In dark-skinned people the patches can sometimes be grey, dark brown or black. Both the herald patch and rash usually last for 2 to 12 weeks, although they can last for up to 5 months.
After the rash has gone, you may have some darker or lighter areas of skin. These should return to normal within a few months and will not leave permanent scarring. See a GP if you have an unexplained rash. They'll usually be able to confirm whether it's pityriasis rosea, or another skin condition such as eczema , psoriasis or ringworm. If the GP is uncertain, they may refer you to a skin specialist dermatologist. A fine rash of small spots starts to appear within a week of the first patch appearing.
The spots become small oval patches that are coloured red to tan. The patches seem crinkly and loose in the centre.
The rash may be itchy. The upper body and upper arms are usually affected. The patches may follow the ribs in lines. The rash may spread to the upper thighs.
Occasionally, the rash may spread to include the neck and lower face. Causes of pityriasis rosea Pityriasis rosea is caused by a viral infection. Diagnosis of pityriasis rosea Pityriasis rosea can be mistaken for skin conditions such as tinea a fungal skin infection also known as ringworm or psoriasis, so careful diagnosis is needed. Treatment for pityriasis rosea It is not possible to make the rash disappear any faster, so treatment aims to manage the symptoms.
Options may include: Avoid using soap as this can irritate the rash. Bathe using plain water or some kind of moisturiser, such as bath oil. Steroid creams can be used to help reduce itching. Oral antihistamines may help in cases of severe itching. Mild moisturising creams can be applied generously and often. If your child uses this form of therapy, make sure he or she is protected from sunburn, which can sometimes make a rash worse.
Light therapy might be prescribed for cases where the itching is really bothersome. Usually, this involves ultraviolet B UVB therapy and is done by a dermatologist. Reviewed by: Julio E. Pajaro, MD. Larger text size Large text size Regular text size.
What Is Pityriasis Rosea? What Causes Pityriasis Rosea? Pityriasis rosea is more likely to show up in the spring and fall. It is an oval pink or red plaque 2—5 cm in diameter, with a scale trailing just inside the edge of the lesion like a collaret.
Pityriasis rosea: herald patch Pityriasis rosea. A few days after the appearance of the herald patch, more scaly patches flat lesions or plaques thickened lesions appear on the chest and back. A few plaques may also appear on the thighs, upper arms and neck but are uncommon on the face or scalp.
These secondary lesions of pityriasis rosea tend to be smaller than the herald patch. They are also oval in shape with a dry surface.
Like the herald patch, they may have an inner collaret of scaling. Some plaques may be annular ring-shaped. Pityriasis rosea plaques usually follow the relaxed skin tension lines or cleavage lines Langer lines on both sides of the upper trunk.
The rash has been described as looking like a fir tree. It does not involve the face, scalp, palms or soles. Pityriasis rosea: secondary rash Pityriasis rosea. Pityriasis rosea is said to be atypical when diagnosis has been difficult.
Atypical pityriasis rosea may be diagnosed when the rash has features such as:. Pityriasis rosea is associated with reactivation of herpesviruses 6 and 7, which cause the primary rash roseola in infants.
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