Skin Surface Biopsy Research Articles

Efficacy of Oral Ivermectin in Treatment of Rosacea

Abstract Introduction Rosacea is a chronic inflammatory dermatosis involving certain facial areas such as chin, nose, forehead, and cheeks. Several therapies were reported in the treatment of rosacea but with variable results. Aim of the Study To evaluate the efficacy, safety, adverse effects, relapse rate and patient’s satisfaction of single 250μg/kg dose of oral ivermectin in the treatment of rosacea. Patients and Methods This clinical trial included 45 rosacea patients who were treated with single 250μg/kg dose of oral ivermectin, then patients were followed-up every 4 weeks for 3 months. Assessment of treatment response was performed using 2 digital photographs before receiving ivermectin and 3 months later. Two Standardized skin surface biopsies (SSSB1&2) were done before receiving ivermectin and 3 months later. Results Ivermectin treatment revealed significant effect in included patients as 15 patients showed clear effect of rosacea after treatment. This was consistent with Demodex mites count that showed significant decrease after treatment compared to before treatment. There was a significant relation between patients’ satisfaction and demodex mite count after treatment Conclusion Oral ivermectin showed significant clearing of rosacea in included patients which was reflected on patients’ satisfaction. This effect can be attributed to significant reduction in demodex mite count in treated patients.

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.

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.

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.

Randomised, split-face study of a dermocosmetic cream containing Sphingobioma xenophaga extract and Neurosensine® in subjects with rosacea associated with erythema and sensitive skin.

Rosacea is a chronic inflammatory skin condition associated with erythema, inflammation and skin sensitivity. To assess the benefit of a dermocosmetic cream (DC cream) containing Sphingobioma xenophaga extract and soothing agent in adult females with rosacea-associated erythema and sensitive skin. During phase 1, DC was applied twice daily on the randomized half-face and compared to usual-skincare (USC) for 28 days. During phase 2, DC was applied on the full face twice daily for 56 days. Clinical, instrumental and skin sensitivity assessments were performed at all visits; demodex density (standardized skin surface biopsy (SSSB) method) was performed at baseline and D28, quality of life (QoL) was assessed using the stigmatization questionnaire (SQ), Rosacea Quality of Life index (ROSAQoL) and Dermatology Life Quality Index (DLQI) at baseline and D84. At D28, a significant benefit of DC over USC was observed for erythema, tightness, burning and stinging (all p≤0.05), erythema measured by chromameter (p<0.01), corneometry and transepidermal water loss (p<0.0001 and p<0.05, respectively), skin sensitivity (p<0.001) and significant reduction of mean demodex density (p<0.05) on the DC side. At D84, DC significantly (all p<0.05) improved clinical signs and symptoms on both sides of the face compared to baseline; SQ, ROSAQoL and DLQI scores improved by 40.4%, 25.0% and 55.7%, respectively compared to baseline. Tolerance was excellent. DC significantly improved erythema, skin sensitivity, demodex count, QoL and feeling of stigmatization of subjects with rosacea and is very well tolerated.

Demodex folliculorum (Trombidiformes: Demodecidae) infestation in medical students with facial dermatoses and healthy groups.

Demodex folliculorum (Simon, 1842) has been associated with various dermatological conditions. This study aimed to assess the prevalence of Demodex infestation in medical students with facial dermatoses compared with healthy medical students serving as controls. A total of 250 participants were enrolled, including 150 individuals with facial dermatoses and 100 healthy controls. Sampling was performed based on the standardized skin surface biopsy method. Demographic characteristics, specifically gender and age, were not statistically different between the patient and control groups. Among the facial dermatosis patients, 25 out of 150 (16.6%) were found to have Demodex infestation, while only three out of the 100 healthy controls (3%) exhibited infestations. The only identified species was D. folliculorum. The rates of Demodex infestation were significantly higher in the patients compared to the control groups. These findings indicate a higher prevalence of Demodex infestation among medical students with facial dermatosis, particularly in those diagnosed with folliculitis, acne vulgaris, and inflammatory papule, when compared to healthy controls. A better understanding of the relationship between D. folliculorum infestation and these dermatological conditions may lead to improved diagnostic and treatment strategies in the future.

