Demodex: the worst enemies are the ones that used to be friends

Evaluation of the relationship between Demodex infestation and obesity in rosacea patients

BACKGROUND

The changes in the skin caused by obesity may predispose patients with rosacea to Demodex infestation (DI). Besides, identifying predisposing factors in these patients is important for initial treatment plan.

AIMS

The main purpose of this study is to determine the relationship between DI and obesity in patients with rosacea.

METHODS

Sociodemographic characteristics, body mass index, and clinical features of 130 rosacea patients were recorded. Demodex density was measured by noninvasive standard skin biopsy, and a determination of ≥5/cm2 mites was regarded as positive for DI. Patients with a BMI of 30 and above were categorized as the obese group, and those with a BMI below 30 were classified as the nonobese group. Moreover, patients were divided according to DI into positive and negative. These groups were compared with each other.

RESULTS

Upon comparing the patients with and without obesity, it was noted that the obese patients had significantly higher rates of erythematotelangiectatic type rosacea, rosacea severity, and flushing complaints. Furthermore, results show that the DI was significantly more common in obese patients. The most determinant factors for predicting DI in rosacea patients were papulopustular type rosacea, obesity, and rosacea severity, respectively.

CONCLUSIONS

In this study, DI was found to be more common in obese patients with rosacea. Besides, obesity was found to be one of the most determining factors in detecting DI in patients with rosacea.

The Prevalence of Demodex spp. Infestation in Dermatological Patients in Northern Poland

The presence of Demodex spp. mites on the skin is a common phenomenon in the human population. In most people, it is an asymptomatic infestation, but in some patients, it can contribute to the occurrence of diseases such as demodicosis, rosacea, or blepharitis, as well as non-specific symptoms. In this study, the results of tests assessing the presence of Demodex spp. by direct microscopic examination (DME) in 2508 patients from northern Poland with the suspicion of demodicosis were retrospectively analyzed. A total of 3684 tests were performed. Among them, only 1585 (43.02%) revealed the presence of Demodex spp., while 2099 (56.98%) were negative. It was shown that in the analyzed population of patients with clinical suspicion of demodicosis, the degree of confirmation of the presence of Demodex spp. positively correlated with the patient's age (p = 0.001) and the mite was mainly found on the edges of eyelids and on the facial skin. Additionally, in men, the presence of Demodex was more often confirmed than in women (p = 0.004). In conclusion, the proper diagnosis of demodicosis still constitutes an important clinical problem due to the non-specificity of symptoms and the low confirmation of clinical suspicions of infestation by DME, especially in lower age groups.

Beyond the Surface: Understanding Demodex and Its Link to Blepharitis and Facial Dermatoses

Demodex represents the most frequent ectoparasite found in humans. Although Demodex mites are considered commensals of human pilosebaceous units, an abnormally high mite density can cause several ocular and cutaneous symptoms and signs, sometimes to a severe degree. Both Demodex spp. (folliculorum and brevis) play a significant part in eye pathology and facial dermatoses. These mites have been related to blepharitis, ocular rosacea, meibomian gland dysfunction and various skin diseases, including rosacea, demodicosis and seborrheic dermatitis. Understanding the importance of Demodex in both eye and skin conditions is crucial for accurate diagnosis and appropriate management strategies, which may involve targeted treatments to control the mite population and reduce associated symptoms.

The Association Between Acne Vulgaris, Acne Vulgaris with Nonspecific Facial Dermatitis, and Demodex Mite Presence

Background

Demodex mites can lead to various skin disorders, from non-specific dermatitis to conditions that mimic other diseases, making it challenging to diagnose accurately. Additionally, it has been reported that Demodex mites can cause skin conditions such as perioral dermatitis, pustular folliculitis, pityriasis folliculorum, blepharitis, and rosacea. Due to conflicting studies, there is a debate regarding the link between Demodex mites and acne vulgaris. This study aims to determine the prevalence of Demodex mites on the faces of individuals with acne vulgaris, acne with nonspecific facial dermatitis, and healthy facial skin to clarify the association.

Materials and Methods

This observational case-control study involved 120 participants aged 18-37: 40 individuals with acne vulgaris only, 40 with acne and nonspecific facial dermatitis, and 40 healthy controls. The same dermatologist examined and diagnosed all participants to ensure accuracy before being grouped. The Standardized Skin Surface Biopsy (SSSB) method was used to detect Demodex mites in all three study groups. Furthermore, additional samples were collected randomly from acne lesions using the Superficial Needle Scraping (SNS) method in the two acne groups.

Results

The study found no significant difference in Demodex prevalence and high Demodex density rate between patients with only acne vulgaris and the control group (p>0.05). However, acne patients with nonspecific facial dermatitis had a higher rate of Demodex prevalence and high Demodex density rate than the only acne vulgaris and control group (p<0.05). The clinical symptoms of nonspecific facial dermatitis in acne patients strongly associated with Demodex mites are patchy red, dry, scaly skin, roughness, insect bite-like papules, and flushing.

Conclusion

Demodex prevalence and high Demodex density rate are not associated with acne vulgaris. Still, it is associated with acne and nonspecific facial dermatitis, particularly in patients with patchy redness, dry, scaly skin, roughness, insect bite-like papules, and flushing.

