Circumscribed hypertrichosis
Hypertrichosis occurs in both sexes. It is defined as excessive growth of hair on sites not normally hairy. The hairs may be of the lanugo or vellus type and some of these hairs evolve into terminal hairs. Hair may be excessive in density or length and the condition may be localized or generalized. The process is not androgen dependant.
The normal hair patterns have previously been discussed. Localized hypertrichosis occurs as an isolated finding or in association with a number of neurological, endocrino-logical and naevoid disorders.
Hairy ears
Hereditary development of coarse hairs on the pinna of the ear occurs most frequently and with the longest, most dense hairs in Indians. It first appears at around 20 years of age and thereafter increases in incidence and severity such that by the age of 70 years, 70% of men in Madras are affected. Normally only males are affected, and hypertrichosis of the pinna is believed to be a sex-linked recessive trait. The combination of hairy ears and azoospermia has been proposed as the only known Y chromosome-linked disorder.
Congenital hairy ears occur in babies born to diabetic mothers (unrelated to maternal diabetic control), babies with XYY syndrome and in some normal infants. Acquired hairy ears have been observed in AIDS, and often accompany trichomegaly of the eyelashes and eyebrows.
Hairy eyebrows
Extremely long eyebrows or eyelash hair, or eyebrows that join in the centre (synophrys) are usually familial. In infants it may occur as a localized problem or rarely as part of a syndrome such as Cornelia de Lange, Rubins tein-Taybi, congenital hypertrichosis lanuginosa or congenital trichomegaly with dwarfism, mental retardation or pigmentary degeneration of the retina. Long eyebrows are commonly the most pronounced aspect of the drug-induced acquired hypertrichosis occurring with cyclosporin, minoxidil and diazoxide. AIDS can also induce eyebrow growth.
Hairy palms
Localized patches of hair on the palms and soles have been reported in two families as an autosomal dominant trait. The hypertrichosis was associated with increased pigmentation and textural changes in the skin. This could represent hypertrichosis in association with a connective tissue hamartoma as histology shows an increased amount of disorganized elastic tissue.
Hairy elbows
In familial hypertrichosis cubiti, excessive hair growth develops in infancy over the lower third of the upper arm and the upper third of the forearms. The hypertrichosis is progressive for a few years before partially regressing around puberty. The mode of inheritance is uncertain, and both autosomal recessive and autosomal dominant patterns have been suggested. An association with short stature is seen in 10%. An increased proportion of anagen hairs (>90%) are seen histologically, suggesting that this condition is caused by prolongation of anagen.
Becker's naevus
This condition is an androgen-mediated hyperplasia that first appears at puberty as a unilateral localized area of hyperpigmentation. In 50% of cases it is followed by hypertrichosis. The hairs are predominantly terminal hairs. Acne occasionally develops within a Becker's naevus. The incidence is about 0.5% and the male to female ratio is 10 :1. About half occur on the shoulder and the rest on the trunk and a few on the limbs or face. Multiple lesions are rare as are familial cases. The term naevus requires qualification, as there is no increase in the number of melanocytes and histology simply shows acanthosis with basal hyperpigmentation. An increase in smooth muscle bundles in the dermis is sometimes noticed.
Uncommon associated abnormalities include ipsilateral breast hypoplasia, spina bifida, pectus carinatum, accessory nipples, morphoea and ipsilateral leg hyperplasia. Electrolysis has been used with mixed success to treat the hypertrichosis, but the pigmentation is very difficult to treat.
Congenital melanocytic naevus
Both congenital and acquired naevi can develop hypertrichosis, usually consisting of terminal hairs. The presence of hairs does not help to determine if a pigmented lesion is benign or malignant as a melanoma may arise at the edge of a hairy naevus and in addition loss of hairs tends to be a late feature in the development of melanoma. Congenital pigmented hairy naevi are probably the commonest cause of localized hypertrichosis in infancy. The German term Tierfell-nevus (animal skin naevus) has been used to describe a particularly hairy variant and is an apt morphological description.
Faun tail
A congenital midline dorsal patch of hypertrichosis or faun tail is an important clue to a possible occult spinal abnormality that may in time produce neurological deficits. It consists of a tuft of long silky hair in the sacral area usually overlying normal skin.
Occasionally there will be a sinus or a dimple within the faun tail and rarely a lipoma or a capillary naevus will be found beneath it. Sinuses are usually 1-2 mm wide and can connect directly with the spinal cord. They are a potential portal of entry for infection and they can be associated with a cystic dilatation within the spinal cord that produces neurological deficits.
