Hair Loss Flashcards
Which is the only form of hair loss that can be self-treated?
androgenetic alopecia
Which genders are affected by androgenetic alopecia?
Male and female
Is androgenetic alopecia scarring or non-scarring?
Non-scarring
What stages do hair growth occur?
anagen, catagen, telogen
How long do each of the hair growth phases last?
- anagen: 2-6y (determine hair length)
- catagen: 2-3w (no hair growth)
- telogen: 3m (after that, fully matured hair will be shed from hair follicle)
Main androgen involved in androgenetic alopecia?
dihydrotestosterone (DHT) (active metabolite of testosterone)
How is DHT formed?
Testosterone converted to DHT by enzyme 5-alpha-reductase
How does DHT cause hair loss?
DHT binds to androgen receptors on scalp & shortens anagen phase -> hair shafts become shorter & thinner (follicular miniaturisation) -> lower hair coverage over scalp
Which regions does hair loss usually occur in men and women?
Men: temporal, mid-frontal, vertex regions
Women: frontal, vertex
Treatment options for androgenetic alopecia? (and forensic classification)
- topical minoxidil (GSL)
- PO finasteride 1mg (POM) for men
What strength of minoxidil is used in men and women?
Men: usually 5%
Women: 2%, 3%, (5%)
Risk factors for hair loss?
- family history
- hormonal changes e.g. PCOS
- stress, childbirth, illness
MOA of minoxidil?
- increase cutaneous blood flow to hair follicles
- promote & maintain vascularisation of hair follicles
- transform resting hair follicles (telogen) to active hair follicles (anlagen) & prolong anlagen phase
What may happen in the first 2-8w of using TOP minoxidil?
Temporary increase in hair shedding
How long until effect is seen from using minoxidil 2% and 5%?
2%: 4m
5%: 2m
What happens if minoxidil treatment is stopped?
Hair density will return to pre-treatment levels in 3-4m
When to refer to dr if tx is not working?
- for 2%: 8m in women, 12m in men
- for 5%: 4-6m in both men & women
Can pregnant & breastfeeding mothers use TOP minoxidil as self-treatment?
No (safety & efficacy not established)
Can <18y or >65y, or those without family history of hair loss use TOP minoxidil as self-treatment?
No
Counselling points for minoxidil? (7)
- apply when hair & scalp are clean and dry
- can apply regardless if hair is shampooed & washed
- if hair is washed, use hairdryer with cool setting to dry hair after washing before applying
- massage 1mL into affected area BD (morning and night)
- wash & dry hands after application
- do NOT double dose for missed dose
- allow 2-4h for drug to penetrate scalp, avoid activities that may dilute or wash away meds
How many hours before sleep do you have to apply minoxidil and why?
2-4h before sleep to avoid staining of clothing & bed linen if not fully dried
Can you use a hair dryer after applying minoxidil? Why?
No, will reduce effectiveness of drug and preparations may contain alcohol (flammable)
Can you use minoxidil with permanent hair colouring or hair relaxer? How about hair grooming or styling products?
Cannot use minoxidil for 24h before or after application of permanent hair colouring or hair relaxer
Can use hair grooming or styling products after minoxidil has dried (will not affect effectiveness of minoxidil)
Minoxidil SE?
- local: redness, itch, dryness, scaling
- excessive hair growth outside application area
- systemic: weight gain, edema, tachycardia, hypotension
