dermatologic disorders
Psoriasis
Symptoms and Signs of Psoriasis
Lesions are either asymptomatic or pruritic and are most often localized on the scalp, extensor surfaces of the elbows and knees, sacrum, buttocks (commonly the gluteal cleft), and genitals. The nails, eyebrows, axillae, umbilicus, and perianal region may also be affected. Plaques may look violaceous in patients with dark skin and pink or red in patients with light skin, but key features such as scaling and distribution (eg, on extensor elbows, trunk, legs, and periumbilical area) are consistent across all skin tones. The disease can be widespread, involving confluent areas of skin extending between these regions. Lesions differ in appearance depending on type. Psoriasis typically manifests as plaques covered with thick, silvery, shiny scales. Plaques are elevated, palpable lesions>10 mm in diameter. Image provided by Thomas Habif, MD. This image shows psoriatic plaques. Plaques may look violaceous in patients with dark skin tones, but key features such as scaling and distribution (eg, on extensor elbows, trunk, legs, and periumbilical area) are consistent across all skin tones. Image courtesy of Karen McKoy, MD. This photo shows erythematous plaques covered with silvery-white scales on the extensor surface of the elbows. This appearance is typical of plaque psoriasis. SCIENCE PHOTO LIBRARY This photo shows patches of scaly, erythematous, and thick skin, and discolored, crumbly nails. DR. HAROUT TANIELIAN/SCIENCE PHOTO LIBRARY This photo shows red, flaky, and thickened skin on the scalp of a patient with psoriasis. DR P. MARAZZI/SCIENCE PHOTO LIBRARY This photo shows irregular pits and areas of yellow-brown discoloration (oil spots) in a person with psoriasis. © Springer Science+Business Media The photo on the left shows thickening and crumbling of the nail of the great toe. Pitting and onycholysis are visible on the hand (right), suggesting nail psoriasis as the diagnosis. © Springer Science+Business Media This image shoes widespread pustules on the soles of a patient with erythrodermic pustular psoriasis. Image courtesy of Karen McKoy, MD. This photo shows pustular lesions on the tip of a finger in a patient with acrodermatitis continua of Hallopeau (a localized form of pustular psoriasis). © Springer Science+Business Media In inverse psoriasis, red, shiny patches (sometimes without scales) form in the intertriginous areas such as the inframammary fold. SCIENCE PHOTO LIBRARY This photo shows multiple plaques on the trunk of a 22-year-old man with guttate psoriasis. DR P. MARAZZI/SCIENCE PHOTO LIBRARY This photo shows a diffuse erythematous rash on the torso of a patient with erythrodermic psoriasis. SCIENCE PHOTO LIBRARY This photo shows hyperkeratotic discrete plaques on the palm of a patient with palmoplantar psoriasis. SCIENCE PHOTO LIBRARY This photo shows hyperkeratotic discrete plaques on the sole of a patient with palmoplantar psoriasis. SCIENCE PHOTO LIBRARY This photo shows erythematous macules and pustules on the foot of a patient with pustular psoriasis. Image courtesy of Karen McKoy, MD. Among the various psoriasis subtypes (see table), plaque psoriasis (psoriasis vulgaris or chronic plaque psoriasis) accounts for about 90%; lesions are discrete, erythematous papules or plaques covered with thick, silvery, shiny scales. Lesions appear gradually and remit and recur spontaneously or with the appearance and resolution of triggers. Arthritis develops in 5 to 30% of patients and can be disabling ( Psoriatic Arthritis ); joint destruction may ultimately occur. Psoriasis is rarely life-threatening but can affect a patient’s self-image. Besides the patient's appearance, the sheer amount of time required to treat extensive skin or scalp lesions and to maintain clothing and bedding may adversely affect quality of life. 