Rash of pityriasis rosea
The first sign of pityriasis rosea is often one large patch on the skin, which is followed smaller patches or bumps.
If you develop pityriasis rosea, you may experience the following in this order:
Feel ill for 1 or 2 days
Develop a large patch on your skin
Get many smaller patches or bumps on your skin
See your skin clear
Pityriasis rosea often occurs this way, but not always. Some people develop a few large patches on their skin. It’s also possible to see only bumps.
Although signs and symptoms can vary, the following explains what generally happens when someone gets pityriasis rosea.
Before you see signs on your skin: Many people remember feeling sick for a day or two before a large patch or rash appears on their skin.
Flu-like symptoms
Before seeing any signs on your skin, you may develop a sore throat or flu-like symptoms.
A sore throat is the most common symptom. The lymph nodes in your neck may also feel swollen.
Other symptoms that can develop include:
Fatigue
Headache
Fever
Loss of appetite
Achiness
Nausea
Trouble sleeping
Large patch develops on the skin: As the flu-like symptoms clear, the first sign of pityriasis rosea appears on the skin. This is usually a single patch, which grows larger.
Large patches
Most people develop one large patch on their skin, but it’s possible to develop 2 or more large patches before the rash erupts.
Location of patches
The large patch usually develops on the back, chest, or abdomen; however, it can develop anywhere on the skin, including the armpit.
If you have light-colored skin, this patch tends to be oval, slightly raised, and pink to salmon in color. The center is often covered with fine white scale.
If you have darkly pigmented skin, this oval patch tends to look dusky violet to deep brown in color.
The patch can appear anywhere on the skin, but it often develops on the belly, chest, or back. No matter where it appears, it tends to grow, usually for about 2 weeks, before more patchers or spots appear.
As a large patch tends to be the first sign of pityriasis rosea, this patch is often given one of the following names:
Herald patch
Mother patch
Medallion lesion
Smaller patches or bumps: In about 2 weeks, smaller patches or tiny bumps often appear. People who have light-colored skin usually develop patches that look like smaller versions of the herald patch. If you have darkly pigmented skin, small, raised bumps tend to appear.
The rash can also look like another skin condition, such as hives, nummular eczema, or psoriasis.
Herald patch on light skin
People with light-colored skin tend to have a large patch and smaller patches.
Herald patch on dark skin
If you have darkly pigmented skin, the patch tends to be purple to brown in color and the rash usually appears as small bumps on the skin.
Most people develop the rash on their torso, and it’s usually densest on their belly.
While common on the chest, back, and belly, the rash can appear anywhere on your skin. It can also cover you from head to toe, although this is rare.
For about 10-14 days, the rash gradually spreads out, and you see new spots or bumps on your skin.
Rash remains the same: Once the rash stops spreading, it lasts for a few days to a few months.
Can look like hives
The pityriasis rosea rash can look like hives or another skin condition.
The skin clears: Some people see the rash go away within 6 to 8 weeks, but it can take 5 months or longer for the skin to clear.
No matter how long it takes to clear or what it looks like, there’s likely only one cause. You’ll find what researchers believe causes this disease at, Pityriasis rosea: Causes.
Images
Images from the Journal of the American Academy of Dermatology: 1,3,4,7: J Am Acad Dermatol. 2009;61(2):303-18
Getty Images: 2
Images used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides: 5, 6
References
Blauvelt A. “Pityriasis rosea.” In: Wolff K, Goldsmith LA, et al. Fitzpatrick’s Dermatology in General Medicine (seventh edition). McGraw Hill Medical, New York, 2008: 362-6.
Ciccarese G, Broccolo F, et al. “Oropharyngeal lesions in pityriasis rosea.” J Am Acad Dermatol 2017;77:833-7.
Drago F, Broccolo F, et al. “Pityriasis rosea: An update with a critical appraisal of its possible herpesviral etiology.” J Am Acad Dermatol 2009;61:303-18.
Habif TP, Campbell JL, et al. “Pityriasis rosea.” In: Dermatology DDxDeck. Mosby Elsevier, China, 2006:Card 42.
Julapali M, Travers JB. “Papulosquamous skin eruptions.” In: Fitzpatrick JE, et al. Dermatology Secrets Plus (5th edition). Elsevier. China, 2016:67-8.
Wood GS, Reizner GT. “Other papulosquamous disorders.” In: In: Bolognia JL, et al. Dermatology. (fourth edition). Mosby Elsevier, China, 2018:170-2.
