Short anagen hair syndrome.

Short anagen syndrome (SAS) is a condition in which hair does not grow long. It usually perceived by parents in children around 2-4 years of age. It is a benign disease of the hair cycle. The condition is relevant from the standpoint of differential diagnosis with loose anagen syndrome. We report a case of SAS in a Hispanic 3-year-old girl.

INTRODUCTION

Short anagen syndrome (SAS) is a recently recognized congenital disease clinically characterized by persistently short fine hair since birth, due to a decreased duration of the anagen phase.[123] The common complaint is that the hair does not grow long[234] and that it has never been cut.[45] Telogen effluvium is also a common complaint. Only a few cases have been published in the literature, mainly in Caucasian blond-haired girls.[25] Although some authors claim that short anagen is rare,[12] others believe that it is just under-recognized.[4]

We here present a case of SAS in a Hispanic, dark-haired girl.

CASE REPORT

A healthy Hispanic 3-year-old girl presented with a history of short hair since birth. The mother reported that there was excessive shedding and poor hair growth, and that the girl had never needed a haircut. Family history was negative for hair loss or hair diseases. Aggravating factors were denied and the past medical history was uneventful. Upon examination the patient was well- developed and did not present any abnormality except for short, dark, and thin hair [Figures 1 and 2]. The pull test was positive. Body hair was normal, as was the rest of the physical examination.

Figure 1

Note the short length hair in a 3-year-old child

Figure 2

Telogen hair with tipped point

Dermoscopy of pulled hairs showed 4.7 cm long telogen hairs with tipped points, which indicates that the hair had never been cut. A diagnosis of SAS was established through clinical and dermoscopic parameters.

DISCUSSION

Short anagen hair syndrome, as the name indicates, is a condition where the anagen phase is shortened[23456] and subsequently there is an increase in the number of telogen hairs.[35] The disease is congenital and is thought to be sporadic,[4] even though familial cases have been reported which may suggest an autosomal dominant inheritance.[3]

Clinically, although the hair shaft is normal without signs of breakage[134] the patients are not able to grow long hair and present with increased shedding.[234567]

The condition is usually benign,[34] nevertheless associations with tricho-dental syndrome,[6] synchronized pattern of scalp hair growth,[8] and micronychia[1] have been reported.

The characteristic clinical image and the finding of short (less than 6 cm long) telogen hairs with a tipped point at the pull test or trichogram makes the diagnosis.[45]

The main differential diagnosis has to be made with loose anagen syndrome, which also presents with short hair, but the hair is shed during anagen.[45]

Treatment is not necessary as this condition tends to improve after puberty,[34] however improvement with minoxidil and cyclosporine has been reported.[1]

For the exception of a case reported in an African-American patient,[5] three others in Caucasians with dark brown hair,[678] and one in an Asian patient[1] most cases have occurred in Caucasians with fine blond hair.[234] To our knowledge, based on a search of PubMed, (LILACS) Latin American and Caribbean Health Sciences Literature, and Google Scholar from 1999 to the present, using the terms “short anagen” and “SAS” as key words, this is the first case published in a Hispanic dark-haired girl in the English medical literature.