T. Papps1,2, S. Smithson2, L. Yip2, D. Orchard2
Hypotrichosis is uncommon condition, and although there is a lot known about it from a genetic perspective, there is little related clinical literature. This is the hallmark of the clinical challenge of hypotrichosis, with broad differentials, in addition to limited effective treatments and other considerations such as patient expectations.
Hypotrichosis can be categorised into hair fragility syndromes, anagen duration problems (loose and short anagen) and true hypotrichosis. There is normal or sparse hair at birth, with gradual hair loss during childhood observed, or tight/twisted/wooly hair, which progresses into sparse/no hair in adulthood. There are over 100 genetic mutations linked.
Hypotrichosis can be viewed as association with or without a syndrome, with syndromic associations including ichthyosis/immunodeficiency/premature ageing/juvenile macular/ectodermal dysplasias. Hypotrichosis without syndromic associations include ‘isolated hereditary hair loss disorders’/autosomal dominant/autosomal recessive.
This clinical and genetic heterogeneity of the disorder makes it a diagnostic challenge. A method of assessment and diagnostics in this cohort is proposed with firstly hair pull test, secondly hair microscopy, and thirdly assessment of other features, such as syndromes or ectodermal dysplasias. As a practical approach, abnormal teeth/nails/ sweating is likely attributed to ectodermal dysplasia, other systemic or developmental problems likely attributed to a syndrome, and if patient otherwise well consider an isolated hereditary hypotrichosis condition.
Following clinical assessment and diagnosis, one must consider possible treatment options depending on aetiology, for example novel considerations with vitamin D in ectodermal dysplasia, despite the limitations in available therapies.