Human Demodecosis: Hypotheses and Facts

R. D. Zhaxylykova (2013), PhD, member of EURAAC and EAACI, clinician with 49 years of experience. E-mail: zhax-rd@mail.ru

Abstract

In 1970s in natural conditions, infestation with human Demodecosis was traced first among patients, colleagues and visitors of the Republican Clinical Hospital, and later among the population and tourists in Alma-Ata. With a background of the others’ healthy skin, it was not hard to grasp the minimal changes that occur on healthy skin when it is damaged by Demodexes.

Even back in those years, changes were found on the skin of the prevailing part of the inpatients similar to lesions of the skin damaged by Demodexes. Positive results of treatment ex juvantibus confirmed the mite nature of those changes. This fact allowed to put in doubt the symbiotic role of Demodexes for humans.

Over the past 40 years we have carefully studied the clinical manifestations of Demodecosis, analyzed existing and developed new non-invasive diagnostic methods, generalized effective ways of curing various manifestations and complications (clinical masks) of Demodecosis.

70-95% of admitted patients with previous allergological diagnoses fully recovered as a result of our anti-mite treatment amid careful elimination of biotope from mites’ allergens. This fact proves the mite etiology of prevailing part of allergic diseases.

Keywords: Demodecosis; anti-mite treatment; allergy; mite allergens, treatment of allergy.

Introduction

Despite the fact that over 170 years have passed since the discovery of Demodex mites (since 1841), the issue of the pathogenic role of this mite to humans is still being discussed. Some researchers place it among symbionts /1/. Others acknowledge its possible pathogenic role upon occurrence of aggravating circumstances for host /2/. Still others consider it to be the reason for the development of demodectic blepharoconjunctivitis, discoid lupus erythematosus and acne rosacea /3, 4/. At the same time, the case was described of severe systemic damage of the human body referred to as ‘Demodecosis gravis’. There is a mention in the literature that at the junction between the old and the new eras Demodex was deemed causative of almost all human skin diseases. In veterinary Demodex is definitely deemed a pathogenic microorganism /5/.

Disputes continue about strict species specificity of Demodexes for hosts /6/. Morphology and biology of this mite is fairly well studied. Like any mite, Demodex possesses tremendous adaptability. Body build of this mite allows it to move on any surface and in any tissue. Glandular tissue is a favorite place for the localization of this mite. Demodex breathes through the surface of its body. But there is information that some of its representatives have shifted to anaerobic type of respiration.

In medicine, for a long time it was erroneously thought that demodexes creep out of pores to the surface of the skin to lay eggs, which is contrary to the law of the conservation of species. If demodexes really feed on desquamated epithelium of the inner wall of skin glands, as it is believed in medicine, then they should be considered among the sanitars which clean out the lumen of glands from wastage. However, in parasitology, veterinary, zoology, and acarology it is described that demodexes form colonies in skin glands, while in glandular tissue (sub-skin and other places) they form Krulikovsky’s spherules.

No one would be surprised by isolation of demodexes from human skin, as these mites have been isolated from human skin in a high percentage of the studied cases by almost all researchers on all continents and at all times. Yet, Demodex is rarely found in house dust /7/. Although human skin glands are deemed a favorite place for localization of Demodex, many researchers found Demodex in human body excretions (saliva, tear fluid, sputum, bile, feces, etc.). Demodexes were found in glandular tissue, that lines the bed of nerve fibers, and in soft nasal tissue. There have been recorded instances where demodexes were found in the lymph vessels and nodes, in spleen and liver. Antibodies to components of demodex’s body were found in the blood of patients with demodectic blepharoconjunctivitis /8/. There are mentions in parasitology that in theory Demodex mites are able to cause Demodecosis in humans, but in medicine it is unstudied and undescribed in a holistic form.

Materials and methods

Beginning in 1973, at the premises of the Gastroenterological Department of the Republican Clinical Hospital in Alma-Ata a scientific work was conducted for the formulation of dietotherapy, using national food products, of patients with chronic hepatitis. Among the observed was a patient with discoid lupus erythematosus. From the lesion on her face a huge number of demodexes was exuding, which prompted doubts about the assertion of the consultant dermatologists on the absolute hazardlessness of the patient for the others. This fact prompted to monitor skin of all people who were in contact with the patient. So we have become unwitting witnesses of demodexes’ transition from human to human in vivo.

