Where are psoriasis plaques most commonly found on the body?

Where are psoriasis plaques most commonly found on the body?

• A. Extensor surfaces
• B. Flexor surfaces
• C. Palmar surfaces
• D. Mucosal surfaces

Answer: (A)

Extensor surfaces are the most common sites for psoriasis plaques, especially on the elbows and knees, and these plaques often involve the scalp and trunk as well. The plaques are typically well-defined, erythematous, and covered with a silvery scale, reflecting the rapid turnover of epidermal keratinocytes driven by T-cell–mediated inflammation. In contrast, involvement of skin folds (inverse psoriasis) or mucosal surfaces is less common, and while palms and soles can be affected in palmoplantar psoriasis, that pattern is not the typical starting location.

Extensor surfaces are the most common sites for psoriasis plaques, especially on the elbows and knees, and these plaques often involve the scalp and trunk as well. The plaques are typically well-defined, erythematous, and covered with a silvery scale, reflecting the rapid turnover of epidermal keratinocytes driven by T-cell–mediated inflammation. In contrast, involvement of skin folds (inverse psoriasis) or mucosal surfaces is less common, and while palms and soles can be affected in palmoplantar psoriasis, that pattern is not the typical starting location.