What is pityriasis rosea?

Pityriasis rosea is characterized primarily by red patches on the skin, often starting with a single large patch known as a "herald patch." This skin condition typically presents as oval or round lesions that can be slightly scaly and are usually accompanied by mild itching. The rash can spread to different areas of the body in a pattern that sometimes resembles the shape of a Christmas tree.

While it can sometimes be associated with viral infections, it is not classified strictly as a viral infection itself, nor is it accurately described as a form of eczema or a fungal infection. Eczema is characterized by inflammation and can present differently. Fungal infections typically cause discoloration and may involve distinct symptoms such as itching and scaling, which are not the primary features of pityriasis rosea. Hence, the description of pityriasis rosea as a skin disease that causes red patches is the most fitting and accurate representation of its defining characteristics.