Alopecia, or hair loss, in children usually falls into one of three categories of causation.
Traumatic alopecia falls into two categories:
- Trichotillomania is compulsive hair pulling, often associated with the child eating the hair (which can cause a hair ball in the stomach, or bezoar).
- Traction alopecia - hair loss from too-tight hair styles or chemical damage to the hair.
Aplasia cutis congenita (a localized, congenital failure of the scalp to form) is characterized by small scalp erosions or flat, scarlike areas encircled by long, dark hair (the "hair collar" sign). These may be mistaken for the spot where the scalp lead of the fetal monitor was placed. There could be an underlying skull or brain defect; a CT scan may be ordered.
Androgenic alopecia typically appears in the teen years. There is a pattern of thinning over the crown with sparing of the frontal hairline. Blood hormone levels are checked to look for this condition; it is treated with testosterone blocking medication (spironolactone) or in girls, birth control pills. Rogaine may sometimes be beneficial.
Cosmetic damage from dyes, permanents, straighteners, or heat.
Loose anagen hair is an innate condition of some persons to have fine, easily dislodged hair. It is easily and painlessly plucked from the scalp due to poor root formation. It improves with age, and is treated by careful hair care with gentle combing, detanglers and conditioners.
Metabolic disease, chiefly thyroid disease
Dietary deficiency (rare in the US, possibly associated with intentional dietary practices
Nevus sebaceous (of Jadassohn)
- iron deficiency
- protein deficiency
Telogen effluvium is the hair loss that follows a shock to the body such as
It occurs about 2-3 months after the inciting event. It is a diffuse shedding of hair, which can come out in handfuls. This condition slowly disappears over about a six month period.
- severe illness
- high fever
- rapid and severe weight loss
Babies who spend a lot of time on their backs in the first few months may develop friction hair loss simply from rubbing the back of the head on the sheet. Also, babies typically lose the hair present at birth in the first months of life; this "baby hair" is replaced by their permanent adult-type hair.