Dermatology Flashcards
What is pompholyx? What factors are thought to precipitate it?
. 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
What is hyperkeratotic palmar eczema? Which individuals does it most commonly present in?
. Fissured eczema on palms
. More common in middle aged people, especially those working with their hands a lot
How does seborrheic (cradle cap) eczema present? Which individuals does it most commonly affect and how is it managed?
. Red scaly dry/crusty scalp
. Newborns/infants
. Treat with antifungal shampoo
What is Asteatotic eczema caused by? In which individuals is it most common?
. Decreased lipids in skin leads to drying and cracking
. Most common in the elderly
What does lichenified mean?
Skin becomes thickened and leathery
Which common bacterial infection is often associated with eczema?
Impetigo (staphylococcal skin infection, very contagious)
How can scratching be managed in eczema patients at night?
Can give oral sedative e.g. chlorphenamine to help get to sleep
When would you start an eczema patient on steroids?
If emollients have been ineffective
What concentration of hydrocortisone is used? How is it used?
. 1% applied thinly to skin
. Used for short bursts of aggressive treatment
Which areas of the body should be avoided when applying hydrocortisone? Why is this?
. Face, and anogenital region
. These areas absorb much more than other parts of the skin
. Could lead to telangiectasia (prominent and dilated blood vessels)
If hydrocortisone isn’t effective, what might be the next step in treatment of atopic eczema?
. Use a more powerful steroid cream
. E.g. HC butyrate, Betnovate, Dermovate
What is the main issue with using more powerful steroid creams?
. Associated with side effects
. E.g. thinning of skin, secondary infection, telangiectasia, acne, depigmentation, pituitary-adrenal axis suppression, Cushing’s
What is the main concern with using oral steroids? How is this monitored?
Oral steroids can affect glucose control and interfere with growth, therefore should measure height regularly
When might ciclosporin and tacrolimus be used to treat eczema? What do they do and why are they sometimes preferred?
. 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
How is infected eczema (e.g. impetigo or eczema herpeticum) managed?
. Antiseptics, antibacterial (topical or oral), topical antifungals
. If eczema becomes infected with herpes would need emergency i.v. antivirals
What is contact dermatitis precipitated by? Give one predisposing factor and describe how it’s treated.
. Irritant reaction to chemicals (e.g. nickel, detergents, cosmetics)
. Predisposed by atopic dermatitis
. Treated with emollients, barrier creams, topical or oral steroids, antihistamines
What is napkin dermatitis?
Nappy rash (type of contact dermatitis) involving irritation to ammonia or infection
What is the difference between napkin dermatitis brought on by irritation to ammonia and napkin rash brought on by infection?
. 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
How is nappy rash caused by irritation treated? How about nappy rash involving infection?
. Irritation- improve hygiene, emollients/barrier creams,
. infection- antifungal (e.g. clotrimazole)
Give an example of an antifungal agent
Clotrimazole
What is the underlying mechanism for psoriasis? Which type is most common?
. Accelerated epidermal transit (excess epidermal cells produced) –> thick silvery scales
. Plaque psoriasis most common
Name 7 treatments for psoriasis
. 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)
Which treatment is considered first line for psoriasis? How does it work? What precautions must be taken when prescribing it?
. 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
How to oral retinoids work? Give an example of one. What is the main worry about using oral or topical retinoids?
. 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
Give an example of a cytotoxic agent sometimes used to treat psoriasis? How is it administered? What other uses does this agent have?
. Methotrexate, taken orally/i.v. once a week
. Also used to manage RA and used in chemotherapy for cancer treatment
How do infliximab and etanercept work to treat psoriasis?
Inactive TNF-α to reduce inflammatory/allergic response
How do ciclosporins work to treat psoriasis?
Immunosuppressants, quell allergic/inflammatory response
What type of infection are ringworm and athletes foot?
Fungal infections
What is candidiasis?
. Thrush (angry inflammation involving skin folds, intertrigo, Candida fungus)
. Fungal yeast infection, oral or vaginal most common
What is intertrigo?
Inflammation caused by skin-to-skin friction, commonly in groin, under breasts etc.
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?
. 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
