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Mini Series Part 1

What is Rosacea?

Rosacea, pronounced (Roh-Zay-Sha), is a chronic inflammatory skin condition, still not completely understood. Rosacea is also one of the most frequently treated and managed skin disorders amongst clinicians. In 2002, the National Rosacea Society Expert Committee established a classification system for the condition to assist in the standardisation of its diagnosis amongst clinicians. The committee divided Rosacea’s diagnostic criteria into primary and secondary characteristics.

Primary: Involves the presence of more than 1 of the following features; - Flushing (transient erythema, or redness) - Non transient erythema, or redness - Papules and pustules - Telangiectasia, or visible blood vessels

Secondary: Involves the presence of more than 1 of the following features; - Burning or stinging - Plaques - Dry appearance - Oedema, or swelling - Ocular manifestations - Peripheral location - Phymatous alterations

Further, the committee also allocated rosacea into four distinct subtypes based on the manifestation of primary and secondary features. A single patient may bestow with multiple subtypes concurrently, and whether or not a patient may advance from one subtype to another remains debated.

Subtype I: Erythematotelangiectatic rosacea

Erythematotelangiectatic rosacea is represented by non-transient incidents of flushing and persistent facial erythema (redness). The regions of redness may assume the peripheral face, ears, neck and upper aspect of the chest, though the periocular area is often afforded. Telangiectasia (visible blood vessels) are also a common feature, however they are not mandatory for a diagnosis. Patients suffering from Erythematotelangiectatic rosacea often have a lessened limit for irritation and topically applied substances and products can possibly aggravate their symptoms. Histologically, Erythematotelangiectatic rosacea encompasses dilation of the superficial blood vessels and low grade perivascular lymphohistiocytic inflammation with occasional plasma cells.

Subtype II: Papulopustular rosacea

Papulopustular rosacea also awards the characteristics observed in Erythematotelangiectatic rosacea, though, patients additionally endure transient papules or pustules in a central facial distribution. In more severe instances, these episodes of inflammation can result in facial oedema (swelling). Histologically, papules enclose perivascular and perifollicular inflammatory infiltrate containing lymphocytes, neutrophils and plasma cells in the superficial and mid-dermis. The pustular lesions have a collection of neutrophils and extend beyond the follicle.

Subtype III: Phymatous rosacea

Phymatous rosacea is symbolised by thickened, enlarged skin with uneven surface nodularities. These alterations can occur in sebaceous facial regions, such as the nose (rhinophyma), chin (gnathophyma), the forehead, (metophyma), the ears (otophyma) or the eyelids (blepharophyma). Histologically, there is hyperplasia, or enlargement of the sebaceous gland, follicular plugging, telangiectasia, distinct thickening and fibrosis of the dermis and large deposits of dermal mucin.

Subtype IV: Ocular rosacea

Presently, there is no diagnostic test for Ocular rosacea, therefore the diagnosis relies merely on the physician’s clinical judgment. Ocular rosacea bestows with watery or bloodshot eyes, foreign body sensation, burning or stinging, dryness, itching, light sensitivity, blurred vision, telangiectasias of the conjunctiva and lid margin or lid and periocular erythema, blepharitis, conjunctivitis and irregularity of the eyelid margins. Chalazion and sty’s are also usual features. Ocular rosacea is said to occur in 6-50% of patients who present with cutaneous rosacea, though the gravity of ocular symptoms may not always link with the severity of cutaneous features.

Who develops Rosacea? The incidence and epidemiology of rosacea has been scarcely investigated; therefore, the present data is limited. Though, research has been able to determine the following:

  • Rosacea is more prevalent in lighter skinned individuals, such as Celtic and Northern European descents, and is less commonly recognised in darker skins.

  • Rosacea is found to have a significantly greater chance of developing for those with a positive family history of the condition

  • Rosacea mostly affects women

  • Although rosacea can develop at any age, it is suggested to arise after the age of 30. Women are more universally diagnosed with rosacea, though men are more severely affected, with Phymatous rosacea affecting more males than females

  • According to the National Rosacea Society, it is estimated 415 million people worldwide are affected by rosacea, with 95% of patients knowing little to nothing regarding the signs and symptoms prior to their diagnosis

What does Rosacea look like?

