International Journal of Clinical & Medical Images

A 40-year-old man presented with itchy erythematous lesions on his arms and upper back of 10-month duration. There was no history of joint pain. Family history was negative for similar skin problems. Physical examination revealed erythematous plaques with scales on his arms and upper back. Scraping of the scales resulted in fine punctate bleeding. He also had pitting of the nails. Plaque psoriasis or psoriasis vulgaris is characterized by sharply demarcated, erythematous, round or oval, plaques with loosely adherent silvery-white micaceous scales. Removal of the scales results in fine punctate bleeding (Auspitz sign). The lesions are usually symmetrically distributed and pruritic.

Typical sites include the knees, elbows, arms, torso, and scalp. Involvement of the scalp, face, and the intertriginous and diaper areas is more common in infants and young children. Skin lesions tend to persists for months to years and intermittent flares are common. New lesions may form at the site of trauma (Koebner phenomenon). Mucosal involvement is unusual. Seronegative inflammatory arthritis develops in about 30% of patients. Psoriatic arthritis can precede, coincide with, or follow the development of the skin lesions. Most patients eventually develop nail involvement which includes pitting, discoloration, onycholysis, or onychodystrophy. Nail involvement precedes the skin lesions in approximately 4% of patients. Complications of psoriasis include an increased risk of non-melanoma skin cancer and emotional distress in more severely affected individuals. Occasionally, patients with psoriasis may also develop uveitis and inflammatory bowel disease. Estimates of prevalence range from 1 to 2%. Approximately 25% of patients develop the disease before 20 years of age. Both sexes are affected equally. The condition is more common in Caucasian individuals than in black or Asian individuals. The prevalence is greatest in northern, colder climates, and the disease is more severe in the colder months. A family history of psoriasis in a first-degree relative is present in about 30% of patients with childhood-onset psoriasis.