Demodicosis: update and treatment with laser and other light sources.

A novel application of Calcofluor White staining for high-contrast visualisation of demodex folliculorum and cylindrical dandruff under UV fluorescence microscopy.

Demodex mites inhabit the pilosebaceous unit despite harsh environmental conditions including UV radiation, variable salinity, and cosmetics. Their recently characterized endobacterium may contribute to this resilience. This study aimed to elucidate mechanisms of the microbe-host interaction that help mites withstand environmental stress. The genome of Corynebacterium kroppenstedtii subsp. demodicis was sequenced using PacBio technology and annotated via MicroScope. Metabolic and symbiotic traits were analyzed using KEGG and compared with the Demodex folliculorum secretome from published transcriptome data. The complete 2,456,075 bp genome contains 2034 coding sequences and exhibits reduced variable genes compared to other Corynebacterium species. Primary metabolism comprises an almost complete minimal gene set but lacks two tRNA synthetases and genes for phosphatidylethanolamine and NAD+ biosynthesis. Carbohydrate pathways are incomplete and fatty acid synthase I is absent. Secondary metabolism includes complete mevalonate and β-carotene biosynthetic pathways, while the methylerythritol phosphate pathway is missing. UV protection and oxidative stress tolerance are supported by β-carotene, ClpB, RecN, MsrA, KatA, SodA, and manganese transporter SitB. The secretome contains hydrolases likely aiding mite digestion. These findings provide genomic insights into mite-bacterium symbiosis and follicular adaptation. All functional inferences are based on genomic data and in silico predictions; experimental validation remains to be established.

Demodex blepharitis is aprevalent but often overlooked form of eyelid inflammation with significant impact on ocular surface health. Recent insights into the pathogenesis, especially the role of Demodex folliculorum and Demodex brevis, highlight its clinical relevance. The investigation and introduction of specifically efffective treatment approaches provide the prospect of expanded treatment options.

Demodex folliculorum infestation is an important contributor to meibomian gland dysfunction (MGD) and chronic ocular surface disease. This study evaluated and compared the therapeutic efficacy of intense pulsed light (IPL) and eyelid hygiene (ELH) for Demodex-associated MGD. In this prospective, randomized comparative trial, 50 patients (100 eyes) with Demodex-associated MGD were allocated to two arms. Group A (n = 25) received three Eyesis IPL sessions at baseline, week 2, and week 4. Group B (n = 25) performed daily eyelid hygiene with OCuSOFT Lid Scrub for 6 weeks. Ocular surface parameters, including ocular surface disease index (OSDI), tear film lipid layer thickness (TFLL), noninvasive tear film break-up time (NITBUT), meibomian gland dropout, meibum quality and expressibility, corneal fluorescein staining (CFS), Schirmer's I, and Demodex count, were assessed from baseline to week 6. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were recorded at each visit. Both treatments significantly improved OSDI, NITBUT, TFLL, Schirmer's I, and CFS over 6 weeks (all p < 0.001). Compared with ELH, IPL achieved larger and earlier reductions in symptoms, greater increases in TFLL, and superior improvements in meibum quality and expressibility from week 4 onward (between-group p ≤ 0.021). Demodex counts decreased significantly in both groups with no between-group difference at week 6. BCVA, IOP, and adverse events remained stable, indicating a favorable short-term safety profile. IPL and ELH are effective for Demodex-related MGD, but IPL provides faster and more pronounced improvements in meibomian gland function, tear film stability, and patient-reported symptoms over 6 weeks.

Demodex mites are believed to contribute to the pathogenesis of both rosacea and demodicosis. While standardized skin surface biopsy (SSSB) remains the gold standard for detecting Demodex density, it is invasive and time-consuming. Ultraviolet (UV) dermoscopy, a non-invasive technique that visualizes fluorescent structures, may offer a rapid alternative for identifying Demodex proliferation. To investigate the relationship between Demodex folliculorum (D. folliculorum) and Demodex brevis (D.brevis) counts obtained by SSSB and fluorescent dots detected under UV dermoscopy, and to evaluate the diagnostic value of these findings in rosacea and demodicosis. Fifty-four patients with rosacea or demodicosis were evaluated using both UV dermoscopy and SSSB from the same facial region. Orange and bright blue fluorescent dots were recorded dermoscopically, and mite density and species were quantified via SSSB. Correlation analyses and ROC curve analysis were performed to assess diagnostic performance. A significant positive correlation was found between total Demodex count and bright blue fluorescent dots (r = 0.343, p = 0.013), but not with orange dots (r = -0.065, p = 0.649). Only D. folliculorum showed significant correlation with blue and total fluorescent dots. ROC analysis identified >11 bright blue dots as the optimal threshold for predicting Demodex positivity, with a sensitivity of 82.1% and specificity of 71.4% (AUC = 0.793, p = 0.003). Bright blue fluorescent dots observed under UV dermoscopy significantly correlate with Demodex density, particularly D. folliculorum. A threshold of >11 blue dots demonstrated good diagnostic accuracy and may serve as a practical, non-invasive alternative or adjunct to SSSB in clinical settings. Orange fluorescence was not associated with Demodex density and likely reflects unrelated sebaceous or microbial activity.

