Losing Your Crown

Common Hair Loss - Aetiology and Treatment Options

- Dr Eileen Tan, Dermatologist

Hair loss affects both the young and old. There are myriad potential etiologic factors that can culminate in clinical hair loss or alopecia, including endocrine abnormalities, genetic predisposition, systemic illness, drugs, psychological abnormalities, diet, trauma, infections, autoimmunity, and structural hair defects. Because of the multiplicity of factors, evaluation of a patient by history, physical examination and laboratory work-up must be thorough.

ANDROGENETIC ALOPECIA

Androgenetic alopecia (male/female pattern hair loss) is the most common cause of hair loss worldwide. A genetic predisposition is usually present. The hairs progressively miniaturise under the influence of dihydrotestosterone. Gradual patterned hair loss is the classical clinical presentation. There exist accepted classifications of androgenetic alopecia. The Norwood-Hamilton classification arbitrarily divides the severity of hair loss into seven stages. Women typically present with diffuse hair thinning, where there is diffuse hair thinning on the central portion of the scalp with a progressive increase in parting width.

TELOGEN EFFLUVIUM

Telogen effluvium occurs when a large amount of hair enters into telogen phase prematurely and sheds in 2-4 months after the offending insult. The list of causative triggers is extensive, including high fever, pregnancy, medications, malnutrition, severe infections, endocrine diseases, etc. Common causative medications include retinoid, anticoagulant, anticonvulsant, beta blocker, etc. A sudden onset of diffuse hair shedding is the most common clinical presentation. Patients often notice clumps of hair shedding when shampooing or hair brushing. History and physical examination are crucial to indicate the underlying aetiology. Treatment of telogen effluvium is usually self-limiting and involves eliminating the underlying cause.

ALOPECIA AREATA