Demodex Research Articles

Efficacy of a chewable tablet containing sarolaner, moxidectin and pyrantel for the treatment of generalised demodicosis in dogs.

Demodicosis is common in dogs and is caused by proliferation of commensal Demodex canis mites. To evaluate the efficacy of sarolaner in combination with moxidectin and pyrantel (SMP) for the treatment of generalised demodicosis in dogs. One hundred and thirty dogs with generalised demodicosis. In two separate randomised masked studies (laboratory and field studies), dogs received monthly oral SMP or afoxolaner + milbemycin oxime (AM). In the laboratory study, dogs received three monthly treatments with biweekly mite counts and clinical evaluations. In the field study, mite counts and clinical evaluations were performed monthly and treatments were administered until two consecutive skin scrapings were negative. Both products were tolerated well. In the laboratory study, mite counts for SMP were significantly (p < 0.001) reduced by 88.8% on Day (D)14, by 99.2% on D29, and no live mites were detected thereafter with no statistically significant difference (p = 0.96) between the two treatment groups. In the field study, SMP provided 92.4%, 98.1%, 100% and 100% reduction in arithmetic mean live mite counts on D30, D60, D90 and D120, and was non-inferior to the control product on D30 and D60. Clinical signs of demodicosis improved in all dogs. Monthly administration of SMP was effective for the treatment of generalised demodicosis in dogs as it eliminated Demodex mites after two monthly treatments in the laboratory study, and at most after three monthly treatments in the field study.

In vitro culture and morphological observation of human eye demodex mites

The prevalence of human Demodex mites has surged in recent years, prompting significant concern among both patients and the medical community. This study aimed to investigate the survival duration and morphological alterations of Demodex folliculorum under diverse temperature conditions and in various culture media. We employed the eyelash sampling technique to procure the mites. The collected specimens were then subjected to culture at two distinct temperature ranges (16–22 °C and 4 °C) across a spectrum of media, including 30% tea tree oil (TTO), phosphate-buffered saline (PBS), pure water, 0.9% physiological saline, 5 µg/ml propidium iodide (PI), liquid paraffin, glycerol, and a blank culture medium. Post-administration, the mites’ activity and morphological changes were meticulously documented. Our findings indicate that the survival span of Demodex mites within the same medium was notably extended at 4 °C compared to room temperature. Specifically, under 4 °C, the use of liquid paraffin as a culture medium yielded the longest survival time of 12 days, surpassing all other conditions. Remarkably, the morphological integrity of the mites in this group remained largely unaltered. These results suggest that 4 °C is the optimal temperature for the in vitro cultivation of Demodex mites, offering insights into the environmental preferences of these organisms and potentially informing future therapeutic strategies.

Multidisciplinary perspectives in Demodex blepharitis: A new view of treatment from clinical, payer, and patient perspectives.

Demodex infestation is the cause of more than two-thirds of all cases of blepharitis in the United States. Although symptoms may include crustiness, redness, or itching of the eyelids, diagnosis can be accomplished through a simple examination of the eyelashes. The presence of a waste product of the Demodex mite, known as collarettes, on the base of the eyelashes is a pathognomonic sign of Demodex blepharitis. Demodex infestation that results in blepharitis may cause blockage and ultimately atrophy of the meibomian glands, worsening dry eye disease. Until recently, management of Demodex blepharitis has been limited by a lack of approved therapy options. Lotilaner ophthalmic solution 0.25%, the first approved therapy for treatment of Demodex blepharitis, has not only been shown to eradicate Demodex mites in one-half to two-thirds of patients following short-term treatment but also demonstrated continued benefits through 1 year of follow-up. In addition to managing Demodex blepharitis, treatment with lotilaner ophthalmic solution 0.25% may aid in the management of dry eye disease and other forms of ocular surface disease caused by complications of Demodex infestation. As a result, it is possible that successful management of Demodex blepharitis may reduce chronic use of health care resources dedicated to managing other chronic ocular conditions. As eye care professionals recognize Demodex infestation as a key mediator of ocular surface disease, increasing diagnostic awareness and addressing this underlying cause of Demodex blepharitis may reduce the need for specialist follow-up care, decrease the need for chronic therapy, and improve patient outcomes. Through routine screening for Demodex infestation and Demodex blepharitis, eye care professionals can now address an underlying factor in ocular surface disease to improve use of health care resources in the community.

Evaluating the role of Demodex infestation and meibomian gland dysfunction in recurrent corneal erosion syndrome.