Dependent on both primary and secondary diagnostic criteria’s, and the four subtypes, rosacea can clinically manifest any of the following:

  • Persistent redness resembling a blush or a sunburn

  • Skin thickening

  • Flushing or facial redness accompanied by heat, warmth or burning. This feature is non-transient, in that it may come and go

  • Small, red, solid bumps or pus-filled pimples accompanied by burning and stinging

  • Visible blood vessels may arise on the cheeks, nasal bridge and other areas of the central face

  • The eyes may appear watery and bloodshot and the eyelids may also become red and swollen. Crusts and scale can also accumulate around the eye region

  • Burning or stinging sensations in conjunction with itching and feelings of skin tightness

  • Swelling of the face

  • Plaques or small red patches

  • Dry, rough and scaly central facial region

What causes Rosacea? Rosacea is a condition of multifactorial origin and currently its exact pathogenesis remains unclear. Studies proclaim the following are the main culprits in its advancement.

- UV light radiation and exposure: UV increases reactive oxygen species (ROS) in the skin, which then activates the inflammatory cascade which has been shown to trigger flushing and worsen Rosacea’s symptoms

- Genomic association: Owing to the higher incidence of rosacea in individuals of Celtic and Northern European descent, research suggests there may be a genetic element to the development of the disorder. Though genomic studies have been unsuccessful in recognising a causative gene, rosacea sufferers do have an increased expression of a variety of genes that play roles in both innate and adaptive immune systems

- Dysregulation of innate immune system: Under normal physiologic conditions, the activation of the innate immune system results in controlled increases in cytokines and antimicrobial peptides (AMP’s) in the skin, but in patients with rosacea, these normal signalling pathways seem to be disrupted.

- Microorganisms: Microorganisms such as Demodex folliculorum, Staphylococcus epidermidis, Helicobacter pylori and Bacillus oleronius have all been hypothesised to play roles in the development of rosacea; however, their role remains unclear. Specifically, to the demodex mite, while they are a common inhabitant of normal healthy human skin, they have been known to prefer and colonise in regions of skin affected by rosacea. Also, there are numerous exacerbating factors which play a role in aggravating the disorder for its sufferers, such as alcohol intake, caffeine consumption, hot drinks, heat exposure, smoking, spicy foods, hot baths or showers and stress.



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Forton, F., & De Maertelaer, V. (2018). Diagnostic Indicators of Rosacea and Demodicosis. Acta Dermato Venereologica,.

Gether, L., Overgaard, L., Egeberg, A., & Thyssen, J. (2018). Incidence and prevalence of rosacea: a systematic review and meta-analysis. British Journal of Dermatology.

Gonzalez-Hinojosa, D., Jaime-Villalonga, A., Aguilar-Montes, G., & Lammoglia- Ordiales, L. (2018). Demodex and rosacea: Is there a relationship? Indian Journal Of Ophthalmology, 66(1), 36–38.

McAleer, M. A., Fitzpatrick, P., & Powell, F. C. (2010). Papulopustular rosacea: Prevalence and relationship to photodamage. Journal of the American Academy of Dermatology, 63(1), 33-39.

National Rosacea Society. (2019). All About Rosacea. - National Rosacea Society.

Okhovat, J., & Armstrong, A. W. (2014). Updates in Rosacea: Epidemiology, Risk Factors, and Management Strategies. Current Dermatology Reports, 3(1), 23-28.

Steinhoff, M., Buddenkotte, J., Aubert, J., Sulk, M., Novak, P., Schwab, V. D., Mess, C., Cevikbas, F., Rivier, M., Carlavan, I., Déret, S., Rosignoli, C., Metze, D., Luger, T. A., & Voegel, J. J. (2011). Clinical, Cellular, and Molecular Aspects in the Pathophysiology of Rosacea. Journal of Investigative Dermatology Symposium Proceedings, 15(1), 2-11.

Tan, J., & Berg, M. (2013). Rosacea: Current state of epidemiology. Journal of the American Academy of Dermatology, 69(6), 27-35.

Two, A. M., Wu, W., Gallo, R. L., & Hata, T. R. (2015). Rosacea: Part I. Introduction, categorization, histology, pathogenesis, and risk factors. Journal of the American Academy of Dermatology, 72(5), 749–758.

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