Ch 3.4 - Dandruff & Psoriasis

Question 1

Dandruff a chronic relapsing condition of the scalp. How many people does it affect and in what age group?

Answer 1

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

Question 2

What usually causes dandruff?

Answer 2

Yeast - Malassezia furfur

Question 3

What are the symptoms/appearance of dandruff?

Answer 3

Greyish-whit flakes or scales
Itchy scalp

Cell turnover is at twice the rate of those without the condition.

Question 4

What is the differential diagnosis of severe dandruff? How to tell apart?

Answer 4

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.

Question 5

What are the aggravating factors of dandruff? (2)

Answer 5

1. Hair dyes and perms can irritate the scalp

2. Inadequate rinsing after shampooing - irritation & itching.

Question 6

When to refer - dandruff? (3)

Answer 6

1. Suspected psoriasis
2. Signs of infection
3. Unresponsive to appropriate treatment

Question 7

How long should dandruff treatments be left on for best effect?

How long does it take to see improvement overall?

Answer 7

5 mins

12 weeks

Question 8

What is the aim of dandruff treatment and what is used?

Answer 8

To reduce the level of Malassezia furfur

1. Ketoconazole (most effective)
2. Selenium sulphide
3. Zinc Pyrithione
4. Coal tar (least effective)

Question 9

How should ketoconazole 2% shampoo be used?

Answer 9

twice a week for 2-4 weeks - afterwhich should be reduced to weekly or fortnightly to prevent recurrence

Question 10

Does ketoconazole shampoo cause side effects ?

Answer 10

No, it is not absorbed through the scalp

But - occasional allergic reactions

Question 11

How does Selenium sulphide 2.5% work? What classification is this product? GSL? P?

Answer 11

Effective by reducing the cell turnover (cytostatic effect)

Any shampoo containing this ingredient is P

Question 12

How should Selenium Sulphide be used?

Answer 12

Twice weekly for 2 weeks then once weekly for next 2 weeks - then PRN

Question 13

What counselling points would you advise patient on the use of Selenium Sulphide?

Answer 13

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

Question 14

Shampoos containing zinc pyrithione are GSL. How do they work? How should they be used?

Answer 14

Cytostatic effect

twice weekly for the first 2 weeks then once weekly as required.

Question 15

What are the cautions with coal tar?

Answer 15

Skin sensitisation and is a photosensitiser

Question 16

What are some practical points for the treatment of dandruff?

Answer 16

1. will not cure permanently - so need to use on less frequent basis to prevent dandruff coming back
2. treating scalp not hair. gently massage scalp with product and let it for 5 mins
3. Can use normal shampoo in-between uses. 3 times a week recommended
4. Gel, mousse and hairspray can still be used - will not affect treatment

Question 17

What are the two main hair loss types?

Answer 17

1. Diffuse hair loss

2. Alopecia areata

Question 18

What are the causes of diffuse hair loss?

Answer 18

1. Alopecia androgenetica (common baldness) - most common
2. Telogen effluvium
3. Hypothyroidism
4. Severe iron deficiency
5. Protein deficiency

Question 19

What medications can cause hair loss?

Answer 19

1. Cytotoxic drugs
2. Anticoagulants (coumarins)
3. Lipid-lowering agents (Clofibrate)
4. Vitamin A in overdose

Other such as:
Allopurinol, beta-blockers, bromocriptine, carbamazepine, colchinine, lithium & sodium valproate

Question 20

When to refer- hair loss? (5)

Answer 20

1. Alopecia areata
2. Suspected drug induced hair loss
3. Suspected hypothyroidism
   4 Menstrual disorder
4. Suspected anaemia

Question 21

How long will treatment with minoxidil show effect?

Answer 21

up to 4 months

Question 22

What is the only licensed treatment for hair loss? and what strengths is it available?

Answer 22

Minoxidil 2% and 5%
lotion with the drug dissolved in an aqueous
alcohol solution. Propylene glycol is included to enhance absorption.

Question 23

How should minoxidil be applied?

Answer 23

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

Question 24

In what situations should minoxidal NOT be used?

Answer 24

Alopecia areata
or
Hair loss related to pregnancy

Question 25

Which patients should be cautious/ talk to GP before using minoxidil?

Answer 25

Hypertension
Angina
Heart disease

Question 26

Describe the appearance of psoriasis

Answer 26

Raised, large, red, scaly patches/plaques on elbow or knee & scalp

Patches are symmetrical and sometimes present on the lower back area.

Question 27

Which drugs can aggravate psoriasis?

Answer 27

Lithium, beta-blockers and anti-malarials.

Question 28

What are the possible treatments for psoriasis?

Answer 28

1. Dithranol (0.1-2%) creams
2. Vitamin D derivatives -calcipotriol or tacalcitol (risk of hypocalcaemia if overused)
3. Topical steroids - careful of long term use and restricted for use on flexures or scalp

Question 29

What is second line treatment of psoriasis?

Answer 29

Second-line treatment may include phototherapy or systemic
therapy with methotrexate (long term use= liver damage), etretinate or ciclosporin (cyclosporin).

All of have serious side effects.