Al-Refu, K., Hair Loss in Children, Etiologies, and Treatment in Hair and Scalp Disorders, 2017

Edited and translated by Prof. Dr. Murat Turkoglu

Hair loss in children is a common and important complaint in dermatology and pediatric clinics and can be considered a difficult problem in some cases. Early treatment is necessary as it affects the normal mental and physical development of children. Hair loss is worrying especially in the pediatric group, as it is associated with more important psychological consequences in this growing age group and has different patterns than those seen in adults. There are common and rare causes of this complaint.

To fully understand hair loss in children, it is necessary to understand normal hair growth. Generally, all hair follicles of the developing fetus are formed in the 22nd week of intrauterine life. At this stage, there are approximately one million hair follicles on the head. The hairs on the scalp grow approximately 0.3-0.4 mm per day. Random number of hairs at any given time will be in one of three stages of growth and loss: anagen, catagen, and telogen. Each phase has certain characteristics that determine the length of the hair. All three stages occur at the same time. While one hair strand may be in the anagen phase, the other may be in the telogen phase. Essentially, there are three basic hair groups depending on the size of the hair follicle.

(A) Lanugo hairs are long, pigmentless and very fine. As an embryo develops, hair follicles are formed and begin to produce this type of hair. This first wave of growth normally falls out at the end of about 8 months of pregnancy and is replaced by terminal or vellus hair ready for birth. Sometimes, however, babies are born with this lanugo hair (called "congenital hypertrichosis lanuginose").

(B) Vellus are short, fine, pigmentless hair. This type of hair is usually seen on the nose and cheeks.

(C) Terminal is long, coarse, pigmented, and often contains a medulla. During adolescence, many hair follicles around the genitals, armpits, beard and chest in men turn from vellus hair to terminal hair with the direction of hormones.

Common causes of hair loss in children are telogen effluvium, tinea capitis, bacterial infections, traction alopecia, trichotillomania, and alopecia areata. In addition to the previous one, there may be other less common causes of hair loss, such as thyroid disorders and diseases such as systemic lupus erythematosus, diabetes mellitus or iron deficiency anemia, malnutrition, structural abnormalities of the hair shaft that often result in easy breakage.

What Causes Hair Loss in Children?

Congenital Diseases

Jadassohn's nevus sebase

Jadassohn's nevus sebase (also known as sebaceous nevus) is a yellow-orange, waxy, hairless plaque that typically forms on the scalp. Such nevus are present at birth or in early childhood as a balding congenital plaque, but show a notable overgrowth during adolescence. 

Aplazi cutis konjenita

Aplasia cutis congenita (Congenital absence of skin "and" Congenital scars) is a heterogeneous group of diseases characterized by the absence of a localized or widespread part of the skin at birth. The defect may involve only the epidermis and upper dermis and may result in minimal alopecia, or extend into the deep dermis, subcutaneous tissue. 

Ectodermal dysplasia

Ectodermal dysplasias are defined as inherited conditions in which there are abnormalities in two or more ectodermal structures, such as hair, teeth, nails, or sweat gland function, as well as another abnormality in one tissue of ectodermal origin. It is not a single disease. It is a group of syndromes. Signs and symptoms are usually not evident in newborns and may not appear until infancy or childhood. Affected people have abnormal hair follicles (scalp and body hair may be thin, sparse and very light colored). Hair can grow very slowly or unevenly and may be extremely brittle, curly or even twisted. 

Hair shaft abnormalities

Hair shaft abnormalities are characterized by changes in color, density, length, and structure. Hair shaft changes are often caused by structural changes in the hair fibers and cuticles, which can lead to brittle and uncombed hair. Hair shaft abnormalities can result in dry and unshiny hair, coarse or uncombable hair, and brittle hair. Hair shaft diseases can occur as localized or general disorders.

Loose anagen hair syndrome

Loose anagen syndrome is a benign, self-limiting condition in which anagen hair is removed easily and painlessly and is mostly reported in childhood. It can be seen in the normal population and in alopecia areata. Hair is relatively thin and does not grow long. The hair is light in color and has low-caliber hair strands.  

