What is rosacea?
Rosacea is a chronic rash involving the central face that most often affects those aged 30 to 60. It is common in those with fair skin, blue eyes and of Celtic origin. It may be transient, recurrent or persistent.
What is the cause of rosacea?
There are several theories regarding the cause of rosacea, including genetic, environmental, vascular and inflammatory factors. Chronic exposure to ultraviolet radiation plays a part.
The skin's innate immune response appears to be important in rosacea, as high concentrations of antimicrobial peptides such as cathelicidins have been observed. Cathelicidin is important as part of the skin's normal defence against microbes. Cathelicidin promotes infiltration of neutrophils in the dermis and dilation of blood vessels. Neutrophils release nitric acid also resulting in vasodilation. Fluid leaks out of these dilated blood vessels causing swelling (oedema); pro-inflmamatory cytokines leak into the dermis, and increase the inflammation.
Matrix metalloproteinases (MMPs) such as collagenase and elastase also appear important in rosacea. These enzymes remodel normal tissue and help in wound healing and production of blood vessels (angiogenesis). But in rosacea, they are in high concentration and may contribute to cutaneous inflammation and thickened, hardened skin. MMPs may activate cathelicidins contributing to inflammation.
Hair follicle mites (Demodex folliculorum) are sometimes observed within rosacea papules but their role is unclear. An increased incidence of rosacea has been reported in those who carry the stomach bacterium, Helicobacter pylori, but most dermatologists do not believe it to be the cause of rosacea.
Rosacea may be aggravated by facial creams or oils, and especially by topical steroids.
Rosacea used to be called 'acne rosacea' but it is quite different from acne. There are red spots (papules) and sometimes pustules in both conditions, but in rosacea they are dome-shaped rather than pointed and there are no blackheads, whiteheads, deep cysts, or lumps. Rosacea may also result in reddened skin, scaling and swelling of affected areas.
Characteristics of rosacea include:
- frequent blushing or flushing
- a red face due to persistent redness and/or prominent blood vessels - telangiectasia (the first stage or erythematotelangiectatic rosacea)
- red papules and sometimes pustules on the nose, forehead, cheeks and chin often follow (inflammatory or papulopustular rosacea). Rarely it involves the trunk and upper limbs
- dry and flaky facial skin
- aggravation by sun exposure and hot and spicy food or drink (anything that reddens the face)
- sensitive skin: burning and stinging, especially with make-up, sunscreens and other facial creams
- red, sore or gritty eyelids including papules and styes (posterior blepharitis), and sore or tired eyes (conjunctivitis, keratitis, episcleritis) - ocular rosacea
- enlarged unshapely nose with prominent pores (sebaceous hyperplasia) and fibrous thickening (rhinophyma)
- firm swelling of other facial areas including the eyelids (blepharophyma)
- persistent redness and swelling or solid oedema of the upper face due to lymphatic obstruction - Morbihan disease.
Rosacea - Images copyright DermNet (NZ)
|Mild papules and erythema
||Severe erythema, papules and pustules|
|Inflammatory papules and early rhinopyma
Rosacea may occasionally be confused with or accompanied by other facial rashes, including:
- acne vulgaris [most common type of acne]
- pyoderma faciale [skin condition occurring in young adult women which can resemble severe acne or rosacea]
- steroid rosacea [condition caused by use of potent topical steroids]
- perioral dermatitis [common facial skin problem in adult women, affecting skin around the mouth, eg. chin, cheeks, upper lip area]
- seborrhoeic dermatitis [common, harmless, scaling rash occurring mostly where skin is oily]
- irritant contact dermatitis [dermatitis caused by contact with chemical or physical agent].
In most cases, no investigations are required and the diagnosis of rosacea is made clinically. Occasionally a skin biopsy is performed, which shows chronic inflammation and vascular changes.
General measures to improve rosacea
General measures include:
- where possible, reduce factors causing facial flushing
- avoid oil-based facial creams and use water-based make-up
- never apply a topical steroid to the rosacea as although short-term improvement may be observed (vasoconstriction and anti-inflammatory effect), it makes the rosacea more severe over the next weeks (possibly by increased production of nitric oxide)
- protect yourself from the sun. Use light, oil-free facial sunscreens
- keep your face cool to reduce flushing: minimise your exposure to hot or spicy foods, alcohol, hot showers and baths, and warm rooms.
Medications used in treatment
Tetracylcine antibiotics including doxycycline and minocycline reduce inflammation. They reduce the redness, papules, pustules and eye symptoms of rosacea. The antibiotics are usually prescribed for 6 to 12 weeks, the duration and dose depending on the severity of the rosacea. Further courses are often needed from time to time as the antibiotics don't cure the disorder.
Sometimes other oral antibiotics such as cotrimoxazole or metronidazole are prescribed for resistant cases.
Anti-inflammatory effects of antibiotics are under investigation. They have been show to inhibit MMP function and in turn reduce cathelicidins and inflammation. The effective dose of tetracyclines in rosacea is lower than that required to kill bacteria, so they are not working through their antimicrobial function. Disadvantages of long term antibiotics include development of bacterial resistance, so low doses have been advocated that do not have antimicrobial effects (eg. 40-50mg doxycycline daily).
Metronidazole cream or gel can be used intermittently or long term on its own for mild cases and in combination with oral antibiotics for more severe cases.
Azelaic acid cream or lotion is also effective, applied twice daily to affected areas.
When antibiotics are ineffective or poorly tolerated, oral isotretinoin may be very effective. Although isotretinoin is often curative for acne, it may be needed in low dose long term for rosacea, sometimes for years. It has important side effects and is not suitable for everyone.
Medications to reduce flushing
Nutraceuticals targeting flushing, facial redness and inflammation may be beneficial.
Certain medications such as clonidine (an alpha2-receptor agonist) and carvedilol (a non-selective beta blocker with some alpha-blocking activity) may reduce the vascular dilatation (widening of blood vessels) that results in flushing. Side effects are usually mild but may include low blood pressure, gastrointestinal symptoms, dry eyes, blurred vision and low heart rate.
Oral non-steroidal anti-inflammatory agents such as diclofenac may reduce the discomfort and redness of affected skin. Although these are uncommon, serious potential adverse effects include peptic ulceration, renal toxicity and hypersensitivity reactions.
Calcineurin inhibitors such as tacrolimus ointment and pimecrolimus cream are reported to help some patients with rosacea.
Persistent telangiectasia can be successfully improved with vascular laser or intense pulsed light treatment. Where these are unavailable, cautery, diathermy or sclerotherapy (strong saline injections) may be helpful.
Rhinophyma can be treated successfully by a dermatologic or plastic surgeon by reshaping the nose surgically or with carbon dioxide laser.
Original material provided by the New Zealand Dermatological Society Inc. (DermNet NZ), May 2012 and reviewed by everybody, September 2012.