[Primary human demodicosis. A disease sui generis]

The Effect of Volatile Oil from Chinese Mugwort Leaf on Human Demodecid Mites In Vitro

BACKGROUND

Human demodecid mites including Demodex folliculorum and Demodex brevis Akbulatova can cause acne, rosacea, epifolliculitis, blepharitis, seborrheic dermatitis, perioral dermatitis, acromastitis and such skin health problems. Artemisia (Composiate) are widely distributed in temperate regions in the northern hemisphere. It has been reported that 17 species of plants in Artemisia used to be mugwort in China. Mugwort volatile oil (MVO) has antibacterial and antiviral effects, can relieve cough and asthma, acts as an expectorant, choleretic and sedative, and promotes circulation and enhances immunity.

PURPOSE

This research was to observe the effect of MVO on two types of human demodecid mites in vitro.

METHODS

The MVO was obtained via the supercritical CO₂ extraction method, and the human demodecid mites were acquired with cellophane tape. MVO had a distinct killing effect on two types of human demodecid mites, Demodex folliculorum and Demodex brevis. The body of the demodecid mites has a classical temporal process, which consists of excitement, contractions, death and transparency. The killing time was lengthened with decreasing concentration, thus showing an evident dependence on concentration.

RESULTS

The experiment showed that 3.125% was the minimum effective concentration of MVO for killing D. brevis, and 6.25% was the minimum effective concentration for killing D. folliculorum; the killing effect of MVO on D. brevis was greater than on D. follilorum.

CONCLUSION

This result suggests that mugwort, which acts as a traditional Chinese herbal medicine, has a noticeable killing effect on human demodecid mites.

Primary facial demodicosis as a health problem and aesthetic challenge: A case report

Colonization of skin by Demodex mites developing as a single facial lesion with a limited range is diagnosed relatively rarely. The presence of this type of skin lesions may hinder and thus delay the diagnostic process and application of appropriate treatment. The persistent cosmetic defect on the face is extremely onerous/embarrassing to the patient and impedes normal functioning. Describe a case of atypical presentation of primary facial demodicosis and its successful treatment. We present a case of a 38-year-old patient who consulted an aesthetic medicine doctor about a skin lesion, that is, erythematous-papular lesion with single pustules persisting for more than half a year around the right eye corner and below the lower eyelid. Previous topical antibiotic treatment has proved ineffective. Diagnosis was targeted at detection of Demodex spp. invasion, which yielded a positive result. Targeted therapy with 1% topical ivermectin was implemented. Complete resolution of the skin lesions was observed after 8.5 weeks of the treatment with no further recurrence. In the case of limited scaly erythematous-papular skin lesions with single pustules, Demodex mites should be considered as an etiological factor or one of the factors in the case of a mixed-etiology lesion. A delayed diagnosis of visible lesions on facial skin has a negative impact on patient's well-being and normal functioning. As diagnosis of primary demodicosis is underestimated, knowledge about this dermatosis and its clinical manifestations should be disseminated among cosmetologists and doctors of various specialties.