Psoriasis is a multisystem non contagious auto-immune inflammatory disease it is characterized by raised areas of abnormal skin and joint involvement, erythematous papules and plaques covered with silvery scales.

Causes:
• Genetic
• Immunological
• Injection
• Extreme temperature
• Stress

Symptoms:
• Lesions are pruritic and are most localized on scalp
• Extensor surface of elbows and knees, sacrum, buttocks and genitals, arthritis (5 – 30%) 
• Plaques are elevated, palpable lesions > 10 mm diameter.
• Pain in joints
• Depression
• Itching
• Joint stiffness
• Small dents in nails symptoms
• Emotional stress