Dermatology

Question 1

What is pompholyx? What factors are thought to precipitate it?

Answer 1

. Type of eczema where you get vesicles (itchy watery blisters), most commonly on sides of fingers, palms, soles of feet
. Exact cause unknown, but associated with stress, contact with certain metals (e.g. nickel), heat, can co-exist with atopic eczema or fungal infections

Question 2

What is hyperkeratotic palmar eczema? Which individuals does it most commonly present in?

Answer 2

. Fissured eczema on palms

. More common in middle aged people, especially those working with their hands a lot

Question 3

How does seborrheic (cradle cap) eczema present? Which individuals does it most commonly affect and how is it managed?

Answer 3

. Red scaly dry/crusty scalp
. Newborns/infants
. Treat with antifungal shampoo

Question 4

What is Asteatotic eczema caused by? In which individuals is it most common?

Answer 4

. Decreased lipids in skin leads to drying and cracking

. Most common in the elderly

Question 5

What does lichenified mean?

Answer 5

Skin becomes thickened and leathery

Question 6

Which common bacterial infection is often associated with eczema?

Answer 6

Impetigo (staphylococcal skin infection, very contagious)

Question 7

How can scratching be managed in eczema patients at night?

Answer 7

Can give oral sedative e.g. chlorphenamine to help get to sleep

Question 8

When would you start an eczema patient on steroids?

Answer 8

If emollients have been ineffective

Question 9

What concentration of hydrocortisone is used? How is it used?

Answer 9

. 1% applied thinly to skin

. Used for short bursts of aggressive treatment

Question 10

Which areas of the body should be avoided when applying hydrocortisone? Why is this?

Answer 10

. Face, and anogenital region
. These areas absorb much more than other parts of the skin
. Could lead to telangiectasia (prominent and dilated blood vessels)

Question 11

If hydrocortisone isn’t effective, what might be the next step in treatment of atopic eczema?

Answer 11

. Use a more powerful steroid cream

. E.g. HC butyrate, Betnovate, Dermovate

Question 12

What is the main issue with using more powerful steroid creams?

Answer 12

. Associated with side effects
. E.g. thinning of skin, secondary infection, telangiectasia, acne, depigmentation, pituitary-adrenal axis suppression, Cushing’s

Question 13

What is the main concern with using oral steroids? How is this monitored?

Answer 13

Oral steroids can affect glucose control and interfere with growth, therefore should measure height regularly

Question 14

When might ciclosporin and tacrolimus be used to treat eczema? What do they do and why are they sometimes preferred?

Answer 14

. Sometimes used for children with atopic eczema who are unresponsive to topical or oral steroids
. Ciclosporin and tacrolimus are immunosuppressants, so suppress the allergic inflammatory response in eczema
. Steroid-sparing treatment

Question 15

How is infected eczema (e.g. impetigo or eczema herpeticum) managed?

Answer 15

. Antiseptics, antibacterial (topical or oral), topical antifungals
. If eczema becomes infected with herpes would need emergency i.v. antivirals

Question 16

What is contact dermatitis precipitated by? Give one predisposing factor and describe how it’s treated.

Answer 16

. Irritant reaction to chemicals (e.g. nickel, detergents, cosmetics)
. Predisposed by atopic dermatitis
. Treated with emollients, barrier creams, topical or oral steroids, antihistamines

Question 17

What is napkin dermatitis?

Answer 17

Nappy rash (type of contact dermatitis) involving irritation to ammonia or infection

Question 18

What is the difference between napkin dermatitis brought on by irritation to ammonia and napkin rash brought on by infection?

Answer 18

. Irritation doesn’t affect skin folds (because inside of folds not in contact with ammonia form urine)
. Infection affects skin folds because widespread, often fungal

Question 19

How is nappy rash caused by irritation treated? How about nappy rash involving infection?

Answer 19

. Irritation- improve hygiene, emollients/barrier creams,

. infection- antifungal (e.g. clotrimazole)

Question 20

Give an example of an antifungal agent

Answer 20

Clotrimazole

Question 21

What is the underlying mechanism for psoriasis? Which type is most common?

Answer 21

. Accelerated epidermal transit (excess epidermal cells produced) –> thick silvery scales
. Plaque psoriasis most common

Question 22

Name 7 treatments for psoriasis

Answer 22

. Topical emollients
. Topical steroids
. Dithranol (antiproliferative)
. Tar (keratolytic, breaks down excess keratin)

. PUVA (bathe in psoralen then exposed to UVA to slow turnover of cells)
. Retinoids (vitamin A analogues, bind to nuclear retinoic acid receptors to slow transcription)
. Cytotoxics (e.g. methotrexate, slows cell turnover)
. Ciclosporin (immunosuppressant)
. Infliximab/etanercept (inactivate TNF-α)

Question 23

Which treatment is considered first line for psoriasis? How does it work? What precautions must be taken when prescribing it?

Answer 23

. Dithranol (antiproliferative)
. Inhibits DNA synthesis to slow down the rapid turnover of cells which underlies psoriasis
. Can cause hypersensitivity in some people, so do patch test before prescribing
. Can also stain clothes, so warn patient

Question 24

How to oral retinoids work? Give an example of one. What is the main worry about using oral or topical retinoids?

Answer 24

. Vitamin A analogues that bind tot nuclear retinoic acid receptors to slow transcription, thus slowing production of epidermal cells
. Acitretin is the main one used
. Retinoids are highly teratogenic, so must do pregnancy test before and during treatment, use effective contraception, and ensure no pregnancy until 3 years after stopping retinoid/acitretin treatment

Question 25

Give an example of a cytotoxic agent sometimes used to treat psoriasis? How is it administered? What other uses does this agent have?

Answer 25

. Methotrexate, taken orally/i.v. once a week

. Also used to manage RA and used in chemotherapy for cancer treatment

Question 26

How do infliximab and etanercept work to treat psoriasis?

Answer 26

Inactive TNF-α to reduce inflammatory/allergic response

Question 27

How do ciclosporins work to treat psoriasis?

Answer 27

Immunosuppressants, quell allergic/inflammatory response

Question 28

What type of infection are ringworm and athletes foot?

Answer 28

Fungal infections

Question 29

What is candidiasis?

Answer 29

. Thrush (angry inflammation involving skin folds, intertrigo, Candida fungus)
. Fungal yeast infection, oral or vaginal most common

Question 30

What is intertrigo?

Answer 30

Inflammation caused by skin-to-skin friction, commonly in groin, under breasts etc.

Question 31

Which drugs are used to treat fungal infections? Which has longer effect? If topical versions of these drugs don’t work, what is the next step?

Answer 31

. Imidazole (e.g. clotrimazole) or terbinafine
. Terbinafine has better penetration into the skin so has longer lasting effects
. Move onto oral tablets if topical creams don’t work