Ch 3.4 - Dandruff & Psoriasis Flashcards
Dandruff a chronic relapsing condition of the scalp. How many people does it affect and in what age group?
Appears during puberty and peaks in adulthood.
1 in 2 people between the ages 20-30
4 in 10 people between the ages 30 -40
What usually causes dandruff?
Yeast - Malassezia furfur
What are the symptoms/appearance of dandruff?
Greyish-whit flakes or scales
Itchy scalp
Cell turnover is at twice the rate of those without the condition.
What is the differential diagnosis of severe dandruff? How to tell apart?
Psoriasis.
Severe seborrhoeic dermatitis - scales are yellowish and greasy looking, some inflammation with reddening & crusting of affected skin.
Psoriasis - silvery-white scales and associated with red patchy plaques and inflammation.
What are the aggravating factors of dandruff? (2)
- Hair dyes and perms can irritate the scalp
2. Inadequate rinsing after shampooing - irritation & itching.
When to refer - dandruff? (3)
- Suspected psoriasis
- Signs of infection
- Unresponsive to appropriate treatment
How long should dandruff treatments be left on for best effect?
How long does it take to see improvement overall?
5 mins
12 weeks
What is the aim of dandruff treatment and what is used?
To reduce the level of Malassezia furfur
- Ketoconazole (most effective)
- Selenium sulphide
- Zinc Pyrithione
- Coal tar (least effective)
How should ketoconazole 2% shampoo be used?
twice a week for 2-4 weeks - afterwhich should be reduced to weekly or fortnightly to prevent recurrence
Does ketoconazole shampoo cause side effects ?
No, it is not absorbed through the scalp
But - occasional allergic reactions
How does Selenium sulphide 2.5% work? What classification is this product? GSL? P?
Effective by reducing the cell turnover (cytostatic effect)
Any shampoo containing this ingredient is P
How should Selenium Sulphide be used?
Twice weekly for 2 weeks then once weekly for next 2 weeks - then PRN
What counselling points would you advise patient on the use of Selenium Sulphide?
HAir and scalp should be thoroughly rinsed as it can cause discolouration of blonde, grey or dyed hair.
Freq. use = scalp greasy, exacerbate it
Should not be used 48 hours before or after colouring or dying hair
Should not be applied to broken or inflamed skin
Shampoos containing zinc pyrithione are GSL. How do they work? How should they be used?
Cytostatic effect
twice weekly for the first 2 weeks then once weekly as required.
What are the cautions with coal tar?
Skin sensitisation and is a photosensitiser
What are some practical points for the treatment of dandruff?
- will not cure permanently - so need to use on less frequent basis to prevent dandruff coming back
- treating scalp not hair. gently massage scalp with product and let it for 5 mins
- Can use normal shampoo in-between uses. 3 times a week recommended
- Gel, mousse and hairspray can still be used - will not affect treatment
What are the two main hair loss types?
- Diffuse hair loss
2. Alopecia areata
What are the causes of diffuse hair loss?
- Alopecia androgenetica (common baldness) - most common
- Telogen effluvium
- Hypothyroidism
- Severe iron deficiency
- Protein deficiency
What medications can cause hair loss?
- Cytotoxic drugs
- Anticoagulants (coumarins)
- Lipid-lowering agents (Clofibrate)
- Vitamin A in overdose
Other such as:
Allopurinol, beta-blockers, bromocriptine, carbamazepine, colchinine, lithium & sodium valproate
When to refer- hair loss? (5)
- Alopecia areata
- Suspected drug induced hair loss
- Suspected hypothyroidism
4 Menstrual disorder - Suspected anaemia
How long will treatment with minoxidil show effect?
up to 4 months
What is the only licensed treatment for hair loss? and what strengths is it available?
Minoxidil 2% and 5%
lotion with the drug dissolved in an aqueous
alcohol solution. Propylene glycol is included to enhance absorption.
How should minoxidil be applied?
twice daily to dry scalp and lightly massaged into affected area.
Lotion should be left to dry naturally.
The hair should not be washed for at least 1 hour after using the lotion
In what situations should minoxidal NOT be used?
Alopecia areata
or
Hair loss related to pregnancy
