Practical guidelines for evaluation of loose anagen hair syndrome.
OBJECTIVE
To better categorize the epidemiologic profile, clinical features, and disease associations of loose anagen hair syndrome (LAHS) compared with other forms of childhood alopecia.


METHODS
Retrospective survey.


METHODS
Academic pediatric dermatology practice. Patients Three hundred seventy-four patients with alopecia referred from July 1, 1997, to June 31, 2007.


METHODS
Epidemiologic data for all forms of alopecia were ascertained, such as sex, age at onset, age at the time of evaluation, and clinical diagnosis. Patients with LAHS were further studied by the recording of family history, disease associations, hair-pull test or biopsy results, hair color, laboratory test result abnormalities, initial treatment, and involvement of eyelashes, eyebrows, and nails.


RESULTS
Approximately 10% of all children with alopecia had LAHS. The mean age (95% confidence interval) at onset differed between patients with LAHS (2.8 [1.2-4.3] years) vs patients without LAHS (7.1 [6.6-7.7] years) (P < .001), with 3 years being the most common age at onset for patients with LAHS. All but 1 of 37 patients with LAHS were female. The most common symptom reported was thin, sparse hair. Family histories were significant for LAHS (n = 1) and for alopecia areata (n = 3). In 32 of 33 patients, trichograms showed typical loose anagen hairs. Two children had underlying genetic syndromes. No associated laboratory test result abnormalities were noted among patients who underwent testing.


CONCLUSIONS
Loose anagen hair syndrome is a common nonscarring alopecia in young girls with a history of sparse or fine hair. Before ordering extensive blood testing in young girls with diffusely thin hair, it is important to perform a hair-pull test, as a trichogram can be instrumental in the confirmation of a diagnosis of LAHS.
Cantatore-Francis
Julie L
JL
Department of Dermatology, New York University School of Medicine, New York University Medical Center, New York, NY 10016, USA.
Orlow
Seth J
SJ
D017668:Age of Onset; D000505:Alopecia / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D017408:Guidelines as Topic; D006197:Hair / Q000002:abnormalities / Q000648:ultrastructure*; D006801:Humans; D015994:Incidence; D007223:Infant; D008854:Microscopy, Electron; D011336:Probability; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013577:Syndrome