Spinal dysraphism (failure of spinal fusion) occurs beneath the faun tail four times more frequently in girls than boys. In association with this the cord can be transfixed by a bony spicule (diastematomyelia), or the cauda equina may be tethered by fibrous cords. With time this produces traction damage to the cord as a result of differential growth of the vertebra and the cord. Neurological deficits are not present at birth, but gradually develop over the first 5 years. If identified early permanent damage can be prevented by prophylactic surgery.
Midline hypertrichosis can occur anywhere along the back associated with cervical, thoracic or lumbar dysraphism. The stimulant for hair growth is presumably a growth factor secreted by neural tissue, however, none has been identified.
Hair collar sign
In 1989 Commen described a distinctive collar of hypertrophic hairs that palisaded around a bald nodule containing heterotopic brain tissue. The nodule usually overlies an embryonic fusion line. The collar of long terminal hairs grows faster, earlier and longer than the rest of the infant's scalp hair. It has also been described in a number of other neuroectodermal defects including dermoid cysts, dermal sinus tumours, encephalocele, sequestrated meningocele, and leptomeningocele. If the cyst fills when the baby cries this suggests an intracerebral communication.
The hair collar sign is an important clue alerting the clinician to the possibility that the lesions extend intracranially and a computed tomography (CT) or magnetic resonance imaging (MRI) scan is required, particularly if a biopsy is being considered. Ultimately the central nodule will flatten to form a circular smooth patch of rubbery hairless skin and the collar of hypertrophic hair will blend in with the adjacent scalp hair as it grows. The palisading hairs are then discernible only on close inspection.
Naevoid hypertrichosis
Hypertrichosis of a limited extent occurs as an isolated developmental defect. It can also occur over a patch of thickened parchment-like skin or complicate a benign tumour such as a neurofibroma or a smooth muscle hamartoma. Smooth muscle hamartomas show transient piloerection when stroked.
Congenital hemihypertrophy with hypertrichosis
This rare syndrome present at birth becomes more pronounced at puberty. Other possible associations include mental retardation, multiple naevi, telangiectases and internal malignancies.
Congenital hypertrichosis lanuginosa
This rare autosomal dominant disorder is characterized by the retention and continued synchronized growth of fetal lanugo hair. Names such as apeman, dogman, manlion and wildman were used in older literature to describe this condition. The incidence is estimated at 1 in 109 live births.
Clinical features and investigation
The infants are either born with or develop within the first few months, a fur consisting of a thick coat of fine silky hair that can be up to 5 cm long and which covers the entire nonglabrous surface. The terminal scalp hairs are easily distinguished from the extensive silvery-grey body hair that only spares the palms, soles, lips, glans penis and the terminal phalanges.
During childhood the condition usually progresses, but occasionally it may regress or even stay the same. At puberty there is growth of sexual hair but without the usual conversion to terminal hair. Thus longer lanugo hairs grow in the pubic, axillary and beard areas.
There are generally no associated features, although neonatal teeth and pyloric stenosis have been described. This condition should be distinguished from hypertrichosis with gingival hyperplasia (see below).
Management
The striking appearance of affected individuals has lead to their exploitation over the centuries as side-show freaks. Psychological support of the patient and family is an important part of the management. Shaving is often the only feasible means of controlling the hair growth at present, although the new, non-q-switched ruby lasers may prove to be effective.
Key points
A complete pelage of fine silvery hair makes this hereditary condition unmistakable.
Other congenital syndromes with prominent hypertrichosis
Hypertrichosis with gingival fíbromatosis
Hypertrichosis in association with gingival hyperplasia and epilepsy was recognized as a rare autosomal dominant condition before the introduction of phenytoin. Eighty per cent of cases are familial and the condition has been associated with Cowden's disease, suggesting genetic linkage.
The hypertrichosis usually appears at birth and mainly affects the face, arms and back. During infancy it mimics congenital hypertrichosis lanuginosa, but the hair darkens with puberty. The gingival fíbromatosis may not be noticed until the age of 10 years, but usually is detected earlier if the epilepsy is severe. The hypertrophy of the gums buries emerging teeth in a mass of redundant tissue. It has been suggested that phenytoin induced gingival hyperplasia relates to poor dental hygiene, however, it is not known if the same holds true for familial cases.
Hypertrichosis with osteochondrodysplasia
This is an autosomal recessive condition combining generalized congenital hypertrichosis with a constellation of skeletal abnormalities that include a narrow thorax, generalized osteopaenia, hypoplastic pubic rami and premature growth arrest of the femur.