Background: Demodex mite is the most common ectoparasite in humans. Demodex infestation or demodicosis often remains asymptomatic, but may be a significant causative agent for many dermatological and ophthalmological conditions. Demodex is found in all parts of the human skin, but the majority are on the face. Demodexbrevis inhabits the bottom of the sebaceous glands. Demodex folliculorum is found in the meibomian glands, eyebrows, and eyelashes, and can cause blepharitis. Both of them feed on oil for nutrition. Objectives: The main purpose of this cross-sectional descriptive research was to study the prevalence of human demodicosis and related risk factors in Ahvaz County, southwestern Iran (2022 - 2023). Methods: A total of 225 men and women referring to the Comprehensive Health Center in East Ahvaz were randomly and voluntarily selected. After completing the questionnaire, sampling from four areas of the face (nose, cheeks, chin, and forehead) was performed using the cellophane tape (CTP) and skin pressurization methods to determine Demodex infestation and evaluate associated risk factors. The results of this research were statistically analyzed using SPSS software version 13 and chi-square and Fisher’s exact tests at a confidence level of 95%. Results: According to the obtained data, Demodex infestation in the participants of the study was 52.7% in men and 47.3% in women, and the total detection rate of Demodex was 57.3%. The prevalence of demodicosis with methods CTP and skin pressurization was 53.8% and 18.2%, respectively. The difference in infestation rates between the two methods was significant. The highest and lowest infestation rates by facial area were in the nose (50.2%) and chin (6.2%), respectively, with a significant difference among facial regions. The study included participants over 20 years of age, with the highest infestation rate among those aged 51 and above (46.5%). A significant difference in infestation rates was observed across age groups. Conclusions: It was concluded that Demodex prevalence increases with age. The CTP is a good sampling method for investigations of demodicosis prevalence.

Humans mites Demodex folliculorum are found in the hair follicles and in pilosebaceous units, while D. brevis favours areas with high levels of sebaceous glands. Demodex mites present in excessive numbers can lead to demodicosis. The aim of the study was to investigate the incidence of Demodex mites infestation in patients and determine the effectiveness of selected aesthetic procedures in alleviating the consequences of chronic inflammation caused by the infestation. The study group consisted of 100 patients (81 women, 19 men), and Demodex infestation was noted in 44%. The patients infested with Demodex required anti-parasite therapy and post treatment observation. The most frequently-performed aesthetic treatments that improved skin condition and improved appearance were medical peelings, mesotherapy and botulinum toxin. In cases where Demodex spp. infestation has impaired the condition of the skin, supplementing antiparasitic treatments with Aesthetic Medicine can help achieve skin recovery, long-lasting aesthetic benefits and improve patient satisfaction.

Comparative in vitro efficacy of ivermectin, lotilaner, lime sulfur, tea tree oil, and lemongrass oil against Demodex folliculorum.

Microbe-Host Interaction in Rosacea and Its Modulation through Topical Ivermectin.

Demodex mites, particularly Demodex folliculorum and Demodex brevis, are common ectoparasites residing in human pilosebaceous units, often implicated in dermatological and ocular conditions such as rosacea, blepharitis, and demodicosis. Conventional treatments include topical acaricides such as ivermectin, permethrin, and metronidazole; however, these agents may be associated with limited efficacy, resistance, and adverse effects. Consequently, there has been growing scientific interest in exploring alternative therapies derived from natural sources, particularly essential oils and herbal extracts with known acaricidal, anti-inflammatory, and antimicrobial properties. The goal of this review was to investigate the effects of herbal extracts and essential oils on Demodex spp. Mites in skin and hair, as well as how these parasites operate and what impact they have on people's health. Demodex parasites are small arthropods that reside on the outer surface of the skin and often have no specific clinical symptoms. The main cause of disease in humans is two types of Demodex mites, Demodex folliculorum and brevis. Currently, chemical drugs that target Demodex usually have side effects and low efficacy. However, research has shown that plant extracts and essential oils such as tea tree oil have acceptable effects on the treatment of Demodex parasites and have fewer side effects. Therefore, applying these techniques may be a more suitable choice for treating demodicosis.

