PSORIASIS

PSORIASIS

Psoriasis is a common chronic inflammatory skin diseases marked by circumscribed scaly macules affecting chiefly the extensor surfaces of the body.

Characteristic Lesion of Psoriasis:

• Sharply demarcated erythematous plaque with micaceous silvery white scale

• Histopathology

- Thickening of the epidermis

- Tortuous and dilated blood vessels.

Three Cardinal Signs of Psoriatic Lesions

1.Plaque elevation

2.Erythema

3. Scale

CLINICAL TYPES:

Guttate

Chronic Plaque

Flexural

Pustular

Nail Psoriasis

Erythroderma

Arthropathy

CLINICAL FEATURE

Affects ususeally extensor surfaces of the body

Dry well define erythematous macules, papules are present

A candle grease like scale can be repeatedly produced even from the non scaling lesion.

Complete removal of a scale produces pin point bleeding .

The lesions may develop along the scratch line .

The lesions may heal in the centre thus forming rings.

Life - Threatening Forms of Psoriasis:

A.Generalized Pustular Psoriasis

• Unusual manifestation of psoriasis

• Can have a gradual or an acute onset

• Characterized by waves of pustules on erythematous skin often after short episodes of fever of 39˚ to 40˚C.

• Weight loss

• Muscle Weakness

• Hypocalcemia

• Leukocytosis

• Elevated ESR

B.Erythrodermic Psoriasis

• Classic lesion is lost

• Entire skin surface becomes markedly erythematous with desquamative scaling.