Skin scrapings versus standardized skin surface biopsy to detect Demodex mites in patients with facial erythema of uncertain cause – a comparative study

Dermoscopy as a clinical tool for the diagnosis of demodicosis: a retrospective intrapatient case-control study

Dermoscopy has been used for the non-invasive diagnosis of demodicosis. Several studies have evaluated the usefulness of this tool in the diagnosis, however, there are differences in the gold standard (SSSB or KOH test) and criteria of positivity used between studies. Added to this, is the lack of controls and objective quantification of the usefulness of dermoscopic signs in clinically observable and relevant ranges. To validate the usefulness of dermoscopy for the diagnosis of demodicosis by calculating the performance indicators for the different dermoscopic signs. Retrospective intrapatient case-control study, which included adults with suspicion of demodicosis. Dermoscopic photographs and scraping of healthy and lesional skin were obtained. Samples were analyzed microscopically by trained personnel. Photographs were evaluated by determining the presence of Demodex tails (DT), dilated follicular openings (DFO) and dilated blood vessels (DBV) in pre-defined ranges. 64 patients were included (total = 256 samples); the presence of demodex on skin scraping was seen in 69%. Under dermoscopy, the presence of DT in range 11-20/field had a positive likelihood ratio (LR) of 12.10 (95%CI 6.52-22.45) and negative LR 0.32 (95%CI 0.23-0.45). Combined and dichotomized performance for at least one positive sign under dermoscopy (DT > 10/field, DFO > 10/field or DBV > 50% of the field): positive LR 7.14 (95%CI 4.80-10.62) and negative LR 0.11 (95%CI 0.06-0.22). The presence of DT, DFO or DBV has a high correlation with a positive mite test, so the diagnosis of demodicosis could be made only through dermoscopy.

Maintenance of Remission after Oral Metronidazole Add-on Therapy in Rosacea Treatment: A Retrospective, Comparative Study

BACKGROUND

Rosacea is a chronic inflammatory disease which requires treatment to maintain remission.

OBJECTIVE

Recently, the effect of Demodex mites in recurrence of rosacea has been described. Although there is limited data, previous reports have suggested that oral metronidazole demonstrated efficacy in treatment of rosacea.

METHODS

Fifty-eight Korean patients with rosacea who received treatment with oral minocycline (50 mg twice daily) only or with two-week of oral metronidazole (250 mg thrice daily) were evaluated retrospectively. Their responses were evaluated by Investigator's Global Assessment (IGA), Clinician's Erythema Assessment (CEA), and patient's Global Assessment. The recurrence rate and odds ratio of risk factors for recurrence were also estimated.

RESULTS

The combination treatment group reported earlier clinical improvement and lower mean IGA and CEA than the monotherapy group. Approximately 48% of patients with combination treatment did not show relapse within 24 weeks, which is significantly higher than that in the monotherapy group (p=0.042).

CONCLUSION

Add-on therapy of oral metronidazole appeared to be a significant protective factor for recurrence of rosacea (p<0.05). This study suggests that oral metronidazole can be added to oral minocycline to reduce relapses in rosacea patients with tolerable safety.

Demodex Mites in Relation to the Degree of Acne Vulgaris among Egyptian Patients

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Demodex&lt;/i&gt; mites are considered to play a pathogenic role in facial dermatoses as &lt;i&gt;Acne vulgaris&lt;/i&gt;. In this study the association between &lt;i&gt;Acne vulgaris&lt;/i&gt; and &lt;i&gt;Demodex&lt;/i&gt; spp. intensity, kind and activity were investigated. &lt;b&gt;Materials and Methods:&lt;/b&gt; Two degrees of acne was included, mild acne (30 cases) and moderate to severe acne (30 cases), besides 30 healthy subjects as a control. Deep skin scraping followed by direct microscopic detection was applied to diagnose demodicosis. &lt;b&gt;Results:&lt;/b&gt; All the detected mites in moderate to severe acne were &lt;i&gt;D. folliculorum&lt;/i&gt; which was observed in a highly dynamic status with their entire life cycle stages with intensity >5 mites per cm&lt;sup&gt;&lt;a href="2246157_ja"&gt;2&lt;/a&gt;&lt;/sup&gt;. While very few inactive &lt;i&gt;D. brevis&lt;/i&gt; mites were detected in the 2 subjects related to the control group&lt;i&gt;. &lt;/i&gt;Despite that females comprised the majority of acne cases, males encompassed a statistically higher number than females among positive demodicosis cases. Itching and hair loss were the significant clinical signs within positive cases. Regarding risk factors, oily skins, repeated exposure to the sun, stressful lifestyle plus defective use of facial cleansers were found to be statistically significant. &lt;b&gt;Conclusion:&lt;/b&gt; These results attained an association between moderate to severe acne and energetic &lt;i&gt;D. folliculorum&lt;/i&gt; entire population. Thus, this study recommended lifestyle's modification for those cases suffering from &lt;i&gt;Acne vulgaris&lt;/i&gt; with deep facial cleaning to avoid such infestation that worsens acne condition. Accordingly, once acne treatments are ineffective, consideration of &lt;i&gt;Demodex&lt;/i&gt; mites with the needed acaricidal therapy is necessary.

Skin-homing T-cell responses associated with Demodex infestation and rosacea

AIMS

Our aim was to investigate the skin-homing T-cell immune responses triggered in patients with Demodex infestation and/or rosacea.

METHODS

Collected whole blood samples were divided into four groups: control subjects; nonrosacea patients with Demodex infestation (Demodex group); papulopustular rosacea (PPR) patients without Demodex infestation (Rosacea group); and PPR patients with Demodex infestation (Rosacea/Demodex group). Following ex vivo activation, skin-homing CLA+CD4+ T-cell subset levels were monitored by flow cytometry.

RESULTS

When compared with control subjects, among skin-homing CD4+ T-cell subsets analysed, Demodex patients had higher T_H 9 and T_reg cell levels; Rosacea subjects displayed elevated T_H 1 cell levels; and Rosacea/Demodex patients exhibited increased frequencies of T_H 9 and T_H 22 cells. In contrast to Rosacea subjects, Rosacea/Demodex group members displayed higher T_H 2 cell levels; and when compared with Demodex groups, they had higher T_H 1 and T_H 2 but lower T_reg cell levels. Demodex group members also exhibited higher T_reg but lower T_H 1 and T_H 22 levels than Rosacea/Demodex group subjects.

CONCLUSIONS

The skin-homing T-cell responses associated with Demodex infestation and rosacea formation seem to influence each other. The present as well as future studies could contribute to the development of effective treatment strategies for demodicosis and rosacea.