Rosacea is a chronic inflammatory skin disease affecting approximately 5.4% of the world population. Among its pathogenic factors is infestation by Demodex spp. Standardized skin surface biopsy (SSSB) and direct microscopic examination (DME) are widely used methods to measure Demodex spp density (Dd); however, there is no agreement on the method of choice, nor the prevalence of infestation in rosacea patients. This study compared both techniques in rosacea patients. A prospective study was conducted with 61 patients diagnosed with rosacea by dermatologists from two dermatology centres. Dd was evaluated using SSSB and DME in each patient. Results, median sampling time and reported pain were analyzed using appropriate statistical methods. The median Dd was significantly higher with SSSB (11 mites/cm2) compared to DME (1 mites/cm2; P < 0.001). Infestation (>5 mites/cm2) was detected in 64% of patients with SSSB and in 28% with DME (P < 0.001). The median sampling time was longer for SSSB (60 s) than for DME (30 s; P < 0.001). Both methods were associated with mild pain, slightly lower with DME (P = 0.033). SSSB proved more effective than DME for detecting Demodex spp. in rosacea, identifying a greater total number of mites and a higher percentage of infestation. Up to 64% of rosacea patients showed infestation with Demodex spp. using the SSSB technique. The results reinforce the use of SSSB as the standard technique for diagnosing Demodex spp. infestation in rosacea patients.

Demodex eyelash mites are increasingly associated with eye and skin inflammation in humans, and cause demodectic mange in mammals. Informal accounts of symptom improvement and reduced need for anti-allergy medicines, when Demodex reproduction is prevented, indicate a further role linking Demodex to rhinitis, asthma and dermatitis. Their mobility, allergenic debris and consequential immunological impact may also explain progression of allergies in the “allergic march”. Being photophobic and nocturnal, Demodex folliculorum shelter, feed, and sleep in eyelash follicles during daylight. Coston (1967) speculated that Demodex emerge to mate during darkness and observed that medicated ointments rubbed into the eyelid margins at bedtime treated Demodex blepharitis effectively, presumably by preventing mating. Sixteen cases are described retrospectively whereby interested volunteers adopted Coston's technique, using unmedicated petroleum jelly. To break the lifecycle, a minimum 28-day course was advised, though concordance varied. Fourteen people reported relief from a surprising range of symptoms including not only dry eye and blepharitis but also rhinitis, asthma, angioedema and seborrhoeic dermatitis. Analysis of GP prescribing data in three volunteers allowed comparison of five-year periods immediately before and after starting continuous treatment. Mean yearly issues of anti-allergy and antimicrobial medicines reduced from 15.6 (range 8–25) to 1.8 (range 0–4), representing an 88.5% decrease for Volunteer 1 and from 5.8 (range 3–9) and 14.2 issues (range 9–24) to zero for both Volunteer 2 and Volunteer 13 respectively, representing 100% reductions in prescribing. Exacerbations of acne and dermatitis in two cases illustrate possible Demodex involvement in common dermatoses. This account is limited by its informal and retrospective nature in a disparate cohort, without assessment of Demodex levels. These preliminary observations support the hypothesis that Demodex allergens may trigger facial, ocular and respiratory inflammation and that reducing mite count with petroleum jelly improves symptoms. Formal clinical trials are needed to test this hypothesis.

Rosacea is a chronic inflammatory skin condition of the central face driven by immune dysregulation, genetic predisposition, epidermal barrier dysfunction, and microbial dysbiosis. Recent evidence implicates both the gut and skin microbiomes-through direct immune interactions and the gut-skin axis-in driving cutaneous inflammation and disease severity, with an increase in proinflammatory species such as Demodex folliculorum, Staphylococcus epidermidis, and Bacillus oleronius alongside a decline in protective species such as Cutibacterium acnes. Therapeutic strategies now aim to restore microbial balance using narrow-spectrum antibiotics, anthelmintics, topical and oral probiotics, and microbiome-friendly skin care to reduce inflammation, reinforce skin barrier function, and improve clinical outcomes. Future research to refine precision treatments that target specific microbial and immune pathways would be beneficial to modulate dysbiosis and improve outcomes in rosacea.

