A malar rash (), also called butterfly rash, is a

medical sign Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

consisting of a characteristic form of facial

rash A rash is a change of the skin that affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracke ...

. It is often seen in lupus erythematosus. More rarely, it is also seen in other diseases, such as

pellagra Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth. Areas of the skin exposed to friction and radiation are typically affected first. Over tim ...

, dermatomyositis, and Bloom syndrome. Many conditions can cause rashes with a similar appearance to a malar rash. A malar rash is present in approximately 46–65% of people with lupus.

Definition

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. While some literature has described the slapped-cheek rash of

fifth disease Fifth disease, also known as erythema infectiosum and slapped cheek syndrome, is a common and contagious disease caused by infection with parvovirus B19. This virus was discovered in 1975 and can cause other diseases besides fifth disease. Fifth ...

as a malar rash, it differs slightly in that the nose is typically spared.

Differential diagnosis

Conditions that can cause rashes with a similar appearance to a malar rash include: * lupus erythematosus *

* dermatomyositis * Bloom syndrome * 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. Where lupus is suspected, further

medical test A medical test is a medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, or to determine a course of treatment. Medical tests such as, physical and visual exams, diagnostic imaging, genetic ...

s and a detailed history and examination are necessary to differentiate it from other conditions. 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.

Epidemiology

A malar rash is present in approximately 46–65% of people with lupus, with an average of 57% of lupus patients having it across all populations. This percentage varies between different populations.

History

A malar rash is often known more

colloquially Colloquialism (also called ''colloquial language'', ''colloquial speech'', ''everyday language'', or ''general parlance'') is the linguistic style used for casual and informal communication. It is the most common form of speech in conversation am ...

as a butterfly rash due to its distinctive appearance.

References

External links