4.1.2 Rosacea

Acne Rosacea, Kupferfinne, Couperose, Copparosa.

Incidence: 165/100,000 per year, prevalence: in a 2018 study, the prevalence of rosacea was estimated at 5.46% of the general population and 2.4 % of all dermatologic outpatients.

Individuals with fair skin type have an increased risk. In patients of colour a large proportion of undiagnosed cases may exist.

Conflicting data on gender preference.

Age of onset 30 to 50 years; in rare cases rosacea can occur in children.

Multifactorial etiology:

• Environmental trigger factors (extreme temperatures, temperature changes, sunlight)

• Micro-organisms (demodex mites with symbiont Bacillus oleronius, possibly helicobacter pylori)

• Nutrition (caffeine, alcohol, hot and spicy foods)

• Body conditions (exercise, acute psychological stress, menstruation)

• Certain medications

Pathogenesis:

• Impaired permeability barrier in the stratum corneum (cytokine release leading to cutaneous inflammation)

• Antimicrobial peptides (defensin, cathelicidin)

• Overexpression of Toll-like receptors

• Inflammatory cells (adaptive immune cells, B lymphocytes): papules are characterized by increased Th1 and Th17 cells, plasma cells, mast cells, and macrophages

• Reactive oxygen species increased

• Angiogenesis (leading to telangiectasias)

• Sensory nerve activation (release of vasoactive neuropeptides)

• STAT1 and NPM1 TFs might contribute to the progression of rosacea by regulating inflammation and vasculature.

Type I (teleangiectatic): Flushing, telangiectatic erythema.

Type II (papulopustular): Flushing, telangiectatic erythema, centrofacial inflammatory papules and pustules.

Type III (phymatous): Rhinophyma, disfiguring growth of hyperplastic sebaceous glands on the nose and other facial regions.

Ocular rosacea.

Morbihan’s disease.

All subtypes show dilated lymph and blood vessels in the upper and mid-dermis and a superficial perivascular and perifollicular mononuclear lympho-histiocytic infiltrate. Oedema and thickened elastic fibres may be seen.

Type I: changes are sparse but teleangiectasia.

Type II: epithelia of follicular infundibula can show spongiotic changes and intrafollicular neutrophils (pustules) as well as lymphocytes, mast cells, macrophages (papule) in the infiltrates.

Type III: sebaceous glands are hyperplastic and granuloma formation and cysts develop. In the granulomatous subtype, non-caseating epithelioid cell granulomas arise. Demodex mites are found in around 10% of routine biopsies causing follicular dilation, folliculitis and perifollicular inflammation.

Elimination of triggers.

Type I: Topical: Brimonidine tartrate 0.33-1% gel 1x/d, oxymetazoline 1% cream.

Procedures: Nd: YAG Laser, pulsed dye Laser, intense pulsed light (IPL).

Type II: Topical: Metronidazole 0.75-1% cream or gel 2x/d, azelaic acid 20% cream/15% gel 2x/d, ivermectin 1% cream 2x/d, pimecrolimus 1% onitment 1x/d, tretinoin 0.025% cream 1x/d, adapalene 01.% cream 1x/d, permethrin 5% cream 1x/d, benzoyl peroxide 5% gel 1x/d, erythromycin 2% gel, dapsone 5% gel - Systemic: Doxycycline 50-200 mg/d in one or two doses, isotretinoin 0.15-0.3 mg/kg bw/d, zinc sulphate 100 mg/d.

Type III: Systemic: Isotretinoin 0.3 mg/kg bw/d and procedures: Surgical approach, including dermabrasion, ablative lasers.

Ocular rosacea: Systemic: Doxycycline 100 -200 mg/d