This investigation aims to observe the effects of demodex infection and meibomian gland function in recurrent corneal erosion syndrome (RCES), as well as the efficacy of intense pulsed light (IPL) in treating RCES. The study enrolled thirty patients diagnosed with RCES (30 eyes) alongside a control group of thirty-one individuals (31 eyes). Both cohorts underwent a series of diagnostic evaluations, including eyelash sampling, Demodex mite enumeration, infrared imaging of the meibomian glands, and blepharolipin scoring. The RCES subjects were further categorized into two subgroups upon stabilization for comparative analysis of treatment outcomes: the RCES-A subgroup received IPL therapy (16 patients), and the RCES-B subgroup was administered medication treatment (14 patients). Post-treatment, all participants were re-evaluated using the initial diagnostic procedures to monitor for recurrence. Preliminary findings indicated significant differences between the RCES and control groups in terms of meibomian gland scores (4 [3.0, 4.0] vs. 2 [1.0, 3.0]), blepharolipin scores (15.5 [11.0, 16.8] vs. 8.0 [5.5, 10.0]), and lid margin scores (3.0 [2.8, 3.0] vs. 2.0 [1.0, 3.0]), with P < 0.01 for all comparisons. Additionally, the Demodex count was significantly higher in the RCES group (8.0 [4.0,9.0]) compared to the control (0 [0, 2]) (Z = - 4.13, P = 0.00), with a Demodex positivity rate of 83.3% in the RCES group versus 38.7% in the control group (χ2 = 7.60, P < 0.01). Post-treatment, the RCES-A subgroup exhibited significant improvements in meibomian gland loss scores, blepharolipin scores, lid margin abnormality scores, and a reduction in Demodex counts (P < 0.01), with a post-treatment Demodex positivity rate of 56.3% (P = 0.11). During the follow-up, the RCES-A subgroup experienced a lower relapse rate compared to the RCES-B subgroup (1 vs. 6 patients). The findings suggest a correlation between meibomian gland dysfunction and Demodex infestation with the incidence of RCES. The application of IPL therapy in combination with meibomian gland massage demonstrates significant potential in enhancing meibomian gland functionality, reducing Demodex counts, and effectively mitigating the recurrence of RCES. Clinical trial registration: https://www.chictr.org.cn/ ChiCTR2000039494 (30/10/2020).

Efficacy of single-dose oral ivermectin in treatment of rosacea in relation to demodex mites

Background Rosacea is a common chronic inflammatory cutaneous disease. Demodex mites play an important role in the etiology and pathogenesis of rosacea. Despite the various therapeutic options available, rosacea can be difficult to treat in some patients. Topical Ivermectin is approved for the treatment of rosacea. However, oral Ivermectin has not been extensively studied in the treatment of rosacea. This study aimed to (a) evaluate the efficacy, safety, adverse effects, and patient satisfaction of a single 250 µg/kg dose of oral ivermectin in the treatment of different subtypes of rosacea and (b) correlate its efficacy to different clinical variables. Also, it aimed to (c) clarify the possible role played by demodex mites in the pathogenesis of rosacea and the effect of oral Ivermectin on demodex mite count change after treatment, and its possible mechanisms in the treatment of rosacea. Methods This study included 45 rosacea patients; demodex mite count using standardized skin surface biopsies was done before and after receiving a single dose of 250 µg/kg oral Ivermectin. Disease severity was assessed at baseline and after treatment using the 5-point Global Investigator Assessment IGA scale. Patients were followed up every 4 weeks for 3 months. Results The results revealed significant Global Investigator Assessment improvement in included patients and high patient satisfaction rate. This was consistent with Demodex mites count that showed a significant decrease after treatment. A low relapse rate and few side effects were recorded. Conclusion A single 250 µg/kg dose of oral ivermectin is effective, safe, and tolerable in the treatment of different subtypes of rosacea. It exerts its action through both anti-inflammatory and antiparasitic roles.

Detection and Eradication of a Demodex Infestation in Specific Pathogen-free High-barrier Laboratory Mouse Facility Housing Immunocompromised Animals.

