Derm stuff you forget

Question 1

Which surfaces do eczema and plaque psoriasis tend to effect?

Answer 1

Psoriasis - extensor surfaces
Eczema - flexor surfaces

Question 2

What things can exacerbate psoriasis?

Answer 2

Trauma
Drugs (BLANC - beta blockers, lithium, alcohol, NSAIDs, chloroquine)
Withdrawal of steroids
Strep infection (guttate type)

Question 3

Describe guttate psoriasis

Answer 3

2nd most common, seen more in kids.

Acute onset - small, tear-shaped papules on trunk and limps, slightly scaly and non-blanching. Papules -> plaques.

Often triggered by strep throat

Self-limiting over 3-4ms.

Question 4

Describe the management for psoriasis

Answer 4

Mild disease - emollients.

1st line - topical steroids OD for up to 4wks to settle flare.

2nd line - if no improvement, try stronger steroid, coal tar or short acting dithranol.

Options in 2o care - phototherapy, oral methotrexate, biologics.

Question 5

Name a mild, moderate, potent and very potent topical steroid

Answer 5

Mild - hydrocortisone
Moderate - Eumovate
Potent - Betnovate
Very potent - Dermovate

Question 6

Describe the management of eczema, referencing flares and maintenance

Answer 6

Flares treated with thicker emollients and topical steroids

Maintenance - emollients used as often as possible.

Question 7

Describe eczema herpeticum agent, demographic, Px and Tx

Answer 7

It is primary infection of eczema skin by HSV1 or 2

More common in children w/ atopic eczema.

Px w/ rapidly progressing painful rash with punched out lesions.

Needs hospital admission and IV aciclovir as life-threatening.

Question 8

What is an open and closed comedome?
What is a papule and pustule?

Answer 8

A comedone is a non-inflamed pilosebaceous unit.
- open = blackheads (oxidation of trapped material)
- closed = whiteheads (white due to thin covering layer of skin)

If comedones become inflamed they can become papules and pustules.
- papule is small, raised, red, bumps.
- pustules are similiar but contain pus.

Question 9

Describe mild, moderate, severe acne

Answer 9

• Mild - open and closed comedones without inflammatory lesions.
• Moderate - comedones with numerous papules and pustules.
• Severe - extensive inflammatory lesions and scarring.

Question 10

Describe the management of acne.

Answer 10

Mild/moderate - combination of 2 of topical retinoids (adapalene/tretinoin), topical benzoyl peroxide, topical clindamycin.

Moderate/severe - try OCP in women, or oral abx - doxycycline (max 3m).

2o care may try oral retinoids.

Question 11

Tx of acne rosacea

Answer 11

Predominant flushing - topical brimonidine (alpha agonist)

Mild/moderate - topical ivermectin 1st line (or topical metronidazole)

Moderate/severe - above + oral doxycycline.

NB ivermectin is an antiparasitic medication

Question 12

4 RF for all skin cancers

Answer 12

UV exposure (main one)
Fitzpatrick skin types 1-2 (fair skin)
Increasing age
Immune suppression

Question 13

How should BCC, keratocanthoma, SCC and MM be referred?

Answer 13

• BCC - malignant but can be referred routinely.
• Keratocanthoma - benign but needs urgent referral (2ww) as indistinguishable from SCC.
• Melanoma and SCC need urgent referral (2ww)

Question 14

Name to pre-malignant conditions for SCC

Answer 14

Actinic keratosis (most common precursor)
Bowen disease

Question 15

Describe SCC appearance

Answer 15

Irregular keratinous nodule (resembles a wart), frequently ulcerates,
Rapidly grows
May be painful, tender, itchy and made bleed.

Question 16

How is actinic keratosis treated?

Answer 16

Can remit spontaneously.
Encourage moisturises
Lesion specific treatment - Cryotherapy, keratolytic cream (5-flourouracil/Efudix)

Question 17

Describe BCC appearance

Answer 17

Slowly growing plaque/nodule. Rolled edges with central depression.
Skin is pink or pigmented (often shiny/pearly).
Telangiectasia on dermoscopy.

Question 18

What does Tinea mean?

