Psoriasis is a chronic, immune-mediated inflammatory skin disease, which ranges in severity from a few scattered red, scaly plaques to involvement of almost the entire body surface. It may progressively worsen with age, or wax and wane in its severity; the degree of severity depends on inheritance and environmental factors.

It is a complex disease, multiple exogenous and endogenous stimuli incite already stimulated innate immune responses in genetically predetermined individuals. The disease process is a result of a network of cell types including T cells, dendritic cells and keratinocytes that, with the production of cytokines, generate a chronic inflammatory state.

Vitiligo is a chronic disorder of pigmentation characterized by the development of white macules on the skin due to loss of epidermal melanocytes.

Its pathogenesis is still unclear, many mechanisms and theories have been suggested including autoimmunity, auto cytotoxicity, biochemical and neuronal mechanisms.

There are multiple patterns of psoriasis including plaque, guttate, pustular, inverse and erythrodermic, approximately 80% of patients present with plaque psoriasis which is clinically characterized by well demarcated erythematous plaques with overlying scales. These plaques can be intensely pruritic and bleed when manipulated, referred to as the Auspitz sign. Lesions are usually distributed symmetrically and frequently occur on the elbows, knees, lower back and scalp.

Prevalence of psoriasis is around 2-3% of the general population. A high prevalence of psoriasis at the rate of 11.8% has been reported from Kazach'ye, located in the Arctic region of the former Soviet Union.

In Egypt, the prevalence reported is around 3%. A study was done in hospitals of Damietta governorate reveals that prevalence of psoriasis is about 5%. Up to the investigator's knowledge the prevalence of psoriasis at Assuit governorate is not known till now.

Vitiligo can be classified into segmental or non-segmental. Non-segmental or generalized vitiligo is the most common clinical presentation and often involves the face and acral regions.

Prevalence of vitiligo is 0.5%-2% of general population world-wide, without predilection for sex or race. A previous study on skin diseases I Assiut governorates reveals that prevalence of vitiligo was about 1.22%.

Inclusion Criteria:

• The study will performed on people who live in rural areas in Assuit governorate (all households) regardless of sex or age.

Exclusion Criteria:

• no exclusion criteria

The study will performed on people who live in rural areas in Assuit governorate (all households) regardless of sex or age.