Changes caused by ingress of demodexes on healthy skin of humans were so clear and eventually evolved so characteristically that we involuntarily began to give an eye to the skin of all people around us (co-workers, visitors to the hospital, friends, people in public places). Similar changes of skin integument were found more often in hospitalized patients, including patients with chronic hepatitis managed by us. To make sure that those changes and skin itching were of mite etiology, during five years we applied external anti-mite treatment ex juvantibus in a group of 186 patients in parallel with observing a similar group of 131 patients, for which we did not prescribe such treatment.

The apparent high-level development of medical science and technology in the twentieth century precluded us from suspecting existence among the population of an infectious disease, that is not taken into consideration in the medical practice. This fact led us to undertake a clinical experiment on the 10^th of August 1980 – autoinfestation with Demodecosis. In the course of a clinical experiment, at the stage of developed allergic complication, two kittens, prepared for experiment, were infested with the material collected from the skin of the test object.

January to December 1981, we examined the skin of exposed parts of the body of residents and tourists in Alma-Ata in order to determine the prevalence of demodectic acariasis among the population. In addition, we conducted targeted medical examinations in organized collectives (colleges, hospitals, workplaces, schools, kindergartens, etc.). In the ensuing years, for the same purpose we examined the skin of open parts of the body of residents of 26 cities in Europe and Asia during our visits there.

It should be emphasized that, whenever needed, the acarological surveys were conducted. Beginning in 1982, as an allergist-dermatologist we treated admitted patients, taking into account the new phenomena, discovered by us, and using only means and tools allowed in practical healthcare. After the collapse of the Soviet Union, we carried out treatment of patients on a fee basis. In 1993 to 1997, together with V.N. Kusov, acarologist and doctor of biological sciences, we conducted a comprehensive surveillance which included acarological survey of managed patients and their biotope.

Thus, we involuntarily find ourselves on a scientific research with an extemporaneous plan. We were unsuccessful in attaining any funding for this work. We continued further observations at the expense of our own time and money, in parallel with the work of a general practitioner (allergist-dermatologist, rheumatologist, therapeutist). And we have obtained unique data, which would hardly be obtained when carrying out a scheduled scientific research.

Results

Sexennial observation of 342 people, who initially had had healthy skin and then had direct and indirect contact with the patient with discoid lupus erythematosus, revealed their infestation with demodexes. Gradually, they evolved Demodecosis, at different rates and with different onset. Mastered methods of detection of minimal symptoms of skin lesions, caused by demodexes, found Demodecosis in 96% of 388,780 people, when examining the entire skin integument, and in 98% of 2 million people, when inspecting the skin of open parts of their bodies. Among the examined residents of 26 cities in Europe and Asia, people with healthy skin were not found.

As a result of anti-mite treatment ex juvantibus, in the main group skin itching disappeared after 3-17 days of treatment, while in the control group it disappeared after 9-18 days. Two months later, itchy skin was absent in almost all patients of the main group and only in 30% of the control group. The facts have instilled in us the confidence in the objectivity of the conducted observations. This confidence was reinforced by a successful experiment on volunteer and by positive result of infestation of two kittens with the material from the skin of the object. In 1981, absolute persuasion in objectivity of the studies led us to familiarize health officials and leading specialists, dermatologists and allergists, with our findings. On top of that, our firm confidence in the inerrancy of the observations is substantiated with the positive result of anti-mite treatment of 42,980 patients, who during those 39 years applied to us for medical assistance. Acarological examination of 41.5% of the patients found Demodexes in 99.8%, which included 1.2% with also found Dermatophagoidesses, and in 0.3% were found Sarcoptesses. In 0.2% of the studies no mites were found. In 18 people with healthy skin mites were not found in the skin. 92% of admitted patients previously had been unsuccessfully treated in different medical institutions and/or by healers. Before applying to us those patients had diagnoses listed in Table 1.

Table 1. Diagnoses of admitted patients

The afore said scope of research allows to describe briefly the following initial clinic of demodectic acariasis.

Due to peculiarities of conducted observation, it was difficult to determine the incubation period of Demodecosis. We can only put particular cases and tentatively judge the length of the incubation period. For instance, the changes caused by exposure of healthy skin to single mites were observed by us in the very first few days of contact with the source of infestation. In the clinical experiment the emergence was noted of mild pinkness above matte-white skin on the second day after the infestation. In a young girl, who had been directed for advice to the dermatovenerologic dispensary with a diagnose "Acute urticaria?", rashes and itching all over her body appeared in the first 24 hours from the start of a massive infestation. In the observed patients infested with the mites, characteristic changes slowly evolved in different parts of the skin, but the time when the mites got on their skin was not known to us. The described facts indicate at short length of the incubation period of Demodecosis. But initial manifestations of the disease are often so minimal, that for a long time infected people do not focus attention on them. It is possible that in Demodecosis, as with any primary chronic infectious disease, there is also a high percentage of latent and atypical variants.