ABSTRACT Clinical relevance The multifactorial aspect of dry eye disease remains challenging. Demodex folliculorum, a common ectoparasite on human eyelashes, may impact eye conditions such as blepharitis which can be a contributor to dry eye disease. Exploring risk factors for Demodex helps to raise awareness for early detection potentially improving ocular health. Background Demodex folliculorum found on eyelashes can cause blepharitis. Its gelatinous debris at the base of the lashes, termed cylindrical dandruff is often associated with ocular itching. This study examined the prevalence of Demodex in a University population and assessed its relationship to symptoms of dry eye and itching. Methods Visual acuity, dry eye questionnaire (OSDI), non-invasive break up time (NIBUT), meibography, and slit-lamp examination were measured. When cylindrical dandruff was observed, lateral tension was exerted on two eyelashes to identify Demodex tails. Mann–Whitney tests were applied for comparisons, logistic regressions were applied to determine relationships, and chi-square, Fisher’s exact test and Spearman correlation tests determined associations. Results Of the 101 participants (mean age: 28 ± 12, range: 19–68 years, 90 females), 20% had dry eye (OSDI score ≥ 13 and NIBUT < 10 sec). Demodex tails/lash were significantly more prevalent in the upper (44%) compared with the lower eyelids (19%). Anterior blepharitis and cylindrical dandruff were significantly correlated with Demodex. Ocular itching (prevalence: 39%) was significantly associated with presence of Demodex only for the upper eyelids (p = 0.02). UODS was positively correlated (p < 0.001) with Demodex, cylindrical dandruff and anterior blepharitis. Conclusions There was a relatively high prevalence of Demodex among a university population. The prevalence of Demodex was not significantly different in those diagnosed with dry eye. Cylindrical dandruff and anterior blepharitis were significantly associated with the presence of Demodex, while itching was associated with presence of Demodex only for the upper eyelids. The UODS can be a valuable tool to add in future Demodex studies.

Abstract Karl Gustav Theodor Simon (1810–1857) was a pioneering pathologist and dermatologist who is widely regarded as the ‘father of dermatopathology’. Simon commenced his medical studies in his home city of Berlin in 1829, where he also defended his doctoral thesis studying the styptic properties of Binelli’s water and creosote. After graduating, Simon began his career as a private physician while pursuing research interests in the pathology of cutaneous diseases. Using early anatomopathological techniques, Simon was able to examine, describe and classify various skin conditions, resulting in several scientific discoveries. In 1842, for example, while studying skin specimens from a patient with acne vulgaris, Simon noticed unusual movements within the sample. Upon closer inspection, he was astonished to discover that the source of this movement had a ‘head, legs, fore and hind body’. This observation led Simon to publish the first detailed description of the Demodex folliculorum mite, which he eponymously named ‘Simonea folliculorum’ {Simon KGT. [On a mite living in the diseased and normal hair follicles of humans]. Arch Anat Physiol Wissensch Med 1842; 218–37 (in German)}. Simon’s growing reputation earned him a position as a private lecturer at the Friedrich Wilhelm University of Berlin in 1844, where he taught general anatomy, pathology and dermatology. In 1848, he advanced to Director of the Department for Skin Diseases and Syphilis at the Charité Hospital in Berlin. It was during this period that he achieved his most significant milestone: authoring the first textbook on dermatopathology, ‘Die Hautkrankheiten durch anatomische Untersuchungen erläutert’ (Skin Diseases Clarified by Anatomic Studies). This seminal work established the fundamental principles for correlating clinical dermatological findings with microscopic observations and provided the first detailed histopathological descriptions of various skin diseases. Simon continued to serve as Director of the Charité Clinic until his health deteriorated due to progressive neurosyphilis, which ultimately ended his career. He passed away in 1857 at the age of 47 years. Despite his untimely death, Simon’s pioneering efforts defined dermatopathology as a distinct discipline and solidified histopathology as an essential tool in dermatology – a cornerstone of clinical practice to this day. His work remains a vital historical reference, with translations continuing to provide insight into the evolution of dermatopathology over the past two centuries.