X-linked hypertrichosis
This X-linked dominant condition is characterized by hypertrichosis predominantly over the face, back, upper chest and pubic regions. The facial growth obscures the eyebrows and sometimes only the eyes and lips are visible beneath a dense growth of dark black hair.
This is a nonfamilial hypertrichosis, present at birth, that increases in severity during early childhood. As it occurs equally in people of Asian or European descent, the term racial hypertrichosis is inappropriate. There is growth of terminal hairs on the temples spreading across the forehead, bushy eyebrows, and marked growth on the upper back and proximal limbs. In contrast to the synchronized growth of lanugo hairs in congenital hypertrichosis lanuginosa, the hair growth in this condition is unsynchronized. In adolescence this form of hypertrichosis is often confused with hirsutes. Misdiagnosis of this condition is the reason why some so-called 'hirsute' women fail to respond to antiandrogen therapy.
Coffin-Siris syndrome
This syndrome combines generalized congenital hypertrichosis, prominent eyebrows and eyelashes and sparse scalp hair with profound mental and growth retardation and congenital absence of the distal phalanges and nails of the fifth fingers and toes. Characteristic facies and abnormal dentition, have also been described. The inheritance of this syndrome has not yet been established.
Cornelia de Lange syndrome
Hypertrichosis is a constant and distinctive feature of this rare syndrome. In addition to the mild generalized hypertrichosis there is abundant scalp hair with low frontal and nuchal hair lines. The eyebrows are bushy and meet in the centre and the eyelashes are long and curled. Other features are variable and include physical and mental retardation, characteristic facies, cutis marmorata, short digits, syndactyly of the second and third toes, a high arched palate, an unusual cry, increased susceptibility to infection and a constellation of ocular, dental and skeletal abnormalities.
Leprechaunism
This entity is characterized by grotesque elfin facies with thick large lips, large low set ears, breast enlargement and prominent genitalia. Absence of subcutaneous tissue gives rise to excessive folding of the skin. Generalized hypertrichosis is seen in three-quarters of cases and is most prominent on the forehead and cheeks.
Other syndromes that produce hypertrichosis
- Gorlin syndrome, with patent ductus arteriosus, hypoplasia of the teeth, eyes and labia majora and craniofacial dysostosis;
- Lissencephaly, with growth and mental retardation and a smooth brain without sulci and gyri;
- Rubinstein-Taybi syndrome with broad thumbs, physical and mental retardation cryptorchidism and characteristic facies;
- Schinzel-Gideon syndrome with club feet, skeletal abnormalities and characteristic facies with redundant folds of skin overlying a short neck;
- Lawrence-Seip syndrome with congenital lipoatrophy and juvenile onset insulin-resistant diabetes, hyperlipi-daemia and hepatosplenomegaly;
- Hunter's, Hurler's and Winchester's mucopolysacchari-doses syndromes;
- Fetal alcohol syndrome with mental and physical retardation, microcephaly, cardiac anomalies, joint defects, unusual facies and capillary haemangiomas.
- POEMS syndrome is an acronym for peripheral neuropathy, organomegaly, endocrine dysfunction, monoclonal gammopathy and skin changes. The main skin changes include hypertrichosis on the extensor surfaces, malar region and forehead, hyperpigmentation and oedema. Scarring alopecia on the abdomen has been described.
- Wardenburg's syndrome is associated with terminal hair on the tip of the nose and a beard that extends over the entire surface of the cheeks.
Acquired hypertrichosis lanuginosa
This rare condition is characterized by the rapid growth of long, fine, downy lanugo hairs particularly over the face, but also on the body. It is a paraneoplastic phenomenon often seen late in the course of an internal malignancy; a so-called malignant down. The importance of this condition is that it may be the presenting sign of the malignancy and can appear up to 2 years prior to other manifestations. A hair growth factor produced by the tumour has been postulated but not identified.
Clinical features and investigation
Acquired hypertrichosis lanuginosa has an age range of 19-69, with a female predominance of 3:1. The extent and degree of lanuginose transformation varies considerably. In early cases the growth of down on the forehead and temples is the only abnormality. In others the striking feature is the rapidity with which obvious hypertrichosis develops. Hair appears on the forehead, eyelids, nose, ears and torso giving the patient a simian appearance. The palms, soles, pubic regions and scalp tend to be spared. Balding scalps are rejuvenated by a dense growth of hair, albeit lighter and finer than the neighbouring hair. Hairs may grow as fast as 2.5 cm per week and achieve a length of 15 cm, but more commonly are about 1 cm long. Other cutaneous abnormalities that may coexist include keratotic lesions on the palms, soles and limbs, glossitis, acquired ichthyosis and acanthosis nigricans with tripe palms.
