Case 9

This 6-year-old girl presented with an area of decreased hair length in the middle of her scalp. It was a square-shaped area with hairs of various lengths but none greater than a few centimetres long, as shown in Image 9a. Her scalp underlying that area was normal with no pustules, scales, bald spots or tender areas. Her remaining hair reached below her collar line in length and appeared healthy. On further exam, her upper eyelashes looked ‘gone’. Under magnification, lashes that measured 1–2 mm in length were seen remaining at the orifice of each follicle. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig9a.jpg"/>

What is the diagnosis?

What are the key clinical features that assist you in making this diagnosis?

Can blood or skin biopsies support the diagnosis?

What is the treatment?

18This child suffers from trichotillomania. Trichotillomania is an impulse disorder characterized by the manual pulling, plucking, twirling or twisting of the hair causing breakage and shortening of the hair from the scalp and/or other sites. ¹ It can be done consciously or unconsciously. Most of these children deny they are pulling their hair either because they are defensive or because the action is done subconsciously. It is important to consider child abuse and abusive hair pulling as a cause of localized hair loss in children especially if a mechanical alopecia – trichotillomania or traction alopecia – is being considered. ²

The key clinical feature is that the hairs are of various lengths in the area but none are longer than a few centimetres. This is because there needs to be a given length of hair that the patients can physically grasp with their fingers or fingernails. Hair shorter than a few centimetres cannot be pulled or removed. In addition, the area involved is almost always irregular in shape (e.g. rectangular or star shaped) and usually on the side of the dominant hand (e.g. more on the right side of the scalp than the left). Careful examination is important as it may involve less visible areas of the scalp, as shown in Image 9b.

There are no blood tests, but a skin biopsy of the scalp can show fractured hairs within the hair shaft which is quite indicative. Also there are neither ‘exclamation point hairs’ nor ‘black dot hairs’ as seen in alopecia areata and tinea capitis, respectively. The scalp always has some hair and is never completely bald. There are no red pustules, scars or dyschromia.

Young children have a good prognosis. However, the prognosis is more guarded in older children, adolescents and adults. Sometimes just gently suggesting where the behaviour is coming from and offering some simple distracting actions to keep the hands busy may be of benefit. Behaviour modification and help from a trained psychiatric professional are often needed.

https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429170423/e1d751c1-a9c7-4bb9-9d59-53742c84031a/content/fig9b.jpg"/>