Of subjective symptoms the most common is itchy skin. But at Demodecosis it is very versatile and is easily alleviated by diversion of patient, admission of antihistamine drugs and sedatives, in a cool room, etc. When infested with a small number of mites, patients for quite a long time do not sense skin itching. To be more exact, itch is present but is extremely mild and transient. For such patients, light stroking or light scratching is quite enough to stop itching. When a massive infestation with mites, itchy skin becomes more severe and is sensed by many infected. A characteristic feature of itching at Demodecosis, as in any acariasis, is its increasing intensity at evening and night time. If excessive skin lesion by demodexes, there may be burning, prickly sensation, focal tics, etc.

Initial changes of the skin depend on the amount of inoculated infectious material. When one mite gets onto skin, light dotty pinkness appears. With each passing day, this pink dot becomes of more intensive colour. In a certain time, the redness spreads out, that coincides with the time of resettlement of a new batch of mites to other pores of the skin. At this, skin obtains barely noticeable pinkness on considerable area. Thereafter, the intensity of the pink colouring of already a larger zone slowly increases. In locations of the densest inhabitation of mites, redness of the skin becomes express. This process continues a long time until more or less full colonization of all the skin pores by mites. Duration of this period varies in different people and depends on the prevalence of factors (household, industrial, food, weekend, etc.) mitigating or conductive to progression of the acariasis process.

Objective changes on the skin massively infected by mites may vary widely: from changes in colour to emergence of various rashes. The colour of the skin changes. When infected by demodexes, most often the colour of the skin turns to pink or livid red. In practice, as a rule, there is a mixed mite invasion in which skin colour turns gray, brown, dark with a dingy and even a black tint. Appear pigmented and/or depigmented spots, chloasma, enlarged pores as black dots, freckles, excessive greasiness or dryness of some areas, papules, pustules, cutaneous horn, warts, frequent sties or furuncles, chalazion, etc. Pre-eminent lesion of hair follicles may be accompanied by transient increase of hair growth, which soon turns into intense hair loss with the development of diffuse or focal alopecia. Wrinkles appear, which, in young patients, are interpreted as mimic or caused by wrong position of the head and neck in bed, and in the elderly patients are linked with aging. In the latter excessive abundance of wrinkles often develop, which sometimes give the skin the appearance of cobblestone pavement.

It should be stressed that healthy skin is never neither oily nor dry. Without treatment, acariatic changes (including demodectic changes) on the skin nothing else but progress. The rate of progression of these changes depends on the level of personal hygiene, the general condition of the macroorganism, the degree of mite inhabitation of the biotope, and many other factors. In people with weakened immunity, changes in the skin quickly progress and lead to the development of various systemic complications. Total inhabitation of hypoderm by mites increases its aeriferousness, which seemingly attaches a look of hormone wellbeing of the body to the young. In some patients, ‘snow squeaking’ is felt under the fingers when palpating such skin.

In our opinion, it is wrong to point out the places beloved for the localization by demodexes. Demodex definitely inhabits glands at all sites of the skin, including the extremities, palms, soles, scalp, genitals, and subsequently glands of the mucous membranes communicating with external environment (ophthalmic, nasal, oral, auditory meatus, anal, urethral, etc.) Unfortunately, clinical observations show that demodexes live freely in the internal organs and tissues of the infested. Extremely rare but there are patients who perceive the presence of mites inside their body. For example, a patient with Demodecosis approached to us that sensed movement of ‘insects’ along thigh muscles. Another patient sensed ‘movement of insects’ and itching in the large bronchi. In both cases, the perceived itch was eliminated by etiopathogenetic treatment.

The abundance of demodexes in the outer layers of skin is accompanied by the development of skin pathology and other clinical masks described earlier /9/.

Discussion

Why were we able to ‘catch’ the first symptoms of skin lesions by demodexes? Firstly, in the course of the main scientific work we had established the methodology of over-time clinical monitoring of the patients’ skin. Secondly, in that time period (the beginning of the 1970 's) lot of people had healthy skin, and the introduction of even one mite into healthy skin was visually well noticeable. Thirdly, we were critical about the hazardlessness of the patient, from the skin of whom a huge amount of demodexes was exuding. All these reasons allow us to eventually grasp those minimal manifestations that occur on healthy skin of people at initial stages of its infestation with demodexes.