The malignancies most often associated with this condition are carcinoma of the lung, colon, uterus and lymphoma.
Management
In order to detect an occult cancer a detailed history and examination, including rectal and pelvic examination with a cervical smear are required. This should be complemented by a full blood examination, a mammogram, colonoscopy and chest X-ray. If available an abdominal and pelvic CT scan can be performed, however, an abdominal ultrasound may suffice. If these investigations are negative, continued vigilance is required and a thorough examination should be repeated regularly.
Successful removal of the underlying cancer has resulted in regression of the hypertrichosis.
Key points
Malignant down occurring on the face late in the course of a malignancy is common. Rarely, the hypertrichosis predates the diagnosis of the cancer. In these cases the rapid appearance of fine downy hairs on the body and face of an apparently healthy person should alert the physician to the probable presence of an occult malignancy.
Other acquired syndromes with prominent hypertrichosis
Porphyria
Hypertrichosis occurs in all forms of porphyria except acute intermittent porphyria. It is most prominent in congenital porphyria, certain forms of acquired porphyria cutánea tarda (PCT) and erythropoietic porphyria. Photo-sensitivity plays a role, particularly as the hypertrichosis usually appears on the exposed sites such as the face and hands.
The facial hair is most prominent along the temples, cheeks, eyebrows and hairline and the hair structure function is generally soft and pigmented. In black people hypertrichosis is an important sign of PCT as blistering is uncommon.
The combination of photosensitivity, milia and scarring on the hands or face and hypertrichosis presents little diagnostic difficulty and requires a blood, urine and faecal porphyrin screen to confirm the diagnosis and elucidate the subtype. The absence of hypertrichosis in pseudoporphyria, epider-molysis bullosa acquisita, Hutchinson's summer prurigo, drug-induced photosensitivity, chronic renal failure and frusemide therapy allow these clinical look-alikes of PCT to be distinguished.
Thyroid disease
Diffuse hypertrichosis affecting the temples, back, shoulders and limbs occurs as a manifestation of congenital hypothyroidism and is often associated with converging eyebrows. It usually remits with thyroxine therapy. At puberty the pubic and axillary hair fail to develop. More usually hypothyroidism is associated with a diffuse alopecia of the scalp. In Grave's disease localized hypertrichosis can also occur over plaques of pretibial myxoedema.
Anorexia nervosa
Malnutrition from malabsorption, starvation and anorexia nervosa can cause hypertrichosis of the limbs and trunk that in some cases is striking.
Drug-induced hypertrichosis
It is important to distinguish between iatrogenic hirsutism, where new hair occurs in a male sexual distribution and drug-induced hypertrichosis, which is generalized. Minoxidil, diazoxide, phenytoin, cyclosporin A, psoralens and ultraviolet A therapy (PUVA), prednisolone, streptomycin, acetozolamide, benoxaprofen, penicillamine and fenoterol have all been reported to induce hypertrichosis in a proportion of users. The mechanism of hair induction is not known and the same mechanism is not involved in all cases.
Minoxidil and diazoxide are vasodilators that produce hypertrichosis in 80% of recipients predominantly over the face, shoulders, arms and legs. The hair falls out several months after cessation of therapy. Minoxidil is also active topically and has been used to treat andro-genetic alopecia. The resultant hairs that appear on the scalp after oral minoxidil are often fine, poorly pigmented indeterminate type hairs of marginal cosmetic significance.
Cyclosporin A, an immune modulator, may induce a switch from telogen to anagen in hair. In humans it produces a diffuse growth of hair across the shoulders, back, upper extremities, face, scalp, eyebrows and earlobes. It begins within a few weeks of taking cyclosporin in upwards of 60% of recipients. Hypertrichosis is more common in childhood and adolescence and reverses about 1 month after stopping treatment.
In about 10% of people receiving phenytoin an excessive growth of hair develops after 1-2 months across the extensor aspects of the limbs and subsequently on the face and trunk. It remits within a year of cessation of therapy. This hypertrichosis does not appear to be related to dose or duration of therapy.
Prolonged administration of cortisone can induce hypertrichosis that is most marked on the forehead, the temples and the sides of the cheeks. It also occurs on the back and the extensor surface of the arms. Steroid-induced acne may be associated.
PUVA induces hair in exposed sites as does benoxaprofen following the induction of drug-induced photosensitivity. Penicillamine tends to produce lengthening and coarsening of hair on the trunk and limbs.
