Is a malar or "butterfly" rash always indicative of lupus? what else could it be?

Butterfly rash: A butterfly rash is not always from lupus. An irration rash can cause this as well as seborrhea.

Butterfly rash: I would like to add that rosecea is a common type of rash that can also appear to be like the type of rash you refer to.

Not always lupus: A malar or "butterfly" rash is one of the signs of possible lupus, but other rashes can appear similar, including eczema, rosacea, seborrheic dermatitis, allergic contact dermatitis, and others. A complete history, physical exam, and possible skin biopsy and/or blood test can usually distinguish between these rashes.