Hypertrichosis overview

Hypertrichosis is excessive hair growth on the body beyond what is typically expected for someone of the same age, race, and gender, excluding hair growth caused by excess male hormones (androgens).^1,2

Excessive hair growth can lead to emotional distress and embarrassment, especially when it is widespread.¹

Hypertrichosis can be present from birth (congenital) or develop later in life (acquired).²

Read on for a comprehensive review of available treatments, from temporary solutions like shaving and waxing to more permanent methods such as laser therapy and electrolysis.¹

Hypertrichosis causes and types

The origin of hypertrichosis remains unexplained.²

• Congenital hypertrichosis is thought to be a genetic condition that can be passed down through families (inherited) or arise due to spontaneous mutation²
• Acquired hypertrichosis lanuginose can sometimes be a symptom of a developing cancer known as malignant down, which is often confined to the face with long fine silky hair noticeable on the nose and eyelids, these sites are normally hairless, it’s not known why a cancer causes this excessive hair growth²

Generalised acquired hypertrichosis

Generalised acquired hypertrichosis may be associated with:²

• Malnutrition e.g. anorexia nervosa
• Malignancy
• Certain medications such as cyclosporine, phenytoin, androgenic steroids, and minoxidil
• Porphyria cutanea tarda

Types of generalised hypertrichosis

Universal congenital hypertrichosis

• The whole body is covered with a remarkable amount of long vellus-type hair, sparing only areas where no hair grows, including the palms, and mucosa¹

Congenital hypertrichosis lanuginosa

• It produces a different pattern of hair growth and characterises a distinct condition¹
• At birth, the entire body except for the hands and feet is covered with fine, light-coloured lanugo-type hair¹
• Within the first year, this hair begins to fall out, starting on the torso and then progressing to the arms and legs¹ 

Drug-induced hypertrichosis

• Phenytoin, a medication, can cause excessive hair growth after three months of use. This may be accompanied by acne and enlarged gums¹
• Excessive hair growth occurs in 60% of patients receiving cyclosporine treatment within the first six months¹
• Oral and, less commonly, topical minoxidil can cause excessive hair growth, mainly on the face and extremities. This effect is noticeable after a few weeks of treatment. Stopping the medication can reverse drug-induced hair growth within a few months to a year, depending on the hair growth cycle in the affected area (face: 3 months; arms: 1 year)¹
• Hepatic porphyria, caused by exposure to chemicals such as hexachlorobenzene, can lead to significant hair growth on the face and extremities. In a Turkish epidemic, excessive hair growth was so noticeable that affected individuals were nicknamed "monkey children"¹
• Head injuries and other brain disorders can cause excessive hair growth. While this was initially linked to phenytoin, it has also been observed in individuals with brain damage who have never taken this medication. This explains why some patients taking phenytoin lose their excess hair when the drug is stopped, while others do not
• Children with juvenile hypothyroidism may experience excessive hair growth, particularly on the back and outer surfaces of the limbs¹
• In addition to excessive eyelash growth (acquired trichomegaly), people with AIDS may also experience more widespread hair growth¹

Localized acquired hypertrichosis

Localized acquired hypertrichosis may be associated with:²

• Repetitive rubbing or scratching (lichen simplex)
• Increased vascularity
• Repeated application of minoxidil, potent topical steroids, iodine, psoralens (topical PUVA)

Hypertrichosis diagnosis

• The diagnosis of hypertrichosis is based on the individual's medical history, symptoms, and physical examination³
• By examining the location of the hair growth, hirsutism (excessive hair growth due to male hormones) can often be ruled out³
• Family history can help determine if the condition is inherited, while a review of other medical conditions or medications can identify potential causes³

Hypertrichosis hair removal management

Unwanted hair can be concealed by bleaching or removal through various physical methods such as trimming, shaving, plucking, or waxing, chemical procedures (depilatories), or electrosurgical epilation.¹

Bleaching

• Bleaching is a fast, simple, and painless method that can make unwanted hair less noticeable by partially or completely removing its natural pigment, lightening it to a yellowish tint¹
• This method is most suitable for treating localized areas of excessive pigmented hair on the face or arms of fair-skinned individuals, as yellow-bleached hair is highly visible against darker skin tones¹
• In some cases, bleaching can cause skin irritation¹

Trimming

• Trimming the hair is a suggested option for young children with both localized and generalised hypertrichosis, as it can make the hair in affected areas less noticeable without causing faster hair regrowth¹

Shaving

• While many women find shaving unacceptable for facial hair removal, most consider it an acceptable method for removing excess body hair¹
• It's seen as quick, effective, easy, and inexpensive. Contrary to popular belief, shaving does not affect the thickness or growth rate of individual hairs¹
• Daily shaving is necessary to maintain a desirable appearance¹
• Although dry or electric shaves are not as close as wet shaves, a dry electric razor has been used to effectively treat generalised hypertrichosis in newborns¹

Plucking

• Plucking is an effective but temporary hair removal method that is slow, time-consuming, and painful¹
• The hair regrows in about 2 weeks, which is longer than shaving¹
• It's suitable for removing individual, small groups, or scattered coarse hairs using tweezers¹
• Potential side effects of plucking include hyperpigmentation, folliculitis, scarring, ingrown hairs, and distorted follicles¹