Hypertrichosis occurs in both sexes. It is defined as excessive growth of hair on sites not normally hairy. The hairs may be of the lanugo or vellus type and some of these hairs evolve into terminal hairs. Hair may be excessive in density or length and the condition may be localized or generalized. The process is not androgen dependant.
The normal hair patterns have previously been discussed. Localized hypertrichosis occurs as an isolated finding or in association with a number of neurological, endocrino-logical and naevoid disorders.
Hairy ears
Hereditary development of coarse hairs on the pinna of the ear occurs most frequently and with the longest, most dense hairs in Indians. It first appears at around 20 years of age and thereafter increases in incidence and severity such that by the age of 70 years, 70% of men in Madras are affected. Normally only males are affected, and hypertrichosis of the pinna is believed to be a sex-linked recessive trait. The combination of hairy ears and azoospermia has been proposed as the only known Y chromosome-linked disorder.
Congenital hairy ears occur in babies born to diabetic mothers (unrelated to maternal diabetic control), babies with XYY syndrome and in some normal infants. Acquired hairy ears have been observed in AIDS, and often accompany trichomegaly of the eyelashes and eyebrows.
Hairy eyebrows
Extremely long eyebrows or eyelash hair, or eyebrows that join in the centre (synophrys) are usually familial. In infants it may occur as a localized problem or rarely as part of a syndrome such as Cornelia de Lange, Rubins tein-Taybi, congenital hypertrichosis lanuginosa or congenital trichomegaly with dwarfism, mental retardation or pigmentary degeneration of the retina. Long eyebrows are commonly the most pronounced aspect of the drug-induced acquired hypertrichosis occurring with cyclosporin, minoxidil and diazoxide. AIDS can also induce eyebrow growth.
Hairy palms
Localized patches of hair on the palms and soles have been reported in two families as an autosomal dominant trait. The hypertrichosis was associated with increased pigmentation and textural changes in the skin. This could represent hypertrichosis in association with a connective tissue hamartoma as histology shows an increased amount of disorganized elastic tissue.
Hairy elbows
In familial hypertrichosis cubiti, excessive hair growth develops in infancy over the lower third of the upper arm and the upper third of the forearms. The hypertrichosis is progressive for a few years before partially regressing around puberty. The mode of inheritance is uncertain, and both autosomal recessive and autosomal dominant patterns have been suggested. An association with short stature is seen in 10%. An increased proportion of anagen hairs (>90%) are seen histologically, suggesting that this condition is caused by prolongation of anagen.
Becker's naevus
This condition is an androgen-mediated hyperplasia that first appears at puberty as a unilateral localized area of hyperpigmentation. In 50% of cases it is followed by hypertrichosis. The hairs are predominantly terminal hairs. Acne occasionally develops within a Becker's naevus. The incidence is about 0.5% and the male to female ratio is 10 :1. About half occur on the shoulder and the rest on the trunk and a few on the limbs or face. Multiple lesions are rare as are familial cases. The term naevus requires qualification, as there is no increase in the number of melanocytes and histology simply shows acanthosis with basal hyperpigmentation. An increase in smooth muscle bundles in the dermis is sometimes noticed.
Uncommon associated abnormalities include ipsilateral breast hypoplasia, spina bifida, pectus carinatum, accessory nipples, morphoea and ipsilateral leg hyperplasia. Electrolysis has been used with mixed success to treat the hypertrichosis, but the pigmentation is very difficult to treat.
Congenital melanocytic naevus
Both congenital and acquired naevi can develop hypertrichosis, usually consisting of terminal hairs. The presence of hairs does not help to determine if a pigmented lesion is benign or malignant as a melanoma may arise at the edge of a hairy naevus and in addition loss of hairs tends to be a late feature in the development of melanoma. Congenital pigmented hairy naevi are probably the commonest cause of localized hypertrichosis in infancy. The German term Tierfell-nevus (animal skin naevus) has been used to describe a particularly hairy variant and is an apt morphological description.
Faun tail
A congenital midline dorsal patch of hypertrichosis or faun tail is an important clue to a possible occult spinal abnormality that may in time produce neurological deficits. It consists of a tuft of long silky hair in the sacral area usually overlying normal skin.
Occasionally there will be a sinus or a dimple within the faun tail and rarely a lipoma or a capillary naevus will be found beneath it. Sinuses are usually 1-2 mm wide and can connect directly with the spinal cord. They are a potential portal of entry for infection and they can be associated with a cystic dilatation within the spinal cord that produces neurological deficits.
