Psoriasis is characterized by which of the following skin changes?

Explanation: The primary assessment technique used to diagnose psoriasis is a physical examination of the skin. The characteristic red, raised patches with silver scales are indicative of psoriasis. While additional tests like skin biopsy may be used to confirm the diagnosis, the initial diagnosis is based on the visual appearance of the skin lesions.

Incorrect choices: a. A skin biopsy may be performed to confirm the diagnosis of psoriasis, but it is not the primary assessment technique used to diagnose the condition.

b. Blood tests may be conducted to rule out other conditions or assess for systemic involvement, but they are not the primary method of diagnosing psoriasis.

d. MRI is not a diagnostic tool for psoriasis. It may be used in certain cases to assess joint involvement in psoriatic arthritis, but it does not diagnose psoriasis itself.

Explanation: The presence of at least 3 typical psoriasis plaques on the body is one of the essential diagnostic criteria for confirming psoriasis. These plaques are characterized by well-defined, erythematous (red), raised lesions with silvery-white scales.

Incorrect choices: a. Positive skin biopsy showing eosinophils infiltration: While a skin biopsy may be performed to support the diagnosis of psoriasis, the presence of eosinophils is not specific to psoriasis and can be found in various skin conditions.

b. Family history of autoimmune diseases: A family history of autoimmune diseases may increase the risk of developing psoriasis, but it is not a definitive diagnostic criterion for the condition.

d. Elevated erythrocyte sedimentation rate (ESR) on blood test: An elevated ESR can indicate inflammation in the body, but it is not specific to psoriasis and may be present in other inflammatory conditions as well.