Psoriasis Flashcards
(33 cards)
What causes psoriasis?
Exact cause unknown
Genetic factors
Immune factors and inflammatory cytokines
Environmental factors = stress, excessive alcohol, smoking, skin trauma
Summarise the pathophysiology of psoriasis
Abnormal maturation of dermis –> over proliferation epidermis –> inflammation and redness, crusting of skin
What are the characteristics of plaque psoriasis?
Well demarcated
Pink plaques with silvery scales
May be single or numerous lesions
May be itchy but usually asymptomatic
Where is plaque psoriasis usually found?
outside of elbows
knees
sacrum
lower back
What are the characteristics for scalp psoriasis?
Thick patches can cover entire scalp, may extend slightly past hairline (facial psoriasis)
Mild hair loss (temporary, my be severe)
May be first or only site, can co-exist with other forms of psoriasis
What are the characteristics of nail psoriasis?
pitting, yellow, ridging nails
Onycholysis may be present
one or more nails
May have chronic plaque psoriasis, psoriatic arthritis
Summarise psoriatic arthritis
painful, inflammatory condition of joints
Pain and swelling of joints/stiff joints
Severe joint damage
What are the characteristics of guttate psoriasis?
Looks like a shower of red, scaly tear drops on body
Lesions are pink, scaling less noticeable
Occurs at any age, good chance of spontaneous resolution
Where is guttate psoriasis usually found?
Trunk
Upper arms
thighs
What causes guttate psoriasis?
streptococcal throat infections
What are the characteristics of flexural psoriasis?
More moisture = different appearance
Smooth, well-defined patches –> may be shiny, little scales
Where is flexural psoriasis usually found?
body folds
genitals
e.g.: armpits, groin, under breast, navel, natal cleft, penis, vulva
What is palmoplantar pustulosis?
Similar to psoriasis, can be in combination w/ psoriasis
Crops of pustules, red, scaly, thickened skin
localised to palms and soles
What are some differential diagnoses to psoriasis?
Dermatitis = less plaque, no silver scale, usually on flexors, more itchy
Tinea = active outer border and clear centre, most common in toe nails
Seborrheic dermatitis = can progress to psoriasis, will respond to antifungals
Summarise the treatment options for psoriasis
Emollients
Coal Tar preparations
Topical corticosteroids
Dithranol
Vit D analogous
Calcineurin inhibitors
Phototherapy
Systemic treatments = immunosuppressants, acitretin, apremilast, biotherapies
What is the role of keratolytic in psoriasis?
Salicylic acid preparations –> soften scales, allow other meds to penetrate
Weak antifungal and antibacterial activity
How often should keratolytics be applied?
2-3 times a day
Thin layer, wash hand after use
May cause irritation/stinging to surrounding (broken) skin
What is the proposed mechanism of coal tar preparations in psoriasis?
reduce epidermal thickness
antipruritic
weakly antiseptic
What coal tar preparations are used in psoriasis?
Coal tar (crude) or liquid coal tar (LPC)
1% crude coal tar = 5% LPC
Cream, ointment, other formulation
What are some topical corticosteroids used in psoriasis?
hydrocortisone
betamethasone
mometasone
triamcinolone
What is the role of corticosteroids in psoriasis treatment?
Anti-inflam = manage/reduce redness and inflammation
Antimitotic = reduce skin cell turnover
Most common treatment for initial control
What is dithranol?
Compounded ointment or paste (Lazzar’s) = also known as anthralin
Usually applied and washed off depending on strength, stains things (skin, everything)
keep in dark place, if turn brown/purple –> no longer effective
What are some available Vitamin D analogues for psoriasis?
Calcipotriol = calcipotriene (never alone)
Combinations with betamethasone are also present
Outline some guidelines about the application of Vit D analogues in psoriasis? (areas to avoid, freq, things to consider)
Avoid skin folds, face
Apply once a day for 4 weeks
large areas, apply less freq
Protect area from sunlight