Spinal dysraphism (failure of spinal fusion) occurs beneath the faun tail four times more frequently in girls than boys. In association with this the cord can be transfixed by a bony spicule (diastematomyelia), or the cauda equina may be tethered by fibrous cords. With time this produces traction damage to the cord as a result of differential growth of the vertebra and the cord. Neurological deficits are not present at birth, but gradually develop over the first 5 years. If identified early permanent damage can be prevented by prophylactic surgery.
Midline hypertrichosis can occur anywhere along the back associated with cervical, thoracic or lumbar dysraphism. The stimulant for hair growth is presumably a growth factor secreted by neural tissue, however, none has been identified.
Hair collar sign
In 1989 Commen described a distinctive collar of hypertrophic hairs that palisaded around a bald nodule containing heterotopic brain tissue. The nodule usually overlies an embryonic fusion line. The collar of long terminal hairs grows faster, earlier and longer than the rest of the infant's scalp hair. It has also been described in a number of other neuroectodermal defects including dermoid cysts, dermal sinus tumours, encephalocele, sequestrated meningocele, and leptomeningocele. If the cyst fills when the baby cries this suggests an intracerebral communication.
The hair collar sign is an important clue alerting the clinician to the possibility that the lesions extend intracranially and a computed tomography (CT) or magnetic resonance imaging (MRI) scan is required, particularly if a biopsy is being considered. Ultimately the central nodule will flatten to form a circular smooth patch of rubbery hairless skin and the collar of hypertrophic hair will blend in with the adjacent scalp hair as it grows. The palisading hairs are then discernible only on close inspection.
Naevoid hypertrichosis
Hypertrichosis of a limited extent occurs as an isolated developmental defect. It can also occur over a patch of thickened parchment-like skin or complicate a benign tumour such as a neurofibroma or a smooth muscle hamartoma. Smooth muscle hamartomas show transient piloerection when stroked.
Congenital hemihypertrophy with hypertrichosis
This rare syndrome present at birth becomes more pronounced at puberty. Other possible associations include mental retardation, multiple naevi, telangiectases and internal malignancies.
Congenital hypertrichosis lanuginosa
This rare autosomal dominant disorder is characterized by the retention and continued synchronized growth of fetal lanugo hair. Names such as apeman, dogman, manlion and wildman were used in older literature to describe this condition. The incidence is estimated at 1 in 109 live births.
Clinical features and investigation
The infants are either born with or develop within the first few months, a fur consisting of a thick coat of fine silky hair that can be up to 5 cm long and which covers the entire nonglabrous surface. The terminal scalp hairs are easily distinguished from the extensive silvery-grey body hair that only spares the palms, soles, lips, glans penis and the terminal phalanges.
During childhood the condition usually progresses, but occasionally it may regress or even stay the same. At puberty there is growth of sexual hair but without the usual conversion to terminal hair. Thus longer lanugo hairs grow in the pubic, axillary and beard areas.
There are generally no associated features, although neonatal teeth and pyloric stenosis have been described. This condition should be distinguished from hypertrichosis with gingival hyperplasia (see below).
Management
The striking appearance of affected individuals has lead to their exploitation over the centuries as side-show freaks. Psychological support of the patient and family is an important part of the management. Shaving is often the only feasible means of controlling the hair growth at present, although the new, non-q-switched ruby lasers may prove to be effective.
Key points
A complete pelage of fine silvery hair makes this hereditary condition unmistakable.
Other congenital syndromes with prominent hypertrichosis
Hypertrichosis with gingival fíbromatosis
Hypertrichosis in association with gingival hyperplasia and epilepsy was recognized as a rare autosomal dominant condition before the introduction of phenytoin. Eighty per cent of cases are familial and the condition has been associated with Cowden's disease, suggesting genetic linkage.
The hypertrichosis usually appears at birth and mainly affects the face, arms and back. During infancy it mimics congenital hypertrichosis lanuginosa, but the hair darkens with puberty. The gingival fíbromatosis may not be noticed until the age of 10 years, but usually is detected earlier if the epilepsy is severe. The hypertrophy of the gums buries emerging teeth in a mass of redundant tissue. It has been suggested that phenytoin induced gingival hyperplasia relates to poor dental hygiene, however, it is not known if the same holds true for familial cases.
Hypertrichosis with osteochondrodysplasia
This is an autosomal recessive condition combining generalized congenital hypertrichosis with a constellation of skeletal abnormalities that include a narrow thorax, generalized osteopaenia, hypoplastic pubic rami and premature growth arrest of the femur.