Subsequent Diseases

There are five common types of hair loss in children: tinea capitis-associated alopecia, alopecia areata, traction alopecia, telogen effluvium, and trichotillomani /trichotillosis.

Tinea capitis

Tinea capitis (ringworm of the scalp) is one of the most common causes of hair loss. It is a disease caused by a superficial fungal infection of the scalp that tends to attack the hair follicles and follicles. Tinea capitis is the most common pediatric dermatophyte infection worldwide.

Alopesi areata

It is an autoimmune disease in which hair is shed from the scalp or other hairy areas of the body such as eyebrows and eyelashes. It often causes bald spots on the scalp, especially in the early stages. Rarely, the condition may spread to the entire scalp (alopecia totalis) or to the entire skin (alopecia universalis). This type of alopecia is a disease in which hair strands fall out, but hair follicles are protected. Typically, the patient first seeks a doctor with small bald patches. These patches can come in many shapes but are mostly round or oval. The disease may also go into remission for a period of time or be permanent. It is common in children.

Traction alopecia

Traction alopecia is a gradual hair loss caused mainly by frequent and chronic hair pulling, and this is usually caused by hair styling habits. It is also seen in people with long hair who use hairpins to keep their hair away from their face. There is a large variation in the clinical presentation pattern of traction alopecia. 

Telogen effluvium

This is not an uncommon cause of hair loss in children; It refers to the abnormality in the normal hair cycle that leads to excessive telogen hair loss. In telogen effluvium, many factors interrupt the normal life cycle of the hair and throw most or all of the hair into the telogen phase, after a few weeks, partial or complete baldness occurs. Similar to adult-type telogen effluvium, many different events, extreme high fever, previous severe illnesses, surgery under general anesthesia, severe prolonged emotional stress, serious injuries, and the use of certain prescription medications can cause telogen effluvium.

Trichotollimenia

Trichotollimenia is defined as a child or adolescent disease in which children compulsively pluck their hair and it is thought to be associated with obsessive-compulsive disorder. These children have visible hair loss and often need treatment by a child psychiatrist or child psychologist. Hair loss is uneven and is characterized by different lengths of hair. The patches are often seen next to the child's dominant hand.

Diagnosis and Treatment

In most cases of hair loss in children, a dermatologist can diagnose these conditions and prescribe appropriate treatment. However, some hair conditions do not have an effective treatment or the treatment is not 100% successful. Congenital and hereditary hypotrichosis and hair shaft abnormalities usually have no effective treatment.

Treatment for tinea capitis usually involves systemic antifungal therapy such as griseofulvin taken orally for 8 weeks. Tinea capitis is also treated with antifungal shampoo and the hair is washed the scalp 2-3 times a week. It is very important to continue using oral medication and shampoo for 8 weeks. Children with tinea capitis do not need to stay out of school if the treatment is used as directed, but they should be careful not to share objects that touch the head, such as hats and pillows. Most children are not contagious when using oral medication and shampoo.

Alopecia areata is an unpredictable disease, and even with a full recovery, it is possible for it to reappear throughout your child's life. Most kids' hair will return within a year, but regrowth is unpredictable and many lose their hair again. Treatment for alopecia areata depends on the severity of the involvement. If the disorder is mild and does not cause the patient too much trouble, it is a sensible option to wait for a spontaneous recovery. Treatment with zinc as an immunomodulator generally has no side effects and is therefore suitable for use in children.

Counseling and psychotropic drugs such as clomipramine or sertraline, N-acetyl cysteine, and behavior modification techniques (Habit reversal therapy) are effective treatment options in trichotillominea.

Traction alopecia is a reversible alopecia and its treatment is the cutting of uncomfortable hair. However, if the hair continues to be pulled for years, mechanical damage to the hair follicles may cause permanent hair loss. Assuming there is no intervening pathological process, in telogen effluvium, the loss is usually renewed in 6-12 months.