Hair loss

Probability diagnosis

Androgenetic alopecia (male pattern baldness)

Alopecia areata (diffuse type)

Telogen effluvian (incl. postpartum)

Anagen effluvian (esp. cytotoxic therapy)

Seborrhoeic dermatitis

Serious disorders not to be missed

Infection:

• tinea capitis

• bacterial folliculitis

• secondary syphilis

• post-febrile state

Cancer:

• treatment for cancer

Other:

• systemic disease (e.g. lupus)

Pitfalls (often missed)

Rarities:

Heavy metal poisoning

Nutritional:

• severe dieting

• malnutrition

• zinc/iron deficiency

Masquerades checklist

Drugs (cytotoxics, anticoagulants, anti-epileptics, amphetamines, anti-thyroid agents, various hormones, cessation OCP)

Thyroid/other endocrine (hypothyroidism)

Is the patient trying to tell me something?

Emotional stress → telogen effluvium. Trichotillomania.

Key history

• Onset, duration, quantity and rate of loss

• Localised or generalised loss

• Characteristics of hair (e.g. scales, white bulbs)

• Associated symptoms (e.g. pruritus, scaling, pustules)

• Systems review including fever, acute illness, surgery, stressors

• Endocrine features

• Past history including skin disorders, cancer, thyroid disorders

• Family history of hair loss

• Drug history

Key examination

• General review with emphasis on endocrine system and examination of scalp

• Look for exclamation mark hair, ‘white bulb’ hair, state of bald patch (clean, scaly, scarred or inflamed) and the unusual pattern of trichotillomania

Key investigations

Consider:

• FBE/ESR

• pituitary hormones (FSH/LH/prolactin/TSH)

• hair pull test

• trichogram

• scalp biopsy

• skin scrapings and hair sample for fungal microsurgery and culture.

Diagnostic tips

• Androgenetic (male pattern and female pattern hair loss) is the most common type.

• Microscopic examination (light or electron) may be required for definitive diagnosis.

• For patchy loss consider alopecia areata and trichotillomania.

• Generalised loss: consider telogen effluvium, systemic disease and drugs.

• In telogen effluvium, the traumatic event has preceded the hair loss by about 2 months (peak loss at 4 months). ‘White bulbs’ are diagnostic.