Discoid rash - Red, raised patches of skin associated with scaling and plugging of the hair follicles. . Photosensitivity - Rash after exposure to sunlight. . Neurologic disorder - Seizures or psychosis, without other causes. . If 4 or more of these criteria are present at any time during the course of the disease, a diagnosis of systemic lupus can be made with 98 percent specificity and 97 percent sensitivity. These criteria are, however, weighted.
Different docs weight the different criteria differently.
So having 4 may not be enough, if you don't have the right 4.