered by exposure to chemicals of which hexachlorobenzene is a common example. Excess growth tends to disappear once exposure ceases.
Localized congenital hypertrichosis
Localized hypertrichosis here is restricted to a single or just a few sites such as the back, elbows, ears and nevi. Excess hair on the back can be a sign of underlying neural abnormalities or spinal defects. Therefore, early daignosis treatment is critically important.
Excess hairs on the elbows are termed hypertrichosis cubiti. The growth becomes more prominent in early childhood and usually disappears partially or fully in adolescence.
Hairy pinna is excessive hair on the ears and is more common among older men. In babies, it can be associated with a diabetic mother. AIDS patients and diabetic patients can also have excess hair on their ears.
Hairy nevi are the most common hypertrichosis among babies. Additionally the nevi are often pigmented. It is usually not anindicator of any underlying abnormality.
Localized acquired hypertrichosis
These are transient hypertrichoses caused by a variety of injuries like trauma, irritation or inflammation, which transform vellus hairs into coarse terminal hairs as a repsonse to the local injury.
Becker’s nevus is a common disorder where sunburn or other injuries to the shoulder cause excess hair growth and pigmentation of the site. It heals with time and is more common among men. The application of plaster casts for broken bones often causes excess hair growth underneath the cast. AIDS is known to cause excess hair growth of the eyelashes, a disorder called trichomegaly.
Cosmetic treatment is usually undertaken, particularly for congenital hypertrichosis, where, unlike in many acquired hypertrichosis cases, the underlying problems cannot be cured. There is no single treatment for all hypertrichoses and patients. The site, nature and amount of growth, and the patients and their preferences are taken into account when deciding the most appropriate treatment method.
The common treatments are shaving, plucking, epilation, depilation, electrolysis and laser removal. Laser and electrolysis treatment approaches hold the promise of being permanent hair removal approaches. Other treatments are temporary and have to be repeated.
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