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.

Biologic therapy increases Demodex density in psoriasis patients.

Demodex density is known to increase in various immunosuppressive conditions. The relationship between biologic therapy and Demodex density remains unknown. We aimed to investigate whether the density of Demodex mites is higher in psoriasis patients treated with biologic agents compared to treatment-naive or topically treated patients. A cross-sectional study was conducted, comparing psoriasis patients receiving biologic therapy (n = 34) with controls (n = 33). Demodex density was assessed using the standardized skin surface biopsy technique (SSSB). Statistical analysis was performed to compare the densities and prevalence of demodicosis between the two groups. Demodex density was significantly higher in the biologic therapy group compared to the control group on the right cheek (7.29 vs. 0.12/cm2; P = 0.001), left cheek (8.15 vs. 0.24/cm2; P = 0.002), and whole face (average of all four regions: 5.50 vs. 0.80/cm2; P = 0.001). The prevalence of demodicosis was significantly higher in the biologic therapy group on the forehead (35.3% vs. 12.1%; P = 0.043), right cheek (41.2% vs. 0%; P < 0.001), and left cheek (44.1% vs. 0%; P < 0.001). The frequency of cases with demodicosis in at least one localization was higher in the biological therapy group compared to the control group (61.8% vs. 15.2%; P < 0.001). Psoriasis patients receiving biologic therapy had a higher Demodex density and prevalence of demodicosis compared to controls. Biologics may lead to an increase in Demodex density by blocking specific cytokines, such as interleukin-17 and tumor necrosis factor-α, which play a role in immunity against Demodex. Further research is needed to explore the impact of different biological agents on Demodex density.

The effect of phototherapy on Demodex density: acase-control study.

Human Demodex mites, Demodex folliculorum and Demodex brevis, are microorganisms that reside in the pilosebaceous units, usually without causing symptoms. Phototherapy has been linked to demodicosis in previous studies. We aimed to determine whether there was an increase in the frequency of demodicosis and Demodex density after 20 phototherapy sessions. A case-control study was conducted with 32 participants who received narrowband ultraviolet B or ultraviolet A-1 therapy for various dermatological indications. Standardized skin surface biopsies were performed before and after phototherapy to assess Demodex density. The presence of Demodex-related skin conditions was assessed before phototherapy. A statistical analysis was performed to compare the Demodex densities and prevalence of demodicosis between the baseline and 20th session of phototherapy. No significant change was observed in Demodex density after 20 sessions of phototherapy. The average Demodex density before treatment was 2.75 ± 4.48 (/cm2 ), and after treatment, it was 2.85 ± 4.81 (/cm2 ), indicating no significant difference (P = 0.879). The percentage of patients with demodicosis in at least one region of the face was 28.1% (9/32) before treatment, and after treatment, it was 31.3% (10/32), with no significant difference (P = 1.00). Our findings contradict previous studies that suggested an increased Demodex density and demodicosis prevalence after phototherapy. The data from previous studies are open to debate due to their selected samples, designs, and interpretations regarding the phototherapy-immunosuppression-Demodex relationship. Larger-scale longitudinal studies conducted on a homogeneous sample are warranted to better understand the relationship between phototherapy and demodicosis.

Has the Use of the Mask Exacerbated Rosacea During the Pandemic?

