Hair loss/excess Flashcards
What are the 3 different types of hair in humans ?
- Lanugo : fine long hairs covering the foetus. Shed about 1 month before birth
- Vellus : fine, short hair covering much of body surface. Replaces lanugo hairs before birth
- Terminal : long, coarse hairs eg scalp & pubic area. Growth influenced by androgen levels
What are the 4 phases of hair growth ?
- Anagen: actively growing hair, can last upto 6 years, 85-90% in this phase
- Catagen: in-between phase of 2–3 weeks when growth stops and the follicle shrinks
- Telogen: resting phase for 1–4 months
- Exogen: release of dead hair
Loss of how much scalp hair per day is normal ?
50-150
List the causes of generalised hair loss
- Telogen effluvium (excessive shedding) – occurs 2-6months after an event eg severe illness, childbirth, stress
- Endocrine – eg thyroid disease
- Drugs - contraceptives, anticoagulants, anti-convulsants
- Dietary deficiency: iron / zinc / vitamin D
- Diffuse alopecia areata
- Malnutrition
- Androgenetic alopecia
What are the 2 categories of localised hair loss ?
Scarring & non-scarring
List the causes of localised non-scarring hair loss
- Alopecia areata
- Androgenetic
- Trichotillomania
- Traction alopecia
- Tinea capitis
List the scarring causes of localised hair loss
- Burns / trauma
- CDLE
- Lichen planus
- Frontal fibrosing alopeci
What investigations may be done in someone presenting with hair loss ?
- Skin scrapings and hair pluckings
- Woods lamp examination
- Dermoscopy
- Scalp biopsy +/- DIF (direct immunofluorescence)
- Blood tests - FBC, TFTs, Iron / zinc levels, Hormone profile
What is alopecia areata?
- A chronic, inflammatory condition affecting the hair follicles which leads to sudden onset of non-scarring alopecia (hair loss).
- The result is localised one or more round bald patches appear suddenly, most often on the scalp.
What are the clinical features of alopecia areata ?
- Hair loss typically affects any hair-bearing area esp scalp or facial hair and is usually patchy and of sudden onset.
- Patches are round, well-circumscribed and smooth. Patches may coalesce into larger areas of alopecia. More rarely, hair loss may be diffuse.
- In the patches skin is normal-coloured or slightly red without scarring (the follicular openings are still present).
- Exclamation mark hairs (short broken hairs which taper proximally) may be seen at the edge or hair loss
- Nail changes include pitting, onycholysis, splitting, longitudinal ridging, red lanula, koilonychia, and leukonychia may occur.
When exammining the patches of hair loss in someone with alopecia areata what is seen ?
- Yellow / black dots
- Broken hair
- Tapering hair - “exclamation mark hair”
What is the treatment of aleopcia areata ?
Tx options include:
No treatment - hair will regrow in 50% by 1 year & 80-90% eventually
- If treatment wanted then 1st line = Try a potent or very potent TCS (do not use for facial areas)
- 2nd line = refer to dermatology, options include topical/systemic steroids, PUVA , DCP, Dithranol
Also should be informed on options of wigs & cosmetic camoflage
What is Trichotillomania?
- A disorder characterised by an irresistible urge to remove or pull one’s own hair, which results in alopecia (hair loss).
- It may develop as a coping mechanism triggered by stress or anxiety
Who does a disorder trichotillomania more commonly affect?
- People with OCD
- Commonly associated with other body-focused repetitive behaviours, such as nail biting (onychophagia), skin picking, acne excorié, lip biting and cheek chewing.
What are the clinical features of trichotillomania ?
- Most commonly affects the scalp
- Hair loss patterns vary from mild thinning or unnoticeable areas of hair loss to completely bald areas.
- It may occur when the individual is engaged in other activities such as watching television, reading etc. Or deliberately associated with compulsive urges and anxiety that are alleviated by hair pulling.
- Examination of the scalp may reveal irregularly-shaped patches of alopecia.
- They may feel stubbly, with hairs of varying lengths.
- Children tend to pull on hairs that are easy to reach and are on the same side as their dominant hand. These are usually the frontotemporal areas (areas behind the forehead and ears) and the vertex (top of the head).
What is the likely cause of this persons hair loss?
Trichotillomania - due to location etc
What is shown in this pic ?
Tinea capatis
What are the skin features of SLE ?
- malar (butterfly) rash: spares nasolabial folds
- discoid rash: scaly, erythematous, well demarcated rash in sun-exposed areas. Lesions may progress to become pigmented and hyperkeratotic before becoming atrophic
- photosensitivity
- Raynaud’s phenomenon
- livedo reticularis
- non-scarring alopecia
- dilated, tortuous nail-fold capillaries
What is shown in the pic?
dilated, tortuous nail-fold capillaries - sign of SLE
Discoid SLE is the most common form of cutaneous SLE (skin manifestation) what are the clinical features of it ?
- Most commonly affects scalp, ears, cheeks & nose
- Lesions are destructive, erythematous scaly plaques (on scalp these will cause alopecia/ bald patches)
- Scarring results in central loss of pigment (white patches) and skin atrophy (tissue loss)
What are the clinical features of male pattern androgenic alopecia ?
- Typically presents with bitemporal recession of the hairline & thinning of the crown (vertex) & frontal parietal areas
- Small proportion (10%) present with female pattern androgenic alopecia
What are the clinical features of female pattern androgenic alopecia ?
Typically presents with thinning in density of hair at the crown & frontal scalop, & widening of central parting with retention of frontal hairline
What is hirtuism ?
- It is a male pattern of secondary or post-pubertal hair growth occurring in women. It arises in the moustache and beard areas.
- Hirsute women may also develop thicker, longer hair than is usual on their limbs and trunk.
What are the clinical features of hypertrichosis ?
Excess hair growth may be localised to a particular area or generalised and covering all hair-bearing areas of the body.