Demodex mites are a common ectoparasite in nonlaboratory Mus musculus (mouse) populations. While infrequently reported in laboratory research mice, the prevalence is thought to be as high as 35% of all colonies. Here, we discuss an outbreak of Demodex within an SPF high-barrier vivarium housing laboratory mice first identified through commercial sentinel-free PCR testing. Consequently, in-house PCR-mediated identification of individually infected cages was conducted, and a successful method for eradication of secondary reemergent infection was generated via recurrent testing and empirical 12-wk treatment with 3 mg/kg moxidectin and 13 mg/kg imidacloprid. While we were unable to determine the source of our primary outbreak, the secondary outbreak was traced to nongenetically modified C57B6/J immunocompetent mice, which were capable of harboring subclinical infection below our PCR threshold. Our eventual successful eradication of Demodex confirmed, first, that in-house PCR detection is a cost-effective means of monitoring an outbreak; second, that treatment with 3 mg/kg moxidectin and 13 mg/kg imidacloprid does kill Demodex mites in laboratory mice; and third, that treatment of only PCR-positive mice is an insufficient way to control an outbreak. Taken together, our methodological approach for infestations such as Demodex suggests it is possible to eradicate them but that it requires a thorough, systematic, and aggressive treatment regimen. Moreover, we recommend that all cages derived from infected animals be treated as positive, regardless of PCR positivity, to prevent recurrent and/or persistent infections within an animal colony.

Identification and management of infections caused by Giardia sp., Trichuris sp. and Demodex sp. in captive Brazilian porcupines (Coendou prehensilis)

The Brazilian porcupine (Coendou prehensilis, Rodentia, Erethizontidae) is an arboreal South American nocturnal rodent. Switzerland is home to one of the largest captive colonies in Europe. In June 2022, most of the animals in this colony showed severe diarrhoea, and Giardia sp. cysts were detected. All the animals were treated with metronidazole (75 mg/animal/day orally) for five days, repeating after two weeks. The diarrhoea continued, sometimes containing blood, and further analyses revealed Giardia sp. cysts and Trichuris sp. eggs with a particular undulating eggshell in pooled samples. The soil layer of some enclosures was removed to thoroughly clean and disinfect the underlying concrete floor. The animals were treated with fenbendazole (50 mg/kg/day orally) for 5 days repeating after three days. Giardia sp. cysts were not further detected. However, Trichuris sp. eggs were detected in branch bark samples and in six animals 2–3 months after treatment. The treatment with fenbendazole was repeated and no further Trichuris sp. eggs were detected. A 18S rRNA fragment consensus sequence showed 98.58% identity with Trichuris fossor. The Trichuris sp. in C. prehensilis may represent a new species, specific for arboreal porcupines. Demodex mites were observed in faecal flotations and thereafter in skin scrapings from five animals (four of them being family-related). A 16S consensus sequence showed 86.4% identity with other Demodex species. The animals were initially treated with moxidectin (0.4 and 0.8 mg/kg orally) and afterwards with sarolaner (10 mg/animal) but the treatments were not completely effective since in control scrapings, two animals evidenced few non-motile mites. An individual susceptibility and poor immunological control of the infection is suggested. Treatment with fenbendazole was effective against Giardia sp. and Trichuris sp. infections; however, reinfections may occur if the enclosures and tree branches are not deep cleaned and disinfected or replaced.

Investigation of the in-vitro lethal effect of spilanthol on demodex and finding the most effective dose.

Demodex species are associated with many dermatological diseases, so an acaricidal agent that is effective against them and safe for skin applications may benefit many diseases. This study aims to investigate the anti-demodex potential of spilanthol, a product obtained from the Spilanthes Acmella plant, by determining the minimal effective dose for the first time in the literature. Demodex mites were obtained from 70 patients with standard superficial skin biopsy. Spilanthol extract was used at 1%, 2%, 3%, 4%, and 5%. Standard immersion oil was used for the negative control, and permethrin 5% was used for the positive control group. The dependent variable is the survival time of the mite. Comparisons with the negative control group, the anti-demodex effect demonstrated itself in all groups, creating a statistically significant difference (p < 0.001). The positive control group, had 3%, 4%, and 5% spilanthol rates which were very similar to the results with 5% permethrin (p > 0.05). Higher concentrations than 3% did not make any additional contribution to survival times. This is the first attempt to show the dose-dependent acaricidal effect of spilanthol on demodex mites. Even the 3% dose shows similar results to 5% permethrin, and no additional effect increase was observed at higher doses. Therefore, in vivo, studies may be planned with a 3% spilanthol dose for further studies.

Presence of Demodex spp. on the face and scalp in patients affected by papulopustular rosacea of face.