During the COVID-19 pandemic, personal protective equipment, particularly face masks, became an essential requirement to engage in various activities. Several articles reported an increase of recurrences of dermatologic facial diseases (ie, acne, rosacea) related to mask use. To evaluate the number of recurrences of rosacea related to face mask use. This prospective study was conducted on adult patients with a pre-pandemic diagnosis of mild and moderate papulopustular rosacea. All patients had previously achieved either partial or complete remission after a 4-month treatment with topical ivermectin in 2019. We collected data in two different phases characterized by different intensity of mask use during the pandemic and post-pandemic period. We collected data through clinical assessment of the disease, questionnaires on personal habits and standardized skin surface biopsy to study the Demodex mites count. We enrolled a total of 30 patients. In the pandemic period, 5/30 patients had a relapse of mild papulopustular rosacea; the Demodex sample resulted positive in 4/5 relapsed patients. In the post-pandemic period, 4/30 patients reported a relapse of mild rosacea (3 patients) and moderate papulopustular rosacea (1 patient). At the Demodex exam, 1/4 relapsed patients resulted positive. We did not find a significant increase in relapses of papulopustular rosacea during the pandemic. An appropriate anti-parasitic treatment may reduce the number of recurrences due to mask use.

Characteristics of Biofilm-Forming Ability and Antibiotic Resistance of Cutibacterium acnes and Staphylococcus epidermidis from Acne Vulgaris Patients.

Acne vulgaris (AV) is a common and chronic disorder of the pilosebaceous unit and has a multifactorial pathology, including activities of Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis). Antibiotic resistance has become a major concern in dermatology daily practice, and the ability of biofilm formation by both bacteria is suggested to increase antibiotic resistance in acne. Our aim was to analyze the comparison of antibiotic resistance between biofilm-forming (BF) and non-biofilm-forming (NBF) strains of C. acnes and S. epidermidis towards seven antibiotics commonly used for acne. This is a cross-sectional analytical study involving 60 patients with AV. Samples were obtained from closed comedones on the forehead using the standardized skin surface biopsy (SSSB) method at the Cosmetic Dermatology Clinic Dr. Hasan Sadikin in Bandung, Indonesia. Isolates were cultured and identified before undergoing the biofilm-forming test using the tissue culture plate method. Antibiotic susceptibility testing for each antibiotic was then performed using the disc diffusion method. The incidence of antibiotic resistance to clindamycin in BF and NBF C. acnes isolates was 54.5% (p=1.00), while in BF and NBF S. epidermidis isolates, it was 54.5% and 45.5% respectively (p=0.67). The incidence of antibiotic resistance to erythromycin and azithromycin in BF and NBF C. acnes isolates was 54.5% and 63.6% respectively (p=1.00), whereas for S. epidermidis BF and NBF isolates, it was 54.5% (p=1.00). There was no resistance observed to tetracycline, doxycycline, levofloxacin, and cotrimoxazole in all groups. There were no significant differences in resistance against seven antibiotics between the C. acnes and S. epidermidis in BF and NBF groups. Furthermore, although statistically not significant, some resistances were observed against clindamycin, erythromycin, and azithromycin. Consequently, the use of these three antibiotics should be judiciously regulated.

The Possible Relation of Demodex and Facial Erythema in Connective Tissue Diseases.

We aimed to investigate the frequency of Demodex infestation and clinical implications in connective tissue disease patients with facial erythema. Patients diagnosed with a connective tissue disease and had facial erythema were consecutively enrolled in the study from 2019-2020. An age and gender matched control group was formed from healthy volunteers. Presence of Demodex was investigated by standardized skin surface biopsy. Number of Demodex mites over 5 per centimeter square was considered meaningful for infestation. Topical or systemic metronidazole treatment was given to the connective tissue disease patients with Demodex infestation. Facial erythema visual analog scale was questioned in patients at treatment onset and one month after. A total of 31 connective tissue disease patients with facial erythema were enrolled. Control group included 31 healthy volunteers. Demographics and comorbidities were similar between groups. Demodex infestation was present in 58.1% of the disease group and in 25.8% of the control group (P=0.01). Pruritus was the most common symptom in patients with infestation. Median (IQR) facial erythema visual analog scale score was 6 (3) at treatment onset and was 2 (2.5) one month later (P<0.001). When evaluating facial cutaneous lesions, Demodex infestation should not be overlooked in a patient group like connective tissue diseases with dysfunctional immune system.

