The association of demodex infestation with pediatric chalazia

Global Prevalence of Human Demodex Mite: A Systematic Review and Meta-Analysis

Demodex mites are common ectoparasites in humans that typically reside as commensals in sebaceous glands, but under certain host conditions, they may become opportunistic pathogens. Despite numerous localized studies on the prevalence of human Demodex mites, the global prevalence and associated risk factors remain unclear. This study aims to systematically assess the global prevalence of human Demodex mites and the effects of age, gender, facial sampling region, humidity, World Health Organization (WHO) regions and countries, and population factors on this prevalence. A systematic literature search, following PRISMA guidelines, was conducted in multiple databases from January 2000 to January 2025. Meta-analysis using a random-effects model estimated the global prevalence of Demodex mites and examined associations with demographic, geographic, and climatic factors. Meta-regression, sensitivity analysis, and Egger's test were conducted to assess publication bias and the robustness of the findings. The global pooled prevalence of human Demodex mites was approximately 35% (based on available studies), with the highest prevalence observed in the South-East Asia Region (SEARO) at 44%. The highest prevalence among age groups was found in older adults (>60 years), reaching 59%, while the highest facial region-specific prevalence was observed in the eyelashes at 33%. Among different population groups, ophthalmology patients showed the highest prevalence (57%). Additionally, the prevalence was slightly higher in females compared to males. The analysis revealed significant heterogeneity and publication bias. The sensitivity analysis confirmed the stability of the prevalence estimate. Meta-regression identified significant differences in sample size but no associations with humidity or publication year. This meta-analysis highlights a global prevalence of human Demodex mites, especially among older adults and ophthalmology patients, emphasizing the need for clinical awareness and further studies.

Demodex and the eye - A review

Demodexblepharitis (DB) has become one of the common differential diagnoses in patients presenting with red eyes in daily clinics. In this review article, we have incorporated a detailed discussion about the mite and the various mechanisms by which it causes different signs and symptoms, the risk factors, and diagnostic methods with current and emerging treatment modalities. Because of the chronic symptoms and rather a late diagnosis, DB considerably affects patients' quality of life. The clues to identify cylindrical dandruff, the diagnostic sign of Demodex, visualization of the mite correlating their presence with signs and symptoms, and instituting early and appropriate treatment are the goals of this article.

Therapeutic effect of intense pulsed light on different types of chalazion in children

This study aims to investigate the effectiveness of Intense Pulsed Light (IPL) therapy for chalazion treatment while also exploring potential variations in sensitivity among different types of chalazion. A total of 149 patients were selected to receive tobramycin combined with IPL treatment and tobramycin combined with hot compress. The treatment groups were divided into cystic type and granulomatous type according to different clinical manifestations. The course of treatment was 3 weeks. The improvement was based on the ultrasound measurement of the masses reduction of more than 50% or disappearance. In the IPL group, 17 (22.67%) cases were cured, 39 (52.00%) were effective, and 19 (25.33%) were ineffective. This includes: cystic type was cured in 3 (15.79%), effective in 5 (26.32%) cases, ineffective in 11 (57.89%) cases; granulomatous type was cured in 14 (25.00%) cases, effective in 34 (60.71%) cases, ineffective in 8 (14.29%) cases. In the hot compress group, 5 (6.76%) cases were cured, 16 (21.62%) cases were effective and 53 (71.62%) cases were ineffective. The cystic type was cured in 2 (8.00%) cases, effective in 3 (12.00%) cases and ineffective in 20 (80.00%) cases; the granulomatous type was cured in 3 (6.12%) cases, effective in 13 (26.53%) cases and ineffective in 33 (67.35%) cases. The cure rate and efficacy rate of IPL treatment is higher than that of hot compress treatment, the treatment effect of IPL treatment on granulomatous chalazion is better than that on cystic type.

High Load of Demodex in Young Children With Chalazia

PURPOSE

To investigate the correlation between demodicosis and pediatric chalazia.

METHODS

A case-control prospective study was conducted at Children's Hospital of Fudan University between December 2018 and January 2019. One hundred one consecutive pediatric patients with chalazia and 42 pediatric patients without chalazia underwent eyelash sampling and Demodex examination using light microscopy, and mite presence and count were documented.

