User:Kdang0927/Prepubertal hypertrichosis

Pathophysiology
Background

The pathophysiology of prepubertal hypertrichosis can be attributed to increased concentrations of testosterone in the body. The elevated testosterone levels can lead to excessive hair growth all over the body during childhood. The most affected area can be on the face, back and those areas closer to the trunk of the body. A special characteristic to be screened for prepubertal hypertrichosis is in the instance of the growth of thick hair "in the setting of the slow, progressive development of hypertrichosis."

Those who were born with hypertrichosis with "reduced subcutaneous fat may indicate a diagnosis of leprechaunism, a lethal condition which is also associated with an unusual facial appearance, severe intrauterine and postnatal growth retardation, and hyperinsulinemia with hyperplasia of the pancreatic beta cells as a result of an insulin receptor defect."

Causes

The causes of prepubertal hypertrichosis can be due to a variety of factors such as medications, genetic disorders, and eating disorders, particularly anorexia nervosa. For example, during pregnancy, if the mother is taking a medication that may cause a side effect or if they are consuming alcohol, that their baby could be put at risk of developing hypertrichosis.

Psychological Impact

Those with prepubertal hypertrichosis can experience widespread hair growth throughout the body that can become more noticeable during childhood.

Management
The degree of management depends on the severity and location of the hypertrichosis as well as the psychosocial needs of the child, their family, and society. The management strategies for controlling and removing the excessive hair growth which include physical management strategies such as shaving, trimming, waxing, and tweezing, chemical strategies such as bleaching or use of chemical depilatories, the use of light sources in laser hair removal, intense pulse light therapy, and electrolysis. More specifically, depilation temporarily removes hairs from the surface while epilation removes hairs from their bulb. The management options vary in effectiveness, cost, and adverse effects such as pain, skin irritation, and distorted hair regrowth.

Depilation
Depilation methods include shaving, and chemical depilatories. Shaving does not affect the growth rate or diameter of the individual hairs. However, it can appear thicker and more coarse than before due to the hair having a blunt tip after shaving. While inexpensive, shaving can cause irritation and folliculitis. Chemical depilatories use sulfides, thioglycolates, and enzymatic depilatory agents which dissolve hairs by breaking the disulfide bonds that make up keratin. Chemical depilatories are painless and easy to use. Although sulfides can produce hydrogen sulfide which has an unpleasant odor and can irritate skin. Therefore, most chemical depilatories use thioglycolates which work slower in comparison to sulfides but are less odiferous and irritating.

Pharmacological Treatments
Eflornithine hydrochloride cream

Hirsutism vs Hypertrichosis
While both conditions relate to increased hair growth, hirsutism and hypertrichosis differ based on the location of hair growth and the dependence of the hormone androgen. "Hirsutism is the presence of excessive hair in androgen dependent and male pattern areas (especially in females). Hypertrichosis is excess hair growth, not limited to androgen-sensitive areas, and can be generalized or localized."

Signs and Symptoms
Prepubertal hypertrichosis is characterized by an excess of hair growth, seen during birth and progressing during childhood. In generalized hypertrichosis, excessive hair growth occurs all over the body, whereas in localized hypertrichosis, excessive hair growth only occurs in certain areas of the body. One example of localized, or circumscribed, prepubertal hypertrichosis is lumbosacral hypertrichosis, or faun tail nevus. The pattern of hair growth in generalized prepubertal hypertrichosis predominates the face, back, and limbs. Importantly, this is unique from excessive hair growth patterns in hirsutism.

Hypertrichosis itself is benign, but presents a cosmetic issue that may lead to psychosocial problems. As the child grows up, the hair growth may resume, increase, or decrease. However, overall growth patterns and progression may vary based on the classification of hypertrichosis, as well as its association with other disorders.

Diagnosis
There are many different forms of hypertrichosis which are distinguishable based on type of hair, age of onset, hair growth distribution, and location of hair growth.