STANDARDIZED SKIN SURFACE BIOPSY - A BETTER DIAGNOSTIC OPTION FOR DEMODICOSIS IN MACULAR ROSACEA IN VIETNAMESE PATIENTS

Introduction: Demodicidosis is a chronic skin disease, caused by two species of Demodex (D. folliculorum and D. brevis). Demodex infected individuals are mainly symptomless and may have pathogenic symptom only when mite density is high within the skin.Objectives: To compare the value of the Standardized skin surface biopsy (SSSB) and direct microscopic examination with KOH (DME) for assessing Demodex density.Methods: Fifty patients with demodicosis were determined Demodex by SSSB and DME. Comparision of the similarity of test results between the two methods was conducted by Cohen’s Kappa statistic.Results: The positive test rate of SSSB is 90.0%, of DME is 82.0%. The percentage of patients who tested positive for both methods was 76.0%, and the negative for both methods was 4.0%. Demodexdensity &gt; 5/cm2of SSSB was 47.9% higher than DME of 29.2%. There was quite similarity of Demodexdensity between SSSB and DME with coefficient kappa = 0.62. Conclusion: SSSB is more sensitive method for detecting Demodex than DME, particularly in patients with macular lesions, vasodilatation, U-shaped distribution, located on the nose and nasolabial sulcus.

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

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. 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. 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%. 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.

Boosting hair growth through follicular delivery of Melatonin through lecithin-enhanced Pickering emulsion stabilized by chitosan-dextran nanoparticles in testosterone induced androgenic alopecia rat model

The strategy in this work was loading Melatonin (MEL), the powerful antioxidant photosensitive molecule, in novel Pickering emulsions (PEs) stabilized by chitosan-dextran sulphate nanoparticles (CS-DS NPs) and enhanced by lecithin, for treatment of androgenic alopecia (AGA). Biodegradable CS-DS NPs dispersion was prepared by polyelectrolyte complexation and optimized for PEs stabilization. PEs were characterized for droplet size, zeta potential, morphology, photostability and antioxidant activity. Ex-vivo permeation study through rat full thickness skin was conducted with optimized formula. Differential tape stripping trailed by cyanoacrylate skin surface biopsy was executed, for quantifying MEL in skin compartments and hair follicles. In-vivo evaluation of MEL PE hair growth activity was performed on testosterone induced AGA rat model. Visual inspection followed by anagen to telogen phase ratio (A/T) and histopathological examinations were conducted and compared with marketed 5% minoxidil spray “Rogaine ®”. Data showed that PE improved MEL antioxidant activity and photostability. Ex-vivo results displayed MEL PE high follicular deposition. In-vivo study demonstrated that MEL PE treated testosterone induced AGA rat group, restored hair loss and produced maximum hair regeneration along with prolonged anagen phase amongst tested groups. The histopathological examination revealed that MEL PE prolonged anagen stage, increased follicular density and A/T ratio by 1.5-fold. The results suggested that lecithin-enhanced PE stabilized by CS-DS NPs was found to be an effective approach to enhance photostability, antioxidant activity and follicular delivery of MEL. Thus, MEL-loaded PE could be a promising competitor to commercially marketed Minoxidil for treatment of AGA.

Long-Term Use of Silybum marianum fruit extract Contributes to Homeostasis in Acne-Prone Skin-A 12-Month Follow-Up International "Real Life" Cohort Study.