RESULTS

The Demodex count and prevalence of the chalazia group was much higher than that of the control group (3.06 ± 3.48 vs 0.64 ± 1.17; P ≤ .001; 73.3% vs 35.7%, P ≤ .001). The Demodex count and prevalence of the multiple chalazia subgroup was much higher than that of the single chalazion subgroup (3.49 ± 3.72 vs 2.00 ± 2.52; P = .043; 79.2% vs 58.6%, P = .035). The Demodex count and prevalence of the chalazia with skin erosion subgroup was much higher than that of the without skin erosion subgroup (3.54 ± 3.14 vs 2.55 ± 3.76; P = .012; 82.7% vs 63.3%, P = .027). After adjustment for age and gender, Demodex count (odds ratio: 1.873; 95% confidence interval: 1.155 to 3.040; P = .011) but not presence (P = .643) was significantly correlated with chalazia.

CONCLUSIONS

Demodex mites were more prevalent and quantitative in children with chalazia, and children with severe chalazia had higher Demodex prevalence and quantity. High Demodex count rather than presence of it was associated with chalazia. [J Pediatr Ophthalmol Strabismus. 2023;60(5):365-371.].

Demodex Blepharitis: A Comprehensive Review of the Disease, Current Management, and Emerging Therapies

ABSTRACT

Demodex blepharitis is a common disease of the eyelid, affecting approximately 25 million Americans. This article reviews what is known about the mechanisms and impact of Demodex blepharitis, risk factors, signs and symptoms, diagnostic techniques, current management options, and emerging treatments. Demodex mites contribute to blepharitis in several ways: direct mechanical damage, as a vector for bacteria, and by inducing hypersensitivity and inflammation. Risk factors for Demodex blepharitis include increasing age, rosacea, and diabetes. The costs, symptom burden, and psychosocial effects of Demodex blepharitis are considerable. The presence of collarettes is pathognomonic for Demodex blepharitis. Redness, dryness, discomfort, foreign body sensation, lash anomalies, and itching are also hallmarks of the disease. Although a number of oral, topical, eyelid hygiene and device-based options have been used clinically and evaluated in studies for the management of Demodex blepharitis, none have been FDA approved to treat the disease. Recent randomized controlled clinical trials suggest that lotilaner ophthalmic solution, 0.25%, is a topical treatment with the potential to eradicate Demodex mites and eliminate collarettes and eyelid redness for an extended period.

Refining the Diagnostic Technique to Determine Prevalence of Demodex Mites in Eyelash Hair Follicles Within Standard Ophthalmic Practice: A Single-Center Outpatient Clinical Study

Purpose

A high density of Demodex infestation in human eyelids and eyelash follicles has been implicated in a variety of ocular surface conditions. However, Demodex infestation often goes undiagnosed and untreated, due to an overlap in signs and symptoms with other sources of ocular surface inflammation. We sought to refine the diagnostic technique for outpatient assessment for Demodex infestation and determine prevalence of Demodex mites in the hair follicles of eyelashes from patients in a standard ophthalmic practice.

Patients and Methods

Patients recruited from a single outpatient ophthalmology clinic were examined for the presence of Demodex mites following standard ophthalmic consultation. During anterior segment biomicroscopic examination, investigators searched for cylindrical dandruff and collarettes around the base of patient eyelashes. These were removed, and individual eyelashes manipulated with tweezers to reveal Demodex mites. Presence of Demodex, cylindrical dandruff and collarettes, time taken to identify the first Demodex mite, mean number of Demodex mites per hair shaft, and patient-reported symptoms of blepharitis were recorded and analyzed to determine potential correlations.

Results

A total of 173 patients were recruited, of whom 106 were included in Demodex prevalence analyses. Demodex infestation was identified in 100/106 (94%) patients, with a mean time of 2 minutes and 20 seconds taken to find the first Demodex mite and a mean number of 3 mites identified per hair shaft. Presence of Demodex significantly correlated with the presence of cylindrical dandruff (98/106 [92%] patients; p < 0.001), but not with the presence of collarettes (62/106 [58%] patients; p = 0.230) or symptoms of blepharitis (15/106 [14%] patients; p = 0.591).

Conclusion

These results highlight the pervasiveness of Demodex infestation, predicted by the presence of cylindrical dandruff, in the eyelashes of patients in a standard ophthalmic practice. They support the use of a non-invasive diagnostic technique to allow fast, simple identification of Demodex by ophthalmologists and optometrists in outpatient clinical practice.

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.