The increased proliferation of Demodex mites in the pilosebaceous unit can be the cause of rosacea flare-ups on the face. Signs and symptoms of the scalp (e.g., itching, dandruff) have sometimes been reported in patients with papulopustular rosacea of face; they may be due to a proliferation of Demodex mites on the scalp. To study the Demodex mites count, a standardized skin surface biopsy was performed on the cheek and on the scalp. Microscopic examination and molecular identification of Demodex were performed. Pearson's χ2 Test or Fisher's Exact Test were used to test for any association between categorical variables and outcome. Patients affected by papulopustular rosacea had a greater frequency of Demodex-positive standardized skin surface biopsy than controls at the scalp (35.0% vs. 0%, P=0.033), at the face and/or at the scalp (50% vs. 10%, P=0.032). Demodex positive patients with a Demodex-positive face sample were more frequently found to have a Demodex-positive scalp sample (P=0.035). The predominant species was found to be Demodex folliculorum (92.6% of samples); the species Demodex brevis was identified only in 7.4% of samples. Demodex folliculorum is more frequently found on the scalp and face of patients with rosacea than controls, even though it is not statistically associated with scalp symptoms. The scalp may be a reservoir area for Demodex mites which could migrate on the face again after an acaricidal treatment.

Lotilaner Ophthalmic Solution, 0.25%, for the Treatment of Demodex Blepharitis.

Demodex blepharitis, a chronic lid margin disease, is caused by an infestation of Demodex mites, the most common ectoparasites in human skin and eyelids. Lotilaner ophthalmic solution, 0.25% (Xdemvy, Tarsus Pharmaceuticals), is the first therapy approved to treat Demodex blepharitis. This narrative review characterizes lotilaner ophthalmic solution, 0.25%, and describes its efficacy, safety, and tolerability. The safety and efficacy of lotilaner ophthalmic solution, 0.25%, for treating Demodex blepharitis was evaluated in four phase 2 and two phase 3 trials. The data of 980 patients included in these phase 2 and 3 clinical trials revealed that the proportion of eyes with a clinically meaningful reduction to 10 or fewer collarettes (the cylindrical, waxy debris found at the base of the eyelashes) ranged from 81 to 93%. The mite eradication rate confirmed by a microscopy of epilated lashes ranged from 52 to 78%. No serious treatment-related adverse events were reported in any of these clinical studies. As high as 92% of the patients receiving lotilaner eyedrops in the phase 3 trials found it to be neutral to very comfortable. Given the positive safety and efficacy outcomes, the drug is likely to become the standard of care in the treatment of Demodex blepharitis.

Detection of demodex mites in papulopustular rosacea using microscopic examination and polymerase chain reaction: a comparative case-control study

Demodex mite proliferation is frequently involved in the pathogenesis of rosacea. The gold standard for Demodex identification is microscopic examination on a standardized skin surface biopsy. However, this method of sampling can be distressing and painful, especially when performed on hairy sites. In this case-control study, we compared the sensitivity of PCR and microscopic examination in diagnosing a Demodex infestation. Moreover, we investigated the possible correlations between the presence of Demodex mites and clinical characteristics. In total, 20 patients affected by papulopustular rosacea and 10 controls were included. At both microscopic examination and PCR, patients with rosacea presented a greater prevalence of positive samples than controls at the scalp and at the face. Microscopy had sensitivity of 50% at the face and of 46.7% at the scalp. PCR had sensitivity of 93.75% at the face and of 86.7% at the scalp. The positivity of PCR was associated to a higher frequency of facial papules and pustules. Patients with positivity at the face had a more frequent positivity at the scalp. The scalp could represent a reservoir for the Demodex mites, and should be investigated by sensitive and painless methods. PCR performed on painlessly collected samples should be further investigated.

Morphometry of Demodex species in dogs

The present study was carried out to record the mean length and width of gnathosoma, podosoma and opisthosoma of two different Demodex mites in dogs. The mean lengths gnathosoma, mean width of gnathosoma, podosoma and opisthosoma did not differ significantly (P&gt;0.05); mean length of podosoma, opisthosoma and the total body differed significantly (P&lt;0.05) between both types of mites of Demodex canis and Demodex cornei. The present study suggests that apart from examination of deep skin scrapings, tape impression smears may also be made a regular practice while dealing with demodicosis suspected dogs in order to detect the surface dweller like Demodex cornei

Management of pyoderma associated with demodicosis in a dog- A case report

Demodicosis is a very common parasitic skin disease caused by the mite Demodex canis. Demodecosis can occur in dogs of all ages. One-year-old adult male dog was presented with a history of pruritis and clinical signs such as alopecia, erythema and pustules on the face with keratinization of forelimbs and ventral side of the abdomen. Impression smear revealed Staphylococcus bacteria when stained with gram stain. Deep skin scrapping examination revealed presence of Demodex canis. Treatment with ivermectin, external application of amitraz, cephalexin, vitamin supplement with liver extract, was successful in managing demodicosis in this case.