X-linked hypertrichosis
This X-linked dominant condition is characterized by hypertrichosis predominantly over the face, back, upper chest and pubic regions. The facial growth obscures the eyebrows and sometimes only the eyes and lips are visible beneath a dense growth of dark black hair.
This is a nonfamilial hypertrichosis, present at birth, that increases in severity during early childhood. As it occurs equally in people of Asian or European descent, the term racial hypertrichosis is inappropriate. There is growth of terminal hairs on the temples spreading across the forehead, bushy eyebrows, and marked growth on the upper back and proximal limbs. In contrast to the synchronized growth of lanugo hairs in congenital hypertrichosis lanuginosa, the hair growth in this condition is unsynchronized. In adolescence this form of hypertrichosis is often confused with hirsutes. Misdiagnosis of this condition is the reason why some so-called 'hirsute' women fail to respond to antiandrogen therapy.
Coffin-Siris syndrome
This syndrome combines generalized congenital hypertrichosis, prominent eyebrows and eyelashes and sparse scalp hair with profound mental and growth retardation and congenital absence of the distal phalanges and nails of the fifth fingers and toes. Characteristic facies and abnormal dentition, have also been described. The inheritance of this syndrome has not yet been established.
Cornelia de Lange syndrome
Hypertrichosis is a constant and distinctive feature of this rare syndrome. In addition to the mild generalized hypertrichosis there is abundant scalp hair with low frontal and nuchal hair lines. The eyebrows are bushy and meet in the centre and the eyelashes are long and curled. Other features are variable and include physical and mental retardation, characteristic facies, cutis marmorata, short digits, syndactyly of the second and third toes, a high arched palate, an unusual cry, increased susceptibility to infection and a constellation of ocular, dental and skeletal abnormalities.
Leprechaunism
This entity is characterized by grotesque elfin facies with thick large lips, large low set ears, breast enlargement and prominent genitalia. Absence of subcutaneous tissue gives rise to excessive folding of the skin. Generalized hypertrichosis is seen in three-quarters of cases and is most prominent on the forehead and cheeks.
Other syndromes that produce hypertrichosis
- Gorlin syndrome, with patent ductus arteriosus, hypoplasia of the teeth, eyes and labia majora and craniofacial dysostosis;
- Lissencephaly, with growth and mental retardation and a smooth brain without sulci and gyri;
- Rubinstein-Taybi syndrome with broad thumbs, physical and mental retardation cryptorchidism and characteristic facies;
- Schinzel-Gideon syndrome with club feet, skeletal abnormalities and characteristic facies with redundant folds of skin overlying a short neck;
- Lawrence-Seip syndrome with congenital lipoatrophy and juvenile onset insulin-resistant diabetes, hyperlipi-daemia and hepatosplenomegaly;
- Hunter's, Hurler's and Winchester's mucopolysacchari-doses syndromes;
- Fetal alcohol syndrome with mental and physical retardation, microcephaly, cardiac anomalies, joint defects, unusual facies and capillary haemangiomas.
- POEMS syndrome is an acronym for peripheral neuropathy, organomegaly, endocrine dysfunction, monoclonal gammopathy and skin changes. The main skin changes include hypertrichosis on the extensor surfaces, malar region and forehead, hyperpigmentation and oedema. Scarring alopecia on the abdomen has been described.
- Wardenburg's syndrome is associated with terminal hair on the tip of the nose and a beard that extends over the entire surface of the cheeks.
Acquired hypertrichosis lanuginosa
This rare condition is characterized by the rapid growth of long, fine, downy lanugo hairs particularly over the face, but also on the body. It is a paraneoplastic phenomenon often seen late in the course of an internal malignancy; a so-called malignant down. The importance of this condition is that it may be the presenting sign of the malignancy and can appear up to 2 years prior to other manifestations. A hair growth factor produced by the tumour has been postulated but not identified.
Clinical features and investigation
Acquired hypertrichosis lanuginosa has an age range of 19-69, with a female predominance of 3:1. The extent and degree of lanuginose transformation varies considerably. In early cases the growth of down on the forehead and temples is the only abnormality. In others the striking feature is the rapidity with which obvious hypertrichosis develops. Hair appears on the forehead, eyelids, nose, ears and torso giving the patient a simian appearance. The palms, soles, pubic regions and scalp tend to be spared. Balding scalps are rejuvenated by a dense growth of hair, albeit lighter and finer than the neighbouring hair. Hairs may grow as fast as 2.5 cm per week and achieve a length of 15 cm, but more commonly are about 1 cm long. Other cutaneous abnormalities that may coexist include keratotic lesions on the palms, soles and limbs, glossitis, acquired ichthyosis and acanthosis nigricans with tripe palms.
