Malar rash
Template:Short description Template:More citations needed Template:Infobox medical condition (new) A malar rash (Template:Ety), also called butterfly rash,<ref name=":0">Template:Cite book</ref> is a medical sign consisting of a characteristic form of facial rash. It is often seen in lupus erythematosus. More rarely, it is also seen in other diseases, such as pellagra, dermatomyositis, and Bloom syndrome.
Many conditions can cause rashes with a similar appearance to a malar rash.<ref name=":0" /> A malar rash is present in approximately 46–65% of people with lupus.
DefinitionEdit
A malar rash of lupus is red or purplish and mildly scaly. It has the characteristic shape of a butterfly, and involves the bridge of the nose. Notably, the rash spares the nasolabial folds of the face, which contributes to its characteristic appearance. It is usually macular with sharp edges, and not itchy. The rash can be transient or progressive with involvement of other parts of the facial skin.Template:Citation needed
While some literature has described the slapped-cheek rash of fifth disease as a malar rash, it differs slightly in that the nose is typically spared.<ref>Template:Cite journal</ref>
Differential diagnosisEdit
Conditions that can cause rashes with a similar appearance to a malar rash include:
- lupus erythematosus<ref name=":1">Template:Cite journal</ref>
- pellagra<ref>Template:Cite journal</ref>
- dermatomyositis<ref>Template:Cite journal</ref>
- Bloom syndrome<ref>Template:Cite journal</ref>
- Rosacea, a long-term skin condition characterized by a red rash, usually on the face.
Lupus causes up to 96% of all cases of malar rash.<ref name=":1" /> Where lupus is suspected, further medical tests and a detailed history and examination are necessary to differentiate it from other conditions.Template:Citation needed These tests may include a test for the presence of anti-nuclear antibody in the blood as a screening test, which is not specific for lupus erythematosus.Template:Citation needed
EpidemiologyEdit
A malar rash is present in approximately 46–65% of people with lupus,<ref name="Houman2004" /><ref name=":2" /> with an average of 57% of lupus patients having it across all populations.<ref name=":1" /> This percentage varies between different populations.<ref name="Houman2004">Template:Cite journal</ref><ref name=":2">Template:Cite journal</ref>
HistoryEdit
A malar rash is often known more colloquially as a butterfly rash due to its distinctive appearance.<ref name=":0" />
See alsoEdit
ReferencesEdit
External linksEdit
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