Psoriasis Flashcards
Define plaque psoriasis
Chronic systemic inflammatory skin condition -> erythematous plaques with a silver scale
What are the risk factors for plaque psoriasis?
Genetic predisposition = PSORS1
Environmental triggers = stress on the skin such as scratching causing new skin lesions (Koebner phenomenon), infection (HIV, streptococcal pharyngitis for guttate), medication
Smoking
Alcohol consumption
Obesity
What is the basic pathology of plaque psoriasis?
Abnormal immune reaction involving an innate and an adaptive response = hyperproliferation or keratinocytes
Angiogenesis and inflammation contribute to erythema and inc vascular permeability.
Cytokines released by inflammatory cells trigger a positive feedback system = leading to maintenance of chronic inflammation.
What are the key signs and symptoms of psoriasis?
Erythematous plaques with a silver
Typically on extensor surfaces and scalp
Ausptiz sign - removal of scale leads to pinpoint bleeding due to rupture of capillaries in there demise
Typically has periods of remission and flare up.
What are the different types of psoriasis?
Plaque psoriasis (vulgaris) = most common
Guttate - small randrop sized lesions - young children and adults (post infection)
Inverse - folds of skin, tend to be smooth, sting and lack of scale due to moisture in these area
Pustular -
Psoriatic arthritis - joint involvement
What investigations tend to be done for psoriasis?
Diagnosis - appearance of skin
Specific tests to confirm:
Skin biopsy - parakeratosis (retained nuclei), ancanthosis (increase thickness) and elongation of the rete ridges
Blood tests - rule out differentials and co-morbs - FBC, LFT, renal profile, cholesterol levels, fasting glucose, ESR
Rheumatology screen - RF and anti-CPP
What scoring system is used in psoriasis?
PASI - psoriasis area severity index - consider SA and intensity of plaque redness, thickness and scaling
What co-morbidities should be considered in psoriasis?
Cardiovascular disease - QRISK2
Mental health
Metabolic syndrome - blood glucose, central obesity, HTN,
What treament should be offered for psoriasis initially?
Topical Vitamin D analogues - calcipitriol
Topical Coritcosteroids - for mild to moderate disease - up to 4 weeks in adults, 2 weeks in children.
What additional treatment may be given to help patients with psoriasis after topical creams?
Phototherapy - narrow UVB therapy - moderate to severe
Systemic non-biological therapies - methotrexate, cyclosporin, acitrenin - severe disease
Biological therapies - atenercept, ustekinumab
Lifestyle modification - health weight, abstain from smoking and limit alcohol intake, stress management techniques.
What are some potential complications of psoriasis?
Psoriatic arthiritis - joint pain and swelling, eye inflammation.
Cancer - lymphoma and non-melanoma skin cancer.
Infections - skin or streptococcal pharyngitis
Where does the psoriasis rash tend to occur?
Scalp
Elbow
Gluteal cleft
Genitalis
Knees
Toenails/finger nails
Ears
Umbilicus
What are the key features of the psoriasis rash?
Salmon pink
Well demarcated
Plaques
Silverly adherent scale (flakes off)
What are the key nail changes seen in psoriasis?
Onycholysis - seperated from bed
Pitting
Subungual hyperkeratosis - grows away from nail bed
What is koebernisation in psoriasis?
When new psoriasis lesions occur in areas of skin damage - such as scratching.
How to differentiate between eczema and psoriasis on the scalp?
Eczema - lighter flaking, can extend beyond the scalp (seb derm)
Psoriasis - stronger scaly, confined to margin of the scalp
What is pustular psoriasis?
When pus-filled blisters/pustules occur on the skin - superimposed on psoriasis plaques
Can be mild (localised) or severe (generalised)
