Russian Study on Demodex Mites and Rosacea Illuminating

[Guide]

image courtesy Wikimedia Commons

The Russian Ministry of Health conducted a detailed study of demodex mites and rosacea on 212 men and women which is illuminating and confirms the effectiveness of using 1% ivermectin in treating rosacea is just as effective as using metronidazole combined therapy. Further, some new information about detecting a demodex mite density count is revealed that is significant news. While the paper is difficult to read, probably due to the translation, here are some of the jewels found in the report: 

(1) Light Microscopy Skin Scraping Not Reliable
According to the report,  if you use a skin scraping with a light microscope, there may be no reliable data on demodex density counts, which says, "The severity of the condition does not depend on the quantitative load of the mites in the scrape." The report states that "in the light microscopy of scrapes of Demodex mites in the number of 5 individuals per 1 cm2, only 6 healthy persons (n=6; 2.8%); in the remaining 66 healthy people (31.2%), the light microscopy of the scrapes was negative."

"As a result of the study, we found that it is difficult to detect the mite by light microscopy of scrape per 1 cm2 of skin."

However when using a 'Confocal laser scanning in vivo microscopy', there is a significantly more reliable data to count on, which this same report concludes, "Confocal laser scanning in vivo microscopy is an effective diagnostic method to detect Demodex mites that does not require preliminary preparation for analysis and allows detecting Demodex mites at the level of the spiky epidermis layer, which is not accessible for scarification, to identify the species belonging to the size of Demodex mites (from 100 up to 200 μm - Demodex brevis, 200 to 400 μm – Demodex folliculorum)."

"Comparing the results obtained by light microscopy and confocal laser scanning in vivo microscopy in patients with rosacea and healthy people, in more cases Demodex mites are detected by confocal laser scanning in vivo microscopy, whereas scrape in these patients were negative."

(2) The report confirms the size and movement of demodex 

"Using a confocal laser scanning in vivo microscope allowed determining the average size of Demodex mites. When determining the size of mites from 100 to 200 μm, it was believed that in this case Demodex brevis was observed, while the average length of the mite was 125 μm; from 200 to 400 μm – Demodex folliculorum with an average length of 293 μm. The average size of the width of Demodex mites was 24 μm." More information on the size of demodex.

"In the examination of healthy people by light microscopy, Demodex mites were detected in 6 cases (2.8%). Given the ability of the mites to move over the surface of the skin at a speed of 8-16 mm/h, as well as random selection of the study site, this fact does not prove the absence of mites." The method of scattered light intensity (SLI) is used as a new quantitative method of evaluating the viability of Demodex mites. 

(3) Topical 1% Ivermectin Just as Effective as Metronidazole
"Antiparasitic drug ivermectin, in the form of an external form (cream), at a concentration of 1% (1 time per day, the general course of 30 days) has a high therapeutic efficacy in patients with associated with Demodex mites (in 93.3% of cases). The effectiveness of external therapy with a drug containing 1% ivermectin (course of 30 days) is comparable to the combined treatment with the systemic drug metronidazole 250 mg per os 2 times a day and the external application of 1% metronidazole (gel) 1 time per day for 30 days."

"Thus, clinical observations demonstrated a lack of superiority in combined antiparasitic therapy using a systemic drug compared to external therapy using a preparation containing 1% ivertmectin as a cream, as confirmed by statistical analysis. Stein et al. showed that after 12 weeks of ivermectin treatment, the skin of patients was defined as clean or almost clean. There was a significant reduction in the percentage of inflammatory lesions in the ivermectin treatment group. The results of the study showed that 1% ivermectin is an effective and safe treatment for inflammatory lesions in patients with rosacea."

(4) No Demodex Mites Detected in Some Patients
This paper reveals that in some humans there are no demodex detected. The report states, "the fact that in 55-100% of cases, mites are detected, both in patients with face dermatosis and with patients having no clinical signs of dermatological illnesses......II group is a comparison group, which was composed of patients with a diagnosis of rosacea with no Demodex mites. In Group II patients, two methods of study of Demodex mites were not found."

What this means is the second comparison group demodex mites were not detected by two methods, light microscope by skin scraping and Confocal laser scanning in vivo microscopy. The study concluded that those in group two had no demodex mites. If this is true, then this is illuminating and definitely  news since most literature says demodex mites are on all humans except new born babies. 

"In 80 patients with rosacea (37.8%) with Demodex mites were detected in an amount of less than 5 individuals per 1 cm2 or were absent altogether with a developed clinical picture of the condition."

However, because of the ability of the mites to move, the report adds this caution: 
"In the examination of healthy people by light microscopy, Demodex mites were detected in 6 cases (2.8%). Given the ability of the mites to move over the surface of the skin at a speed of 8-16 mm/h, as well as random selection of the study site, this fact does not prove the absence of mites."

(5) Role of Demodex on Humans
"Demodex folliculorum shows signs of parasitism, while Demodex folliculorum brevis is a saprophyte."

Most papers state that the role of demodex is not known. This is illuminating and definitely news. 

(6) Demodex Mites are Significantly Higher in Rosacea
"Our findings confirm the hypothesis of Turgut Erdemir et al., that the Demodex mites affect the severity of the disease and contribute to the progression of the pathological process. In addition, the authors have proved that the density of mites increases depending on the severity of the disease."

"The detection of Demodex mites is not only statistically more significant in patients with rosacea than in the rest of the population, but also as can be seen from the Table 2, Demodex mites were more often found in patients with more severe clinical forms of rosacea (pustulous, infiltrative- productive forms)."

(7) Demodex brevis not as significant as Demodex Folliculorum

"In patients with severe manifestations of the condition (pustulous and infiltrative- productive forms of rosacea), the species of the mites Demodex folliculorum (P<0.01) is more often detected. Demodex brevis is found in mild forms of the condition and in healthy people, without showing signs of parasitism."

"When Demodex brevis is found, given its weak possibility of parasitism, treatment with antiparasitic drugs is not indicated."

(8) After 30 days of Ivermectin Treatment there is an INCREASE of demodex mites
"Patients enrolled in subgroup A received only external therapy with a drug containing 1% ivermectin in the form of a cream 1 time per day for 30 days. Patients enrolled in subgroup B received a drug containing 250 mg of metronidazole systemically 2 times a day, externally 1% metronidazole in the form of a gel 1 time per day for 30 days. A repeat visit of the patients took place after 30 days of continuous therapy. Subjectively, treatment regimens of patients were well tolerated, no side effects were noted, no patient was excluded from the study. When comparing the efficacy of the therapy, it was found that statistically significantly more Demodex mites were found after treatment with confocal laser scanning in vivo microscopy (P≤0.05) (Table 7)."

The above is significant news. However, the patients nevertheless improved their rosacea in 30 days and the report concluded: 
"Analysis of the clinical picture showed a positive dynamics of therapy, which manifested itself in a significant decrease in the number of morphological elements characterizing the severity of inflammation (P≤0.05). The effectiveness of the therapy was confirmed by a reduction in subjective complaints of patients after the treatment, and patients who received only external therapy had no complaints of a feeling of lusters of skin and the appearance of greasy lusters, which is an additional advantage."

You can read the entire Russian paper yourself here: 
Dermatol Reports. 2019 Jan 23; 11(1): 7675.
Clinical picture, diagnosis and treatment of rosacea, complicated by Demodex mites
Alexey Kubanov, Yuliya Gallyamova, and Anzhela Kravchenko

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