Classification
Hypertrichosis diagnosis can be further specified by different classifications. These classifications can be distinguished from one another based on "type of hair, age of onset, distribution of hair, and location of hair growth."

Hair type

 * Lanugo: "fine, non-pigmented hair that covers the normal fetus. It is often several centimeters long. By the first few weeks of life, lanugo hair should be replaced by velds hair on the body and terminal hair on the scalp."
 * Vellus: "Lightly pigmented, fine, short hair, often referred to as "peach fuzz" that is found on the face, arms, stomach, and legs."
 * Terminal: "Coarse, thick hair that is found on the scalp, underarms, and pubic area."

Age of onset

 * Congenital: Present at the time of birth
 * Acquired: Not present at the time of birth but develops sometime after birth

Distribution

 * Generalized: Not limited to a certain area
 * Localized: Primarily affecting a certain area

In order to diagnose a patient with hypertrichosis, physicians must determine if the hair growth is true sexual hair or not. True sexual hair, compared to hair growth as a result of prepubertal hypertrichosis, "is dark, coarse, and terminal hair that is limited to androgen-dependent areas. Hypertrichosis refers to excess hair growth relative to persons of the same age, sex, and ethnicity but excludes androgen inducing hair growth."

Prepubertal hypertrichosis can be associated with other syndromes or diagnosed in isolation. Isolated congenital generalized hypertrichosis includes monogenic disorders: hypertrichosis lanuginosa congenita and hypertrichosis congenita terminalis. Syndromic congenital generalized hypertrichosis includes monogenic and chromosomal disorders. The monogenic disorders may be further distinguished by autosomal dominant, autosomal recessive, and X-linked disorders.

Generalized
Types of generalized isolated congenital hypertrichosis

Types of generalized syndrome-associated congenital hypertrichosis
 * Hypertrichosis lanuginosa congenita: lanugo hair growth all over the body, excluding the palms, soles, and mucous membranes, growing up to 3-5 cm.
 * Hypertrichosis congenita terminalis: terminal hair growth all over the body, excluding the palms, soles, and mucous membranes. It is often associated with gingival hyperplasia.

Monogenic


 * Autosomal dominant
 * Ambras syndrome (hypertrichosis universalis congenita): vellus hair growth all over the body, excluding the palms, soles, and mucous membranes.
 * Barbar-Say syndrome
 * Cantu syndrome
 * Coffin-Siris syndrome
 * Autosomal recessive
 * Leprechaunism
 * Berardinelli-Seip syndrome
 * Congenital erythropoietic porphyria (Gunther disease)
 * X-linked
 * Cornelia de Lange syndrome
 * Mucopolysaccharidoses type II

Chromosomal


 * Partial trisomy 3q

Localized
Types of localized congenital hypertrichosis 


 * Congenital melanocytic Nevus
 * Becker’s Nevus
 * Nevoid hypertrichosis

Potential sources of localized acquired hypertrichosis 


 * Secondary to herpes zoster
 * Contact dermatitis
 * Drugs
 * Gonococcal arthritis
 * Chronic osteomyelitis
 * Peripheral neuropathy
 * Burns, insect bite
 * Wart
 * Vaccination: in 2020, a case study reported that a Caucasian child developed two patches of hypertrichosis at the sites of vaccine injection for Diphtheria-Tetanus-acellular Pertussis-poliovirus (DTPa-IPV) and chicken pox . After the vaccines were given, the child had developed erythema, swelling, and itch at the two sites, and the hypertrichosis was reported 6 months later.
 * Cast application: several case studies have reported hypertrichosis in children after the application of casts. One study done in 2012 identified a significant number of cases of hypertrichosis in a group of 117 patients, ages ranging from 3 to 91 years old.

Etiology
While the cause of hypertrichosis is largely unknown for most cases, there have been some known factors that may cause an individual to have hypertrichosis.