Psoriasis is a relatively easy case to get in finals - often seen when asked to examine a patients hands or specifically to examine the psoriatic rash.
source: dermatology.co.uk
Examining psoriasis
Observe the patient as a whole - look for any generalised skin changes - in particular, on the extensor surfaces of the limbs, scalp and
if possible, the back and navel. Look for psoriasis plaques - typically appears as raised areas of inflamed skin covered with silvery white scaly skin.
When inspecting the hands, start by looking at the nails. Look for pitting, ridging, onycholysis, hyperkeratosis and discolouration. See the example below.
picture source: prof-nail.nl
Follow this by inspecting the fingers, which are often sausage shaped.
Next examine the joints (20% of patients with psoriasis suffer with psoriatic arthritis) - the pattern is similar to that of rheumatoid arthritis, but the DIPJs may also be involved. There may also be monoarthritis of larger joints.
Common examiner questions:
What are the different types of psoriasis?
Plaque psoriasis (psoriasis vulgaris) - this is the most common form of psoriasis. It affects 80 to 90% of people with psoriasis.
Flexural psoriasis (inverse psoriasis) - appears as smooth inflamed patches of skin.
Guttate psoriasis is characterized by numerous small oval (teardrop-shaped) spots. It is associated with streptococcal throat infection.
Pustular psoriasis - commonly presents on the hands and feet. Raised lesions consisting of non-infectious pus (pustules).
Nail psoriasis - nail changes as discussed above
Psoriatic arthritis - as above
Erythrodermic psoriasis - a severe form of psoriasis, involving the widespread inflammation and exfoliation of the skin over most of the body surface.
