Pityriasis rosea (PR) is a common skin condition characterized by the appearance of a scaly and sometimes itchy rash throughout the body. Common sites for the PR rash include:

• Neck
• Chest
• Back
• Arms
• Upper thighs

PR was first identified in 1798 by British physician Robert Willan, who called it “roseola annulata” and described it as a self–limited eruption in otherwise healthy children. In 1860, French physician Camille Melchior Gibert gave the skin disease its present name: pityriasis, which stands for scaly, and rosea, which stands for the color pink. Pink patches of scaly skin appear on various parts of the body, usually beginning on the back.

Most cases of pityriasis rosea occur in healthy individuals without signs of illness. It is more common in women than men, and a vast majority of the time the disease affects children and young adults ages 10 to 35. However, it may occur at any age. The skin disease has a higher incidence during spring and fall.

Generally, PR is benign, self-limited and usually resolves on its own within eight to 16 weeks. The most common complications of PR are changes in the skin’s pigment (color), such as post-inflammatory hyperpigmentation (excessive pigmentation) and hypopigmentation (skin discoloration) in the affected areas. However, these conditions are normally not permanent and resolve on their own over time. Individuals with dark skin may also have long-lasting flat, brown spots after the rash has subsided. The condition does not cause scars.

PR may be confused with the lesions seen in secondary syphilis, a sexually transmitted disease. The use of certain drugs (e.g., antibiotics, heart medications, barbiturates) may cause some people to develop skin eruptions that resemble PR. In addition, the PR rash is similar to that seen in other skin disorders, including:

• Ringworm. A skin infection caused by a fungus.
  
  
• Psoriasis. A common skin inflammation resulting in scaly patches of itchy, dry skin.  
  
  
• Eczema. A chronic skin disorder characterized by an itchy and scaly rash.