Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Plaque psoriasis, the most common form, usually produces plaques of red, raised, scaly skin affecting the scalp, elbows, and knees.
The plaques may itch or burn.
Plaque psoriasis on the elbow. Image courtesy of Hon Pak, MD.
The flare-ups can last for weeks or months. Psoriasis can spontaneously resolve only to return later (chronic).
Plaques: They vary in size (1 centimeter to several centimeters) and may be limited or quite extensive. The shape of the plaque is usually round with irregular borders. Smaller plaque areas may merge, producing wide areas of involvement.
Plaque psoriasis. Image courtesy of Hon Pak, MD.
The skin in these areas, especially when over joints or on the palms or feet, can split and bleed.
Plaque psoriasis with fissures, which are splits in the skin. Fissures usually occur where the skin bends (joints). The skin may bleed and is more susceptible to infection. Image courtesy of Hon Pak, MD.
Plaques sometimes have an area around them that looks like a halo or ring (Ring of Woronoff).
Red color: The color of the affected skin reflects the inflammation present and is caused by increased blood flow.
Scale: The scales are dry, thin, and silvery white. The thickness of the scales may vary. When the scale is removed, the skin underneath looks smooth, red, and glossy. This shiny skin usually has small areas that bleed (Auspitz sign).
Symmetry: Psoriatic plaques tend to appear symmetrically on both sides of the body. For example, the psoriasis is usually present on both knees or both elbows.
Psoriasis of the scalp. Image courtesy of Hon Pak, MD.
Nails: Nail changes are common in psoriasis. The nails may have small indentations or pits. The nails can be discolored and separate from the nail bed at the fingertip. (See Nail Psoriasis.)
Nail psoriasis. Note the classic pits and yellowish color in the nails. Image courtesy of Hon Pak, MD.
Psoriasis in children: Plaque psoriasis looks slightly different in children compared to adults. In children, the plaques are not as thick, and the affected skin is less scaly. Psoriasis may often appear in the diaper region in infancy and in flexural areas in children. The disease more commonly affects the face in children as compared to adults.
Other areas: Although the most common body areas affected are the arms, leg, back, and scalp, psoriasis can be found on any body part. Psoriasis can be found on the genitals or buttocks, under the breasts, or under the arms. These areas can feel especially itchy or burning.
Psoriasis on the palms. Image courtesy of Hon Pak, MD.