When diagnosing
rosacea, dermatologists need to examine a person's symptoms, because there are no tests available to diagnose the disease. However, on rare occasions, skin biopsies can pinpoint rosacea.
There are very few people who have all of the symptoms of this disorder, which can make diagnosing rosacea difficult. If a patient has family members with the condition, doctors will usually make a rosacea diagnosis, even if there are only a few apparent symptoms.