Objectives: Demodicosis results from the overgrowth of Demodex mites, Demodex folliculorum, and Demodex brevis, which are normally present on human skin. Overpopulation of these mites can cause skin manifestations ranging from erythema and scaling to papules, pustules, and nodules, mimicking other dermatoses such as rosacea and seborrheic dermatitis. This study was planned to assess the clinical and dermoscopic features of patients with demodicosis by retrospectively analyzing cases suspected and confirmed of having the condition. Materials and Methods: A retrospective analysis was conducted on clinically suspected demodicosis cases from January to December 2023, using standardized skin surface biopsies to quantify Demodex mites. Patient data, including age, gender, disease duration, lesion morphology, comorbidities, and topical corticosteroid use, were collected from records. Dermoscopic images retrieved from the database were analyzed. Results: Of the 25 suspected cases, 11 tested positive on standardized skin surface biopsy, with a mean age of 27.4 years. The clinical spectrum included cases of sensitive skin (2), pityriasis folliculorum (3), perioral/orbital dermatitis (3), papulopustular demodicosis (2), and nodulocystic demodicosis (1). Six patients had a history of corticosteroid abuse. Dermoscopy findings included Demodex tails (63.6%) and Demodex follicular openings (72.7%). Patients with primary demodicosis showed a significant improvement with topical ivermectin monotherapy. Limitations: Limitations of the study are its retrospective nature and small sample size. Conclusion: Demodicosis should be considered in cases of facial skin lesions, particularly with a history of corticosteroid use. The addition of dermoscopy can significantly aid in the correct diagnosis of demodicosis. Proper diagnosis and treatment, including acaricides like ivermectin, can significantly improve patient outcomes.

Pruritic papular eruption (PPE) is a chronic, intensely itchy skin condition commonly seen in people living with HIV (PLH). While PPE is well documented in regions with high HIV prevalence, its clinical presentation, risk factors, and treatment strategies in the United States remain poorly characterized. Thus, this study aims to fill critical gaps in understanding PPE among PLH in the United States by investigating its epidemiology, clinical features, and risk factors. A comprehensive literature search across PubMed, Google Scholar, and Cochrane identified 8 papers documenting 11 patients with PPE. Our results showed that the most commonly affected areas included the arms (82%), chest (45%), back (45%), face (36%), neck (36%), and anal cleft (18%). Seven patients (64%) had a concurrent bacterial or fungal infection with Candida albicans (42.9%) and Treponema pallidum (42.9%). Candida lesions were most commonly seen in the oral mucosa and inguinal or anal clefts. Overgrowth of commensal organisms such as Demodex folliculorum was also noted in or around the pilosebaceous units for 28.6% of patients. The most common treatment strategies include antiretroviral therapy and adjuvant corticosteroid or ultraviolet B phototherapy which helped relieve the pruritis associated with papulonodular lesions. These findings highlight how PPE may serve as a marker for severe immunosuppression among PLH. In HIV patients who present with a rapid onset of pruritic lesions, PPE should be a key consideration in the differential diagnosis. In these patients, thorough physical examination and further diagnostic evaluation for potentially associated infections is warranted.

Herein, we present scanning electron microscopy imagery of Demodex folliculorum on the eyelashes of a patient with a two-year history of dry, burning, and watery eyes. Demodex mites are part of the normal human skin flora, inhabiting hair follicles and sebaceous glands. However, in some individuals, they may contribute to ocular surface diseases, including blepharitis and dry eye disease. Symptoms often include itching, photophobia, and a foreign body sensation. The pathogenic role of Demodex is not fully understood but may involve microabrasions, gland obstruction, hypersensitivity reactions, and bacterial dysbiosis. The presence of collarettes at the base of eyelashes is a diagnostic hallmark. Although optimal treatment remains debated, options include topical tea tree oil, ivermectin, and a recently FDA-approved drug lotilaner. Our patient responded favorably to a two-month regimen of tea tree oil-based eyelid wipes. This case underscores the clinical relevance of Demodex infestation in chronic ocular discomfort and highlights the importance of diagnostics.

Demodex species in the family Demodicidae are hair follicle scabies agents. Demodex species are transmitted from person to person through close contact, shared towels, make-up materials, etc. This study was conducted to obtain data on the relationship between mandatory mask use and demodicosis during the Coronavirus disease-2019 (COVID-19) period. The study included 510 students who used masks in necessary environments since the beginning of the pandemic and participated in the study voluntarily. Cellophane tapes were applied to the relevant areas three times. In addition, both eye lashes were pulled from both eyes and adhered to the cellophane tapes. The samples were examined under light microscope at different magnifications (x10, x40). Demodex folliculorum and Demodex brevis were detected in 38 (7.5%) of 510 students. D. folliculorum was detected in 33 of the positive students and both D. folliculorum and D. brevis were detected in 5 students, 2 of whom were male and 3 of whom were female. Demodex spp. was found in 12 (4.9%) of 245 students who answered "no" to the question "Do you have acne or skin complaints on your face?" and in 26 (9.8%) of 265 students who answered "yes". While this parameter was statistically significant, the other parameters were not statistically significant. The COVID-19 period has changed people's lifestyles and habits in many ways. It has made the use of masks obligatory. During mandatory mask use, factors that may increase the presence of Demodex spp. should not be ignored.