Answer 18

Tinea is a group of fungal conditions of the skin. Caused by Trichophyton (dermatophytes)

Question 19

What are the types of Tinea and how do they present?

Answer 19

Generally, itchy rash which is erythematous, scaly, well-demarcated. Target lesion.

Tinea capitis - well-demarcted hair loss w/ itching and erythema.
Tinea pedis - athletes foot. White/red, flaky cracked, itchy patches between the toes.
Onychomycosis - thickened, discoloured nails.

Question 20

How do you treat tinea?

Answer 20

Creams like clotrimazole and miconazole.
Oral fluconazole generally 2nd line but 1st line for fungal nail and tinea capitis.

Question 21

Tinea/pityriasis versicolor cause, RF, appearance, Tx

Answer 21

Skin infection with yeasts/fungi.

More common in tropical environments, summer and adolescents.

Demarcated, scaly, oval hypo or hyperpigmented macules that form patches. Noticed when tanning. Slight itching.

Clinical diagnosis.

Tx w/ topical antifungal (ketoconazole)

Question 22

Pityriasis rosea cause, RF, appearance, Tx

Answer 22

Cause not understood, maybe HHV 6/7.

Most common in young adults.

Prodromal Sx of flu-like sx, rash starts with herald patch (pink/red scaly oval lesion usually on torso). Actual rash is small pink spots in christmas tree pattern. Slight itch, may be headache, lethargy.

No Tx as resolves within 3m without long term Cx. Not contagious.

Question 23

What is intertrigo?

Answer 23

a rash in the flexures due to high temp/sweat/friction.
Can be infective (usually asymmetric and unilateral) w/ thrush, tinea, impetigo or boils.
Can be inflammatory (symmetrical) w/ psoriasis, seborrhoeic dermatitis, etc.

Question 24

How does intertrigo present?

Answer 24

Overweight/obese or lymphoedema.

Skin is inflamed, red, uncomfortable, may be peeling, may be a foul odour.

Question 25

How do you treat intertrigo? (hint depends on cause)

Answer 25

Napkin dermaitis - zinc oxide paste.
Bacterial infection - topical abx (fusidic acid cream) or PO if required.
Fungal/yeasts - topical antifungals (clotrimazole)
Inflammatory - low potency topical steroids.

Question 26

Name a common cause of pruritus ani and how is it treated?

Answer 26

Threadworm - mebendazole

Question 27

Describe Tx algorithm for impetigo

Answer 27

Mild disease - hydrogen peroxide.
Signs of infection but systemically well - topical abx (fusidic acid)
Systemically unwell/widespread rash - oral flucloxacillin.

Question 28

Describe vitiligo (Px, Ax, Tx)

Answer 28

Amelanocytic patches, worse in summer monrths as UV exposure darkens skin.

Autoimmune condition, associated with other AIDs (thyroid disease - so Ix this).

No Tx required, but options include topical steroids, topical calcineurin inhibitors, phototherapy.

Question 29

What virus causes viral warts?
How are they treated?

Answer 29

HPV
In kids, 50% disappear in 6m.
More persistent in adults but clear up eventually. Most popular Tx include keratolytics (salicylic acid), cryotherapy etc.

Question 30

How do you treat oral / genital herpes?

Answer 30

Aciclovir shortens duration

Question 31

How do you treat shingles?

Answer 31

Acyclovir - reduces severity of post-herpetic neuralgia (most common Cx).

Question 32

How do you treat scabies?

Answer 32

Whole family should be treated (even without Sx). Wash all clothes and bedding on a hot wash.

Permethin cream applied to all areas then washed off after 8-12hrs. Repeat 1 week later.

Other options - benzyl benzoate emulsion, malathion lotion.

Question 33

What is the difference between lichen sclerosus and lichen simplex

Answer 33

Lichen Sclerosus - loss of collagen, autoimmune basis. Severe pruritus at night with pink-white papules (sclerosus = white). May do biopsy as premalignant. Tx w/ ultra-potent steroid cream over 12wks.

Lichen simplex - dermatitis/eczema is a chronic inflammatory skin condition. Also itchy and thicken, hyper/hypopigmentation. Tx w/ moderately potent steroid creams.