Article about rosacea - technical
Rosacea is a common condition that usually begins after the second to third decade of life. Clinically, rosacea is characterized by central facial erythema that may wax and wane in intensity, erythematous papules, pustules, and telangiectasias.
Facial flushing is a common feature. The presence of telangiectasia and the occurrence of flushing help distinguish rosacea from acne, as does the absence of comedos. The clinical course of rosacea is chronic, with periods of exacerbation and remission.
Common triggers of rosacea include alcohol, exercise, extremes of temperature, and hot or spicy foods. Medications that produce vasodilation, such as niacin, can precipitate flushing and exacerbate rosacea.
Clinical Subtypes of Rosacea
Various subtypes of rosacea are recognized.
Papulopustular (inflammatory) rosacea
Papulopustular (inflammatory) rosacea is characterized by erythema (most commonly involving the cheeks, nose, inner forehead and chin), telangiectasias, and inflammatory lesions (papules and pustules).
Erythematotelangiectatic rosacea is characterized by diffuse erythema and telangiectasia with no or very few inflammatory lesions.
Ocular rosacea is common and can include blepharitis and conjunctival hyperemia or, less commonly, iritis, episcleritis, superficial punctuate keratopathy, and corneal neovascularization.
Phymatous rosacea is fortunately uncommon overall, occurring more frequently in males. It is characterized by localized sebaceous hyperplasia and fibrosis with development of bulbous and lobular proliferations of affected tissue. The nose (rhinophyma) is the most commonly affected anatomic site.
The pathogenesis of rosacea is poorly understood, although several associated mechanisms have been reported. Proliferation of commensal Demodex mites may play a role, with papulopustular involvement through stimulation of inflammatory pathways, but it is not believed to be a major factor in many cases. It has been suggested that Helicobacter pylori may play a role in the pathogenesis of rosacea, although this theory remains controversial. There is no definitive evidence that any bacterium plays a role in the pathogenesis of rosacea. Several vascular inflammatory and tissue degradative mechanisms are believed to be operative, including increased facial blood flow, oral-thermal flushing, upregulation of reactive oxygen species (ROS) with reduced antioxidant reserve in skin, and upregulation of matrix metalloproteinase enzymes (MMPs) involved in dermal matrix degradation.
The diagnosis of rosacea is made on the basis of clinical evaluation. There is no definitive diagnostic testing or histologic pattern that confirms the diagnosis.
No curative therapy is available for rosacea, although treatment may effectively reduce severity of visible signs and symptoms and may control the intensity and frequency of rosacea flares. Therefore, it is important for the clinician to define treatment goals and set expectations with patients. It is also important to characterize the subtype of rosacea, because different clinical features respond differently to specific forms of therapy. Optimal therapeutic results often require a combination of medical and physical treatment modalities.
Avoidance of triggers such as alcohol, hot or spicy foods, and heat is an important part of the therapeutic regimen offered to patients with rosacea. Sunscreens are likewise useful to reduce erythema, decrease telangiectasia formation, reduce production of ROS, and decrease dermal matrix degradation. Skin sensitivity increases in rosacea, as a result of an inherent increase in transepidermal water loss. Therefore, daily use of a gentle cleanser and a moisturizer is a vital component of the overall treatment program. Proper skin care has been shown to augment the therapeutic benefit of topical medical treatment for rosacea.
Several medications are helpful for the treatment of inflammatory lesions and perilesional erythema. Topical therapies that are effective for papulopustular rosacea of mild to moderate severity include sulfacetamide-sulfur, metronidazole, and azelaic acid. Trials of topical therapy should be continued for 8 to 12 weeks to assess response. When successful, therapy markedly decreases inflammatory lesions and partially reduces erythema and disease-related symptoms (e.g., stinging and burning). Topical agents may be used in combination with systemic therapy in patients with more severe involvement.
Systemic therapy for rosacea has conventionally utilized oral antibiotics, especially tetracycline derivatives (e.g., tetracycline, doxycycline, minocycline). Although there is no definitive evidence that the antimicrobial action of these agents contributes to their efficacy against rosacea, tetracyclines have several anti-inflammatory effects unrelated to antimicrobial activity, such as downregulation of several MMPs, and these anti-inflammatory effects may provide much of the therapeutic benefit in rosacea.
Doxycycline monohydrate in an anti-inflammatory dose, formulated as a 40 mg controlled-release capsule taken once daily, is approved by the FDA for the treatment of inflammatory rosacea, including long-term treatment. This formulation differs from other available tetracycline formulations, including doxycycline, in that it results in blood levels below those required for antibiotic activity without loss of anti-inflammatory activity, as long as it is administered no more than once daily.
Data for both short-term treatment (16 weeks' efficacy data) and long-term treatment (safety data over 9 months and microbiologic data up to 18 months) with doxycycline in an anti-inflammatory dose have indicated therapeutic benefit without production of antibiotic-resistant bacterial flora.
Microbiologic assessments have included evaluation of flora from the mouth, skin, gastrointestinal tract, and genitourinary tract. In large-scale pivotal clinical trials, no women treated with anti-inflammatory-dose doxycycline developed vaginal candidiasis.
Persistent diffuse facial erythema seen after adequate medical treatment of papulopustular rosacea, diffuse facial erythema seen with erythematotelangiectatic rosacea, telangiectasias, and phymas are poorly responsive to topical and systemic therapies. In such cases, physical modalities such as properly selected laser therapy, intense pulse light (IPL), or both are warranted.