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.

Role of Topical 5-Fluorouracil in Demodex -Associated Blepharitis.

The aim of this study was to report clinical observations suggesting the efficacy of topical 1% 5-fluorouracil (5-FU) in treating Demodex -associated blepharitis. An observational retrospective review of 13 eyes from 13 individuals with conjunctival neoplastic lesions and concomitant Demodex lash infestation that received topical 1% 5-FU eye drops. Patients underwent slit-lamp examination at each follow-up visit. Clinical photographs of the lash line were obtained after treatment initiation. In a subset of patients, lashes were epilated bilaterally and microscopically analyzed for presence of Demodex mites before and after treatment initiation. The mean age of the population was 68 ± 14 years (range: 30-84 years) and 92% were male. In all 13 patients, a marked reduction in cylindrical dandruff was noted in the treated eye by slit-lamp examination after 2 cycles of 5-FU. There was complete resolution of cylindrical dandruff in 10 of 13 treated eyes compared with 0 resolution of cylindrical dandruff in untreated eyes ( P = 0.0001). In the 6 patients who received epilation, the lashes from the treated eye showed no Demodex , whereas lashes from the fellow untreated eye revealed persistent Demodex . Topical 1% 5-FU shows efficacy in treating Demodex -associated blepharitis. Further studies are indicated to reproduce our findings and evaluate the potential use of 5-FU as a treatment ingredient.

Treatment With Topical Ivermectin 1% Once a Month to Control Demodex Blepharitis

Purpose: The study aimed to assess the effectiveness of a monthly application of topical 1% ivermectin cream, for 3 months, to the eyelids and eyelids margin, accompanied by gentle squeezing of meibomian glands and microexfoliation to the base of eyelashes, in the management of Demodex blepharitis. Methods: Thirty-eight patients diagnosed with Demodex blepharitis based on the presence of sleeves at the base of the eyelashes, telangiectasias, and signs of local inflammation with at least 4 Demodex mites observed at the lash roots were enrolled. Treatment involved applying 1% ivermectin topical cream using an eyelash brush in circular motion, gradually moving toward the eyelid margin. The procedure was repeated several times over 10 min by applying more cream. Each patient was evaluated before each treatment and 1 month after completion of the 3-month period. Results: Significant improvements in symptoms and signs were observed, with the disappearance of cylindrical sleeves on the base of the eyelashes, telangiectasias, signs of inflammation, and a significant decrease in night itching. The Schirmer test showed no changes, while the tear breakup time test exhibited slight yet statistically significant enhancement. No adverse events were reported during the study. Conclusions: The results of this investigation establish that Demodex blepharitis can be effectively managed by the application of 1% ivermectin cream once a month over a three-month period. This treatment approach, in conjunction with the gentle squeezing of meibomian glands and eyelid margin microexfoliation to the base of the eyelashes, resulted in the disappearance of objective indicators, such as cylindrical sleeves and telangiectasia, along with a significant reduction in nocturnal itching.

Which factors influence Demodex mite density in standardized superficial skin biopsy in patients with rosacea? A prospective cross-sectional analysis.

Rosacea is a chronic cutaneous disease that manifests with facial erythema, telangiectasia, papules and pustules on the central face. Although the pathogenesis is not well established, rosacea appears to have a close relationship with Demodex mites. The aim of the study was to elucidate the factors influencing Demodex mite density by standardized superficial skin biopsy (SSSB) in patients with rosacea. This prospective, cross-sectional study included 200 patients with rosacea. Clinical characteristics of the patients were recorded and SSSB was used to measure Demodex density (Dd). If Dd was < 5 D/cm2 in the first SSSB, SSSB was repeated 4 more times to avoid false negative results. Of 200 patients, 152 (76%) were females and 48 (24%) males with a mean age of 43.47 ± 11.87 years. Ninety-nine patients (49.5%) had erythematotelangiectatic (ETR) and 101 patients (50.5%) had papulopustular (PPR) subtype of rosacea. Among 200 patients, the ratio of cumulative positive results of the consecutive SSSBs were as follows: 1st SSSB = 125 (62.5%), 2nd SSSB = 155 (77.5%), 3rd SSSB = 170 (85%), 4th SSSB = 173 (86.5%) and 5th SSSB = 174 (87%). The ratio of detecting Demodex infestation in the first SSSB was significantly lower in patients with PPR (55/101, 54.5%) than in patients with ETR (70/99, 70.7%). Median total Demodex mite density and D. folliculorum density were significantly higher in the ETR group than in the PPR group. There was a statistically significant relationship between density of Demodex tails in dermoscopy and positive/negative results of Demodex infestation in SSSB. As a conclusion, Demodex mite density by SSSB was influenced by various factors such as subtypes of rosacea, types of Demodex species, and dermoscopic findings.

