How is the diagnosis of rosacea made?

The primary and secondary characteristics of rosacea described above are often associated. The most common groups of signs are referred to as subtypes specific to rosacea. Each subtype includes the fewest signs necessary to make a subtype diagnosis.

Patients may receive an incorrect diagnosis for skin conditions that present similar characteristics. Rosacea is often misdiagnosed as a common acne, photodermatitis, seborrheic dermatitis, or contact dermatitis. A differential diagnosis could take place and a skin biopsymay be performed to definitively rule out other diagnoses.

However, these recommendations are currently the subject of controversy. Martin SCHALLER and his colleagues have found that patients can simultaneously exhibit characteristics of several subtypes of rosacea, and that these characteristics can evolve between subtypes, making this method somewhat confusing. They propose a new foundation for diagnosis based on the "phenotype" rather than on the subtypes.

According to them, a phenotype-based approach could enhance outcomes by addressing the clinical presentation and taking into account the individual patient's experience. A consensus has emerged on the need to havecategorical scales effective for assessing the skin characteristics of rosacea. Furthermore, the severity of these characteristics should be evaluated on a five-point categorical scale including "mild/absent" and "almost mild/minimal", in addition to "mild", "moderate", and "severe".

After the clinical examination, the clinical situation can be stated and the treatments potential can be prescribed.