The symptoms of pityriasis rosea may progress in three distinct stages. However, not everyone who has the condition will experience the first or second stages described below.
Some people with pityriasis rosea have initial symptoms a few days to a week before the skin rash appears.
These can include:
- a high temperature (fever) of 38ºC (100.4ºF) or above
indigestion and/or an upset stomach
- lack of appetite
- joint pain
- a general sense of feeling unwell
These symptoms will usually pass by the time you reach the secondary rash stage (see below).
The herald patch
The next stage is usually the appearance of a red, oval patch of scaly skin that grows larger over the course of a few days. This is known as the herald patch. It ranges in size from 2-10cm (0.8-4 inches).
The patch usually appears on the trunk (the upper section of your body that includes the abdomen and chest) or neck. Less commonly, the patch can appear on the face, scalp, or on or near the genitals.
A secondary skin rash will usually develop within a few days to two weeks after the appearance of the herald patch, and it may continue to spread over the following two to six weeks.
The rash is made up of smaller raised scaly patches that usually range in size from 0.5 - 1.5cm. Most people will develop multiple patches across their trunk, neck, upper arms and upper thighs. The face is usually unaffected.
In light-skinned people, the patches are usually a pinkish-reddish colour. In dark-skinned people, the patches can sometimes be grey, dark brown or black.
The patches usually form a symmetrical 'Christmas tree pattern' on the upper back and a v-shape across the chest. They come together to form multiple downward slanting triangular lines that look similar to the branches of a fir tree.
The secondary rash isn't painful, but it can be itchy. The itchiness can range from mild to severe. It's often made worse by sweating and wearing tight-fitting clothing.
In most cases, both the herald patch and the secondary rash will clear within twelve weeks, although some symptoms occasionally persist for up to six months.
After the rash has disappeared you may notice some darkened or lightened areas of skin. These should return to normal within a few months. Pityriasis rosea doesn't cause scarring.
When to seek medical advice
If you think that you may have pityriasis rosea, see your GP to help confirm the diagnosis and ensure that other possible causes of your rash are not overlooked. Pityriasis rosea is not associated with any serious complications, so there's no need to be concerned.
If you develop blistering, soreness, or involvement of your eyes, genitals or mouth, you should seek medical advice immediately, as this may indicate another more serious condition.