Page 57 - LECTURE NOTES

7. Arthropathic psoriasis. Arthritis may accompany any variety of psoriasis in about ten

per cent of patients. Psoriatic arthritis may take several forms. The commonest type
is asymmetrical oligoarthritis, other types are: symmetrical seronegative rheumatoid-

like disease , distal interphalangeal involvement( most characteristic, but relatively
rare), axial skeletal involvement, and a destructive mutilating form (arthritis mutilans)

The typical lesions of psoriasis have the following features;

The lesions are very well marginated with distinct border and are raised above the surface.

The plaques usually have a diameter of one to several centimeters and have a round or oval

shape. The lesions may merge together to give rise to geographic patterns. The lesions are

covered with silvery white, mica-like, loosely adherent scales which, on removal may
reveal punctate bleeding points (Auspitz sign)

Symmetry: the lesions are symmetrically disposed on extensor surfaces of the body. Typical

sites of affection are the elbows, knees, shin, knuckles, sacral areas and scalp.

Management of psoriasis

Topical therapy is generally indicated when psoriasis is limited to less than 20% of the

body surface.
Explain to the patient the recurrent nature of the disease.

Anthralin

Salicylic acid ointment has been traditionally used for its keratolytic effect. Either alone
or in combination with coal tar or topical corticosteroids, salicylic acid (2% to 10%) helps

to soften and remove psoriatic scale.
Coal tar 5-10% Ultraviolet Radiation although coal tar has been used to treat psoriasis

for decades, its mechanism of action is still not well understood. Some studies have
shown that coal tars inhibit DNA synthesis, thus acting as a cytostatic

Moisturizer (Vaseline, urea 10 ointment of cream) and expose to sun. Moisturizer

(Emollients) help to hydrate, soften, and loosen psoriatic plaques
A strong topical steroid once or twice daily, cover with salicylic acid 2- 10 if necessary.

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