Pityriasis Rosea is a common skin disease characterized by a rash that can last anywhere between a few weeks to a few months. In most cases, the condition starts with a single, scaly, oval-shaped patch (or “herald patch”) on the chest or back and is a followed a week or two later with additional pink patches on the chest, arms, legs, and back. The face is not normally affected, however.
The initial “herald patch” ranges between 2 cm and 10 cm while the later patches are between 1 cm and 2 cm. Patches on the back often form a pattern that resembles the outline of a fir tree (or “Christmas tree”). The “herald patch” is sometimes mistaken for other conditions such as ringworm, psoriasis, or eczema. Prior to the appearance of the “herald” patch, one may experience symptoms such as tiredness, nausea, sore throat, and headaches.
The exact cause of Pityriasis Rosea is unknown but it is believed to be caused by a virus. The disease is not contagious and most commonly affects adolescents and young adults between the ages of 10 and 35. While one may contract Pityriasis Rosea at any time of the year, it is more commonly seen in the spring and fall. Dermatologists diagnose this condition by inspecting the rash but may also conduct blood tests and skin biopsies by examining skin samples from the affected area under a microscope. Potassium hydroxide tests can also be conducted to rule out fungal infections.
Treatment
For mild cases, no treatment may be required and the condition may go away on its own between 6 and 12 weeks. As a general rule of thumb, patients are encouraged to bathe or shower with plain water, bath oils, mild lubricants and creams, and other soap substitutes as soaps can aggravate the rash. Itching can be treated with steroid creams and ointment or taking antihistamines. More severe cases can be treated with ultraviolet light treatments (phototherapy).