Human Demodex mites (Acari: Demodicidae) as a possible etiological factor in Rosacea: A cross-sectional study from Turkey

This study was conducted to determine the prevalence and burden of Demodex mites in patients with rosacea, and to investigate their potential contribution to the aetiology of rosacea. The study included 82 patients (44 with papulopustular rosacea and 38 with erythematotelangiectatic rosacea) diagnosed with rosacea by clinical examination and 82 healthy controls without dermatologic disease. Samples were obtained from each participant from the cheek, nasolabial, and chin regions using standardised skin surface biopsy (SSSB). Samples were examined under a light microscope, and Demodex species were identified and counted. Demodex positivity (≥5 mites) was detected in 91% of patients and 20% of controls in the study (p&lt; 0.01). Only D. folliculorum (total 1328, mean 44.27/cm2) was detected in 37% of patients and D. folliculorum + D. brevis coinfection (total 6071, mean 134.91/cm2) in 55% of patients. Only D. folliculorum (total 97, mean 6.06/cm2) was detected in 20% of healthy controls, while D. folliculorum + D. brevis co-infection was not detected. The study showed that Demodex burden in patients with rosacea was approximately 30 times higher than in healthy controls and was caused by coinfection of D. folliculorum and D. brevis (mean Demodex burden: 179.18/cm2 in patients, 6.06/cm2 in healthy controls). It was concluded that Demodex infestation, especially co-infection with D. folliculorum and D. brevis, may be a potential factor in the aetiology of rosacea that should not be ignored in the clinic, and that it may be appropriate to initiate antiparasitic treatment when the parasite is detected.

Evaluation of Demodex mite in chronic urticaria

Objective: Determining the possible role of Demodex mites in patients with chronic urticaria Methods: Demodex screening results in 49 patients with chronic urticaria were evaluated retrospectively. Results: The mean number of Demodex mites per 1 cm2 measured with standardized skin-surface biopsy (SSSB) was 0.89 which was at a similar level as control groups in the literature. Conclusion: Demodex mites seemed not to play a role in patients with chronic urticaria who had no facial eruptions. Patients with skin eruptions with the possible contribution of Demodex as rosacea could be investigated for chronic urticaria in other studies.

Data on Demodex Ectoparasite Infestation in Patients Attending an Outpatient Clinic in Greece

Demodex mites are acari, common ectoparasites of humans and other mammalian pilosebaceous units. Demodicosis occurs when mites overpopulate the skin, causing several skin disorders. Our aim was to investigate the prevalence of demodicosis in patients with suspicious clinical features, such as cheek redness, itching, and skin sensitivity, who presented at the outpatient clinic of the Andreas Syggros Dermatology Hospital in Greece. We studied 184 individuals aged between 18 and 97 years and analyzed the content of pilosebaceous units by microscopy to determine the density of Demodex mites. Samples were evaluated as positive when Demodex spp. densities equaled or exceeded 5 mites per square cm. Sixty-six percent of the examined subjects were positive for demodicosis. The age distribution was statistically normal (p = 0.2), and the median age was 51.29 years. Seventy percent of the patients were females, and 30% were males, while 64.46% of the demodicosis-positive individuals were females, and 35.54% were males. We observed a rise in the percentage of males as the age of the patients increased. Demodicosis can be a challenging disease because it presents apart from the typical symptoms, with a variety of nonspecific symptoms mimicking other dermatological skin conditions. Therefore, it is important to investigate Demodex spp. in patients who present with common facial dermatological diseases to improve treatment results. Further studies could contribute to a better understanding of the pathogenic role of Demodex mites and how this role is affected by mite density, host sex and age.