The malignancies most often associated with this condition are carcinoma of the lung, colon, uterus and lymphoma.
Management
In order to detect an occult cancer a detailed history and examination, including rectal and pelvic examination with a cervical smear are required. This should be complemented by a full blood examination, a mammogram, colonoscopy and chest X-ray. If available an abdominal and pelvic CT scan can be performed, however, an abdominal ultrasound may suffice. If these investigations are negative, continued vigilance is required and a thorough examination should be repeated regularly.
Successful removal of the underlying cancer has resulted in regression of the hypertrichosis.
Key points
Malignant down occurring on the face late in the course of a malignancy is common. Rarely, the hypertrichosis predates the diagnosis of the cancer. In these cases the rapid appearance of fine downy hairs on the body and face of an apparently healthy person should alert the physician to the probable presence of an occult malignancy.
Other acquired syndromes with prominent hypertrichosis
Porphyria
Hypertrichosis occurs in all forms of porphyria except acute intermittent porphyria. It is most prominent in congenital porphyria, certain forms of acquired porphyria cutánea tarda (PCT) and erythropoietic porphyria. Photo-sensitivity plays a role, particularly as the hypertrichosis usually appears on the exposed sites such as the face and hands.
The facial hair is most prominent along the temples, cheeks, eyebrows and hairline and the hair structure function is generally soft and pigmented. In black people hypertrichosis is an important sign of PCT as blistering is uncommon.
The combination of photosensitivity, milia and scarring on the hands or face and hypertrichosis presents little diagnostic difficulty and requires a blood, urine and faecal porphyrin screen to confirm the diagnosis and elucidate the subtype. The absence of hypertrichosis in pseudoporphyria, epider-molysis bullosa acquisita, Hutchinson's summer prurigo, drug-induced photosensitivity, chronic renal failure and frusemide therapy allow these clinical look-alikes of PCT to be distinguished.
Thyroid disease
Diffuse hypertrichosis affecting the temples, back, shoulders and limbs occurs as a manifestation of congenital hypothyroidism and is often associated with converging eyebrows. It usually remits with thyroxine therapy. At puberty the pubic and axillary hair fail to develop. More usually hypothyroidism is associated with a diffuse alopecia of the scalp. In Grave's disease localized hypertrichosis can also occur over plaques of pretibial myxoedema.
Anorexia nervosa
Malnutrition from malabsorption, starvation and anorexia nervosa can cause hypertrichosis of the limbs and trunk that in some cases is striking.
Drug-induced hypertrichosis
It is important to distinguish between iatrogenic hirsutism, where new hair occurs in a male sexual distribution and drug-induced hypertrichosis, which is generalized. Minoxidil, diazoxide, phenytoin, cyclosporin A, psoralens and ultraviolet A therapy (PUVA), prednisolone, streptomycin, acetozolamide, benoxaprofen, penicillamine and fenoterol have all been reported to induce hypertrichosis in a proportion of users. The mechanism of hair induction is not known and the same mechanism is not involved in all cases.
Minoxidil and diazoxide are vasodilators that produce hypertrichosis in 80% of recipients predominantly over the face, shoulders, arms and legs. The hair falls out several months after cessation of therapy. Minoxidil is also active topically and has been used to treat andro-genetic alopecia. The resultant hairs that appear on the scalp after oral minoxidil are often fine, poorly pigmented indeterminate type hairs of marginal cosmetic significance.
Cyclosporin A, an immune modulator, may induce a switch from telogen to anagen in hair. In humans it produces a diffuse growth of hair across the shoulders, back, upper extremities, face, scalp, eyebrows and earlobes. It begins within a few weeks of taking cyclosporin in upwards of 60% of recipients. Hypertrichosis is more common in childhood and adolescence and reverses about 1 month after stopping treatment.
In about 10% of people receiving phenytoin an excessive growth of hair develops after 1-2 months across the extensor aspects of the limbs and subsequently on the face and trunk. It remits within a year of cessation of therapy. This hypertrichosis does not appear to be related to dose or duration of therapy.
Prolonged administration of cortisone can induce hypertrichosis that is most marked on the forehead, the temples and the sides of the cheeks. It also occurs on the back and the extensor surface of the arms. Steroid-induced acne may be associated.
PUVA induces hair in exposed sites as does benoxaprofen following the induction of drug-induced photosensitivity. Penicillamine tends to produce lengthening and coarsening of hair on the trunk and limbs.