Rosacea Awareness Month: Getting to know the causes, types & symptoms

Many of us suffer with occasional redness but persistent flushing can be a sign of rosacea, an inflammatory, long-term skin condition. One of our top queries at The Skin Nerd, 42% of respondents of our recent survey said they suffer from rosacea. What is more, this is a global concern - according to The National Rosacea Society, the skin condition affects 415 million people worldwide, with most sufferers aged over 30. We spoke to Dermatologist Dr Nicola Ralph, of The Institute of Dermatologists, Ireland, to learn more about this ultra common skin condition. 


What is rosacea? 

Rosacea is a chronic skin condition characterised by symptoms of facial flushing, as well as erythema, telangiectasia, coarseness of skin, and an inflammatory papulopustular eruption resembling acne.* ‘Rosacea affects approximately 10% of Irish adults,’ explains Dr Nicola Ralph, a dermatologist based in Dublin. ‘Also known as “the curse of the Celts,” rosacea presents as redness, easy flushing, and visible blood vessels and broken capillaries on the face, especially the central cheeks and nose. It also includes inflammatory lesions, which are small red spots and micropustules.’ Despite being incredibly common, many sufferers experience rosacea differently, with signs and symptoms presenting in different ways. 


The 4 main subtypes of rosacea 

Erythematotelangiectatic rosacea (ETR): Characterized by persistent redness within the central section of the face, this subtype is often accompanied by visible blood vessels (telangiectasiae). Those with this type of rosacea may also experience flushing, burning, stinging, and dryness of the skin.  


Papulopustular rosacea (PPR): This subtype is characterised by papules and pustules that resemble acne, along with redness and swelling of the central face. These symptoms may also be accompanied by burning and stinging sensations. There are no comedones (blackheads) like acne, and the skin does not scar from inflammatory rosacea.  


Phymatous rosacea: This is primarily characterised by thickening of the skin and enlargement of the nose, but it can also affect the chin and forehead. Irregular surface nodules and prominent pores may also be present. 


Ocular rosacea: This subtype affects the eyes and eyelids can cause uncomfortable symptoms such as inflammation, redness, dryness, tearing, and vision problems. 


‘Diagnosis of rosacea is typically based on a patient's symptoms and a physical examination by your doctor,’ Nicola informs The Skin Nerd. ‘There are no specific tests or diagnostic criteria for rosacea. However, your doctor may perform tests to rule out other conditions that may cause similar symptoms, such as lupus or seborrheic dermatitis.’ 


What causes rosacea? 

The exact cause of rosacea is not fully understood, but it is thought to be related to a combination of factors including: 

Genetics: Family history of rosacea, skin type (Fitzpatrick I or II), and specific genetic mutations (ApaI G/T) have all been reported as risk factors, suggesting a genetic component of the condition, however, more research is needs to be conducted on the causative genes. 

Microorganisms: ‘Demodex mites are a normal part of the skin flora and can be found in small numbers on the skin of most people. However, in people with rosacea, there is evidence that the density of Demodex mites may be slightly higher than normal and there may be more of a specific subtype of demodex mite, which may play a role in the development of rosacea,’ suggests Nicola. ‘The exact relationship between Demodex mites and rosacea is not fully understood, but one theory is that mites trigger an immune response in the skin, leading to inflammation and other symptoms of rosacea. Another theory is that the mites themselves release substances that contribute to the development of rosacea. However, the relationship between the mites and the condition is still a subject of research and debate.’ 

Immune system dysregulation: Much research on the immunology related to the development of rosacea has been conducted over the years, with studies suggesting that LL-37 (Cathelicidin antimicrobial peptide - which is said to play a role in immunomodulation, wound healing, and cell growth) may serve as a key contributor to the proinflammatory and proangiogenic (the process through which new blood vessels form from pre-existing vessels) effects, which are highly evident in the skin of patients with rosacea.*** 

Neurogenic dysregulation: There has been some evidence to suggest a pathogenesis of neurogenic dysregulation. For example, triggers such as stress or spicy food, could be aggravating factors for rosacea. Comorbidity research also suggests a close relationship between neurogenic dysregulation and rosacea, such as psychosis (e.g. depression) and neurological disorders (e.g., Parkinson's disease).  

Inflammation: A high rate of inflammatory response has been found in subjects with rosacea, suggesting a response or a trigger to immune, microorganisms, and neurogenic dysregulation progression.  

Abnormal barrier function: Increased TEWL and decreased stratum corneum hydration have been identified in those suffering with rosacea. This means that cleansing habits and skin care that support barrier function is key to managing the condition. However, cleansing at a high frequency or with a machine could also disrupt the delicate barrier and exuberate any problems, so care should be taken under the advice of a dermatologist. 



In 2022, the National Rosacea Society conducted a survey and collected responses from 1066 patients with rosacea. Aiming to investigate which factors can trigger or aggravate the symptoms of the disease, results revealed that the most prominent triggers were found to be sun exposure, emotional stress, and hot water. Food triggers include figs, bananas, plums, chocolate, cheese, yoghurts, soy sauce, spinach, beans, peas, and broad beans. Strong and hot coffee or tea, alcohol, and sweeteners added to drinks can act by activating transient receptor potential ion channels leading to functional impairment of the skin barrier. Although some patients with rosacea indicate that coffee has the potential to worsen symptoms, a large study provided opposite conclusions. The study by Li et al. found that 82,737 women with rosacea who consumed more caffeine had a lower risk of incident rosacea, highlighting its possible protective effect. Furthermore, the consumption of histamine-rich foods and sugary foods can also lead to rosacea exacerbations. ** 


If you suspect you have acne or rosacea, please visit your GP or dermatologist, who will be able to make a professional assessment of your skin.  



*Aimee M Two, Wiggin Wu, Richard L Gallo, Tissa R Hata, Journal of the American Academy of Dermatology 2015 May   

Xi-Min Hu,a,b Zhi-Xin Li,c Dan-Yi Zhang,c Yi-Chao Yang, c Sheng-Yuan Zheng,c Qi Zhang,b Xin-Xing Wan,d Ji Li,a,e,f, 

**Li et al, Current research and clinical trends in rosacea pathogenesis (2022)   

*** Pound LD, Patrick C, Eberhard CE, Mottawea W, Wang GS, Abujamel T, Vandenbeek R, Stintzi A, Scott FW. Cathelicidin Antimicrobial Peptide: A Novel Regulator of Islet Function, Islet Regeneration, and Selected Gut Bacteria. Diabetes. 2015 Dec;64(12):4135-47.