Definition:
Psoriasis is a common, genetically determined,
inflammatory skin disorder of unknown cause,
classically characterized by well-demarcated,
erythematous plaque surmounted by a silvery
scale that preferentially localize to the extensor
surfaces of the body.
PSORIASIS. The extensor surfaces of the limbs are commonly affected.
Features of classic psoriatic lesion:
The classic psoriatic lesion is well-demarcated, erythematous papule or plaque surmounted by a silvery scale.
When the scales are removed, it produces bleeding surfaces called Austpz’s sign.
Keobner phenomenon: psoriatic lesion developed at the site of trauma.
The psoriatic lesions are remarkably symmetrical in distribution.
Most commonly located in the extensor surfaces limbs; pressure points: knee, elbow; scalp and ears; anogenital area: glutial cleft and glans penis.
Sometimes involves intertriginous area called- inverse psoriasis.
The classic psoriatic lesion is well-demarcated, erythematous papule or plaque surmounted by a silvery scale.
When the scales are removed, it produces bleeding surfaces called Austpz’s sign.
Keobner phenomenon: psoriatic lesion developed at the site of trauma.
The psoriatic lesions are remarkably symmetrical in distribution.
Most commonly located in the extensor surfaces limbs; pressure points: knee, elbow; scalp and ears; anogenital area: glutial cleft and glans penis.
Sometimes involves intertriginous area called- inverse psoriasis.
Factors causing flare-ups of Psoriasis
Classically affects the distal interpalangeal joints.
But more often it occurs as asymmetric arthritis involving small and medium-sized joints.
Rheumatoid factor is usually negative.
There is a distinctive and destructive form of arthritis that is specific to psoriasis.
Onset usually follows skin manifestations of psoriasis.
Treatment includes: NSAIDs, Methotrexate, Cyclosporine, Retinoids, Physical therapy etc.
1. TRAUMA. (Kobner phenomenon).
2. INFECTION.
(beta-haemolytic streptococcal infection often precede guttate psoriasis).
3. SUNLIGHT. Rarely, UV radiation worsen psoriasis.
4. DRUGS.
Antimalarials, beta-blockers, lithium, alcohol (abuse), Rapidly tapering corticosteroids (systemic or potent topical).
5. EMOTION.
PSORIATIC ARTHRITIS ( 5-10% )
Classically affects the distal interpalangeal joints.
But more often it occurs as asymmetric arthritis involving small and medium-sized joints.
Rheumatoid factor is usually negative.
There is a distinctive and destructive form of arthritis that is specific to psoriasis.
Onset usually follows skin manifestations of psoriasis.
Treatment includes: NSAIDs, Methotrexate, Cyclosporine, Retinoids, Physical therapy etc.
ERYTHRODERMIC PSORIASIS. The skin is universally involved. In some areas, it is red (erythrodermic ) and in other areas, it is scaling (exfoliating).
Typical plaque-like lesion disappears, the skin is universally red and scaly. The patient who is seriously ill suffers from:
Heat loss--hypothermia.
Water loss—dehydration.
Hyperdynamic circulation.
Loss of protein, electrolytes.
GUTTATE PSORIASIS. Small droplike (guttate ) red scaly papules occur on the trunk after a streptococcal throat infection.
Mainly seen in children.
Occurs 2-4 weeks after an episode of streptococcal throat infection.
Characteristically ‘drop’-sized lesions develop suddenly and at the same time.
The lesion resolves within 2-4 weeks.
Psoriasis of the palms and soles
Psoriasis of the palm and sole presents a difficult therapeutic challenge. Two variants:
Hyperkeratotic: Plaques are well-demarcated and scaly.
Its location presents additional problems-pain, fissuring and bleeding.