Waxing

• Wax epilation involves applying cold, warm, or hot wax to hair-bearing areas and then removing it, pulling out the embedded hairs¹
• Waxing is an effective method for removing vellus hairs from all body areas and is affordable when carried out at home¹
• The main drawbacks are discomfort, poor removal of short hair, and skin irritation or folliculitis¹
• This method is too painful for children with hypertrichosis. Similar to hair plucking, the regrowth period is longer than shaving and requires repetition every 2-6 weeks¹

Hair removal using light sources and laser

• The desire for a quick and painless method of hair removal has led to the development of various laser and light-based technologies¹
• Several devices are now available, all of which operate on the principle of selective photothermolysis¹
• The melanin pigment in hair follicles acts as a chromophore, allowing for targeted destruction of hair follicles while leaving the surrounding skin unharmed¹
• By using deeply penetrating wavelengths between 600 nm and 1100 nm, melanin absorption can be utilised for selective photothermolysis of hair follicles¹

Examples of laser sources

• Ruby Laser
• Alexandrite Laser
• Diode Laser
• Neodynium: Yttrium-Aluminium-Garnet (Nd:YAG) Laser
• Intense Pulsed Light Source

Adverse effects of light source and laser treatment

• Erythema (redness) and perifollicular oedema (swelling around hair follicles) are common side effects of hair removal using light sources or laser techniques¹
• Crusting, blistering, hypopigmentation (loss of pigment), and hyperpigmentation (excess pigment) are less frequent and depend on skin colour and other factors¹
• Most complications are temporary, and their occurrence can be reduced by lightening the skin and avoiding sun exposure before laser treatment, effectively cooling the skin during treatment, and avoiding and protecting the skin from sun exposure after treatment¹

Hypertrichosis pharmacological treatment

Hypertrichosis treatment is divided into two main parts: systemic anti-androgen therapy and topical eflornithine, as follows:¹

Systemic anti-androgen therapy

• Because hypertrichosis is not caused by excess male hormones (androgens), anti-androgen therapy is not effective in treating it
• This is different from hirsutism, where excessive hair growth is either stimulated by excess androgen production or is related to the hair follicles' sensitivity to androgens.¹ Therefore, hormonal treatment for hirsutism focuses on suppressing androgen production or counteracting the biological effects of androgens with anti-androgen therapy¹
• Prepubertal hypertrichosis may be a type of hypertrichosis that, when observed in post-pubertal females, could be mistakenly assumed to be androgen-dependent, however, this form of excessive hair growth does not respond to anti-androgen therapy¹

Topical eflornithine

• A novel approved treatment for slowing excessive hair growth (without removing excess hair) is topical eflornithine¹
• Eflornithine is a specific and irreversible inhibitor of the enzyme ornithine decarboxylase, which is found in hair follicles and plays a crucial role in maintaining hair growth¹

Psychological and emotional support

• Hypertrichosis patients may suffer from depression, bullying, and other psychological crises that can affect their willingness to live especially females, and some individuals may even attempt suicide
• Considering the potential emotional distress associated with hypertrichosis, offering emotional support, education, and potentially referring individuals to mental health professionals may be a crucial part of the treatment plan
• If you are feeling suicidal, you can contact The Samaritans, among other mental health organisations for support

Summary

Hypertrichosis is excessive hair growth that can be present from birth (congenital) or develop later in life (acquired). It can lead to emotional distress and embarrassment. Although the exact cause remains unknown, it can be linked to genetic factors, medical conditions, medications, or environmental influences. Diagnosis typically involves a detailed medical and family history to identify potential causes. Treatment options include temporary methods like shaving, waxing, and bleaching, as well as more permanent methods such as laser therapy and electrolysis. Psychological support is essential for individuals suffering from hypertrichosis. Prevention is generally not possible as hypertrichosis is often genetic or due to factors beyond an individual's control. However, if it's related to medication use, it might be preventable by switching to an alternative medication if appropriate. 

FAQs

What is hypertrichosis?

Hypertrichosis is a condition characterised by excessive hair growth over the body beyond what is typically expected for someone of the same age, race, and gender.

What are the causes of hypertrichosis?

The causes of hypertrichosis vary, including genetic mutation, malnutrition, cancer, and drug-induced hypertrichosis. Other non-clinical factors such as race, age, and environmental conditions may also contribute to hypertrichosis.

What’s the difference between hirsutism and hypertrichosis?

Both conditions involve excessive hair growth, but hirsutism refers to male-pattern hair growth in women, like facial hair, while hypertrichosis is excessive hair growth anywhere on the body in both men and women.

How is hypertrichosis diagnosed?

Diagnosis usually includes a comprehensive medical history, physical examination, and possibly additional diagnostic tests such as blood tests or genetic testing, especially if other symptoms indicate an underlying health issue.

What are the treatment options for hypertrichosis?

Treatment options may include addressing underlying causes, and cosmetic hair removal techniques like shaving, waxing, laser therapy, and eflornithine. Psychological support can also be helpful.

What are the side effects of hair removal methods?

The side effects of hair removal include skin irritation, pigmentation, pain, redness, scarring, and infections.

Can hypertrichosis be prevented?

Since hypertrichosis is often genetic or caused by factors beyond an individual's control, prevention is generally not possible. However, if it's related to medication use, it might be preventable by using an alternative medication if appropriate.