Why did we believe in the lead role of mites in the origins of itching skin observed in patients with chronic hepatitis? Exactly because anti-mite treatment delivered them from itchy skin faster and for longer periods than in the control group of patients who did not receive anti-mite treatment. In addition, local anti-mite treatment very quickly brought the surface of the skin to normal condition both in color and skin purification from various lesions (papillomas, warts, blemishes, etc.).

Why did the allergic complication primarily develop in experimentally reproduced Demodecosis? Firstly, the occurrence of allergies in human body infected with mites is a quite predictable fact. Components and discharge of any mites are alien to the human body, i.e. are allergenic. It is an axiom. In the immunocompetent organism, antibodies are generated to allergens. This is an axiom too. /10/. Anti-mite means used in the subject patient resulted in a mass death of mites that lived in his skin. At this, a huge amount of mite allergens discharged. A reaction developed of connection of antigens with antibodies, well described by immunologists. As a result, allergy mediators generated, that provoked a stormy development of a clinical allergic reaction on the skin in the form of redness, edema, oozing lesion, burning and eventually led to disability of the person who had never had allergic problems. This judgement was confirmed by sufficiently rapid disappearance of symptoms after applying antihistamines /11/.

Demodecosis primarily affects the skin and mucous membranes that communicate with the ambient environment. Exactly because of Demodecosis, in our view, almost all allergists note the development of allergies in the first place on skin and mucous membranes. Full cure of 70-95% of patients with allergological diagnoses after conducted anti-mite treatment testifies that the leading causative factor of allergies in those patients were mites that had lived in their organism and caused acariasis undiagnosed by medicine.

Could the discoverers, that reckoned demodexes among saprophytic microorganisms of human skin, be wrong? There might be a two-fold opinion. Possibly, 170 years ago demodexes were indeed saprophytes of human skin. However, according to the laws of biology, too long lasting symbiosis after such a long period of time could morph first into ecto-, and subsequently into endo-parasitic mode of life. In favour of the latter opinion is the statement of allergic reactions in allergological patients not only from part of the skin and mucosa communicating with ambient environment, but also from part of internal organs. On the other hand, scabiologists have confirmed the existence of a ‘residual’, ‘acarophobic itching’ in patients treated from the classic scab. That is sarcoptic mange was cured, but ‘acarophobic itching’ /12, 13/ remained, and it could be due to demodexes remaining in the body of patients. According to the laws of biology, remaining demodexes, in the complete absence of natural antagonists of the microcosm (Sarcoptes scabiei, lice, etc.) and lack of control from the host part, could have gradually filled all the ecological niches in the human body and its immediate environment, which, apparently, is currently true.

Coincidence or pattern, but in the 1970's we discovered the exponential spread of Demodecosis among the population of the planet. In fact, allergies proved to be among the earliest and most frequent clinical masks of demodectic acariasis. Therefore, pandemic Demodecosis could lead to increase of incidence of allergies in geometric progression, which allergists stated over the last thirty years of the past century.

Complications (i.e., clinical masks) of demodectic acariasis are diverse, since Demodecosis is undiagnosed and there is no proper control of it. Indicative information on the structure of the clinical masks of demodectic acariasis is given in the above Table 1. In more detail many clinical masks of acariasis were described by us earlier /14/. The complete eradication of Demodecosis and its widespread clinical masks can provide rehabilitation of the world's population from many primary chronic non-communicable diseases (NCDs).

Conclusion

Results of 40-year clinical and laboratory observations indicate that mites of Demodex genus definitely cause in human a primary chronic invasive disease: Demodecosis (demodectic acariasis). Infection with Demodecosis occurs through direct and indirect contact with a source of infestation (from demodectic patient, from things and objects contaminated with mites, etc.). The extent of the conducted research and the rates of incidence of allergy - one of the earliest and most frequent clinical masks of Demodecosis, indicate that currently Demodecosis is pandemically present among the population of the planet. As a primary chronic infectious disease, Demodecosis has a significant percentage of latent and subclinical variants, number of which is to be determined in the future. Due to the lack of proper control, Demodecosis exists in the form of various clinical masks, which practically are the object of study and the work of doctors in all clinical specialties. Hence, liquidation of Demodecosis can provide a recovery from its various clinical masks, representing a considerable part of the initially-chronic NCDs of human.

Summary

Mites of the Demodex genus are pathogenic for humans and definitely cause Demodecosis (demodectic acariasis).

Demodecosis and its clinical masks are widely spread among the population.

Liquidation of Demodecosis and its clinical masks can provide a dramatic decrease in the incidence of primary chronic NCDs.

For liquidation of Demodecosis, a thorough knowledge is required of its clinical picture by all clinician doctors.

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