Case Series of Demodicosis in Acne Vulgaris Patients

An abnormal density of Demodex mites can trigger many skin disorders known as demodicosis. Clinical manifestations of demodicosis may resemble other skin diseases and can coexist with other skin disorders, resulting in underdiagnosis and a more challenging diagnosis. Here, we report three cases of demodicosis in acne vulgaris patients. These case series have discussed their clinical features along with optimal strategies for diagnosis and treatment.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

Comparison of in vitro Killing Effect of Thai Herbal Essential Oils, Tea Tree Oil, and Metronidazole 0.75% versus Ivermectin 1% on Demodex folliculorum

Background

Abnormal proliferation of Demodex mites causes a skin disorder called demodicosis and has been linked to rosacea. The development of alternative therapy against Demodex mites is currently required. The ability to kill Demodex mites of Thai herbal essential oils has never been explored. This study aimed to study and compare the in vitro killing effect of Thai herbal essential oils, tea tree oil, and metronidazole 0.75% with ivermectin 1% on D. folliculorum.

Materials and Methods

D. folliculorum mites were collected from the wastes of diagnostic standardized skin surface biopsy samples of demodicosis and rosacea patients for the trial. The microscopic evaluation started immediately after the mites were exposed to immersion oil (negative control), Thai herbal essential oils, tea tree oil, metronidazole 0.75%, and ivermectin 1% (positive control). The survival times of ten mites from each test agent were compared.

Results

The efficacy of Thai herbal essential oils and other test agents can be arranged in order as follows: lemongrass oil > sweet basil oil > clove oil > tea tree oil > lesser galangal oil > ginger oil, kaffir lime oil, peppermint oil > citronella oil > galangal oil > cajeput oil > ivermectin 1% > metronidazole 0.75%.

Conclusion

This current study demonstrated the in vitro killing efficacy on D. folliculorum: Thai herbal essential oils, Tea tree oil > ivermectin 1% > metronidazole 0.75%. Thai herbal essential oils have the potential to be an adjuvant or alternative therapy against Demodex mites. Further in vivo studies are necessary to determine the treatment efficacy and side effects.

Demodicosis in Different Age Groups and Alternative Treatment Options-A Review

Infestation with Demodex mites is a common occurrence, especially in adults and the elderly. More recent attention has been paid to the presence of Demodex spp. mites in children, even ones without comorbidities. It causes both dermatological and ophthalmological problems. The presence of Demodex spp. is often asymptomatic, thus it is suggested to include parasitological investigation tests in dermatological diagnostics, in addition to bacteriological analysis. Literature reports show that Demodex spp. are related to the pathogenesis of numerous dermatoses, including rosacea or demodicosis gravis, and common eye pathologies reported by patients such as dry eye syndrome or ocular surface inflammatory conditions, such as blepharitis, chalazia, Meibomian gland dysfunction, and keratitis. Treatment of patients is a challenge and is usually prolonged, therefore it is important to carefully diagnose and properly select the therapy regimen for the treatment to be successful, and with minimal side effects, especially for young patients. Apart from the use of essential oils, research is ongoing for new alternative preparations active against Demodex sp. Our review was focused on the analysis of the current literature data on the available agents in the treatment of demodicosis in adults and children.

A hairy situation for ILC2s

The overall contribution of type 2 immunity to cutaneous barrier integrity is poorly understood. In this issue of Immunity, Ricardo-Gonzalez et al. demonstrate the mechanisms by which type 2 cytokines and group 2 innate lymphoid cells (ILC2s) regulate Demodex mite colonization and maintain skin homeostasis.

Comparison of in vitro Killing Effect of N, N-Diethyl-Meta-Toluamide (DEET) versus Permethrin on Demodex folliculorum

Background

There is no single effective treatment for demodicosis; successful treatment requires a multimodal approach. Relapse or recurrence of demodicosis is relatively high, making the therapy challenging. Several reports have documented the successful treatment of demodicosis with acaricidal agents, which aimed at reducing the excessive number of Demodex mites and improving the patients' symptoms. Reports of irritation and resistance to topical acaricidal agents have led to the search for effective alternative treatments.

Materials and Methods

A total of 100 standardized skin surface biopsy (SSSB) biopsy slides from 100 patients with demodicosis were randomly divided into five groups, each with 20 slides exposed to immersion oil, N, N-diethyl-meta-toluamide (DEET) 5%, 10%, 20%, and permethrin 1%, respectively. The microscopic evaluation started immediately after the test agents exposed the mites. The survival time (ST) was defined as the interval between the first exposure of Demodex folliculorum to the test agents to the time the movements ceased.

Results

The differences between the median ST of DEET 5% (44 min), 10% (22 min), and 20% (14 min) were significant when compared to the negative control group (240 min) with p<0.001, <0.001, <0.001, respectively. While the median ST of permethrin 1% (42 min) was not significantly different from the median ST of DEET 5% (p=0.7395).

Conclusion

This study demonstrated the dose-related acaricidal effect of DEET on D. folliculorum. The survival times of DEET 5%, 10%, and 20% were significantly shorter than the negative control (immersion oil). DEET 5% had a comparable in vitro killing effect as permethrin 1%. Further in vivo studies are necessary to determine the clinical efficacy in patients with demodicosis.