Although we know that rosacea is a common condition, it is consistently underdiagnosed. Worldwide, approximately 5.5% of the population is affected by rosacea, but an analysis of medical coding showed only 1% of patients with the condition receive a diagnosis of rosacea.1 This underdiagnosis of rosacea also is seen in the United States, where only 18% of the estimated 16 million Americans with rosacea are receiving treatment.2
Challenges in Identifying Patients
Many factors impede the diagnosis and treatment of rosacea. As the demands of health care providers accelerate and patient loads increase, identification of disease processes outside of a patient’s chief complaint becomes more challenging.
Providers should be prepared to discuss rosacea with patients suspected of having the disease. Patients often are unaware that the redness on their face is a treatable condition. When questioned about it, patients often respond with statements such as “this is what my face has always looked like” or “it is just like my mom and sisters’ skin, too.”
Therefore, it is important to thoroughly educate patients about the disease process and treatment options. Patients must understand that rosacea is a chronic and progressive condition. It is a hypersensitivity of the blood vessels in the face, and it is a disorder that is treated, not cured. Primary care providers also must understand the importance of the psychological burden of rosacea and the effect that appropriate treatment can have on a patient’s overall quality of life.
The pathophysiology of rosacea is multifactorial. It tends to be a disease of middle age and occurs more frequently in women. Rosacea appears to have a strong genetic predisposition, as patients diagnosed with the condition are approximately 4 times more likely to have a family member who also has rosacea.3 Rosacea is more common in individuals of Northern European descent.2 There also is an environmental component to the disease process. Triggers can include, but are not limited to, exposure to heat or cold, hot beverages, stress, spicy food, and alcohol.
Two distinct pathways lead to rosacea: neurovascular dysregulation and aberrant innate immune response.2 There is significant documentation validating the role of the vascular system in rosacea.4,5 In the neurovascular pathway, there is evidence of an increase in activation of transient receptor potential vanilloid cation channels as well as in bradykinin, nitric oxide, and reactive oxygen species.5 These increases can lead to the release of inflammatory cytokines, inflammation, vasodilation, erythema, and sensory symptoms, such as burning and stinging. Evidence of the second pathway, an aberrant immune response, includes an increase in toll-like receptor 2, kallikrein 5, and cathelicidins, which in turn leads to inflammation, the release of inflammatory cytokines, and angiogenesis.2,5 Together, these pathways lead to the pathognomonic clinical symptoms of rosacea, which include transient flushing, erythema, edema, papules and pustules, telangiectasia, and ultimately sebaceous gland hypertrophy or phymatous changes.
Other factors thought to be associated with rosacea include a disruption in skin barrier function, likely secondary to abnormalities in the stratum corneum and epidermal fatty acid composition that result in increased transepidermal water loss, dryness, and skin irritability.6
There also has been an association of the demodex mite with rosacea-prone skin, although it is not known if the mite is a causative agent or if it is present due to the desirable environment that rosacea-affected skin provides.7
Classification of Disease
In 2002, an expert panel of the National Rosacea Society began efforts to standardize the classification and diagnosis of rosacea.8 The panel placed importance on organizing rosacea into subtypes with distinct features, clinical presentations, symptoms, and treatments, with the following severity levels: grade 1 (mild), grade 2 (moderate), and grade 3 (severe). The 4 main subtypes are erythematotelangiectatic rosacea (ETTR), papulopustular rosacea (PPR), phymatous rosacea, and ocular rosacea.
Under the 2002 classification, ETTR is characterized by skin sensitivity, persistent or intermittent flushing/blushing, and a feeling of warmth or burning on the skin of the malar region of the cheeks. Episodic occurrences frequently are associated with exposure to the triggers mentioned previously. Clinically, patients present with a centrofacial distribution of telangiectasia and erythema in varying degrees of severity. Severity is based on the frequency of flushing, the amount of erythema, and the quantity of telangiectasia.8
PPR is considered when a patient presents with a history of intermittent acne-like bumps that often occur in response to triggers. Severity is based on the quantity of papules and pustules and presence of erythema and edema.8
Phymatous rosacea is characterized by varying degrees of patulous follicles, fibrosis, and sebaceous hyperplasia. Rhinophyma and, less frequently, fibrotic changes to the skin of the chin, forehead, ears, or eyelids occur. Severity is based on the degree of swelling and hypertrophy and the presence of nodules.8
Ocular rosacea often overlaps with one of the other subtypes. However, when not accompanied by concomitant cutaneous changes, this condition can be quite challenging to accurately diagnose.8
The 2002 classification system was implemented as a foundation that could be built on as understanding of the pathophysiology and pathogenesis of rosacea advanced. One of the shortcomings of this system was that a patient could present concomitantly with multiple phenotypes. Additionally, these subtypes did not take into account nonvisible symptoms or histologic changes associated with rosacea.