Homeostasis in the differentiation programme of sebaceous stem cells has been identified as a key step in comedogenesis and should be a target for acne-prone skin care. To report on a multicentre, year-long/real-life use study of a patented natural product containing S. marianum fruit extract proven to modulate molecular actors in the initial steps of comedogenesis. An open-label multicentric international study, with a 12 month follow-up, included 54 teenage and young adult subjects with mild to moderate facial acne. The study was aimed at reproducing a real-life use context. Total lesion count mean was 88.3 at inclusion. There was a sustained, highly significant decrease over the months of clinical lesion counts (45.6% improvement after 6 months and 59.6% at 12 months) and on other efficacy markers, associated with a significant decrease in global microcomedone quantity on cyanoacrylate superficial skin surface biopsies. Importantly, the study protocol allowed the dermatologist to prescribe, if needed as in real life, any of the acne drugs registered in the acne guidelines. The exposure to these acne drugs during the whole year was calculated as a percentage of S. marianum fruit extract/352 days of use and happened to be very limited at less than 4%, which indicates a marginal contribution to the sustained clinical improvement. (Oral and local acne treatments: Lymecycline 1.46%; Doxycycline 0.24%; Adapalene 0.16% or gel association with Benzoyl peroxide 1.17%; Clindamycin 0.04%; Benzoyl peroxide 1.5%; Erythromycin 0.75%). The tolerance with daily S. marianum fruit extract long-term use was good. The association with routine prescription acne drugs when needed, even if limited, does not allow a full evaluation of the intrinsic quantitative efficacy of S. marianum fruit extract in lesion reduction. This open, real-life, year-long multicentre study confirms a previous 48-week proof of concept study and qualifies the use of S. marianum fruit extract as a "field-dermo cosmetic" contributing to homeostasis of acne-prone skin in association with acne drugs.

Papulopustular periorbital demodicosis: A diagnosis often overlooked

Demodicosis is the term given for cutaneous diseases caused by the human ectoparasitic mites Demodex folliculorum and Demodex brevis which are common commensals of the pilosebaceous units in human beings. We report a 72-year-old female who presented with erythematous papulopustular lesions over both upper and lower eyelids and a few similar lesions on the cheeks of 2 weeks duration with one similar episode in the past. A cyanoacrylate standardized skin surface biopsy showed increased mite density and the patient was successfully treated with acaricides. Demodicosis is often misdiagnosed as contact dermatitis, papulopustular rosacea, or seborrheic dermatitis. A high index of suspicion of demodicosis is needed to arrive at an accurate diagnosis.

Translated article] Association Between Demodex Infestation and Severe Acne Vulgaris: A Cross-Sectional Study of 168 Patients

Background and objectivesInfestation with Demodex mites has been associated with acne vulgaris. The aim of this study was to explore the association between Demodex infestation and severe acne vulgaris in outpatients seen at Hospital Regional Lambayeque in Chiclayo, Peru. Material and methodsWe conducted a cross-sectional study of 46 patients with severe acne and 92 patients with nonsevere acne. Severe acne vulgaris was diagnosed if the score was 3 or more on the Spanish Acne Severity Scale (EGAE, in its Spanish acronym). Demodex infestation was diagnosed when a skin surface biopsy showed more than 5mites/cm2. ResultsThe patients had a median age of 18 years (interquartile range, 15–20 years), 60.9% were male, 81.9% lived in an urban area, and 29.7% were infested with Demodex mites. In the bivariate analysis, severe acne vulgaris was significantly associated with Demodex infestation (P=.001), sex (P=.003), residence (P=.015), a paternal history of acne (P=.045), a maternal history of acne (P=.045), and type of skin (P<.001). In the multivariate analysis, after adjustment for male sex, urban residence, previous treatment, maternal and paternal history of acne vulgaris, and an oily skin type, patients with Demodex infestation were 4.2 times more likely to have severe acne vulgaris (95% CI: 1.6–10.9, P=.003). ConclusionDemodex infestation was associated with severe acne vulgaris in outpatients at our hospital.

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

BackgroundThere 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 MethodsA 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.ResultsThe 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).ConclusionThis 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.