Deep skin miass: causes, symptoms, diagnosis, treatment

To the group of deep miasses (myasis cutis profunda) are various in the etiologic sense and in the nature of the clinical course of the disease, the combined factor of which is the deep penetration of the larvae into the dermis, subcutaneous fatty tissue and deep tissue. Deep skin mias differ malignant flow. Among them are isolated an ordinary deep miass, an African miase, or cordilobiosis, and a South American miase, or dermatobiosis.

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Deep skin miasma

Ordinary deep skin myasis (myasis vulgaris profunda) as a kind of deep miass other than hot countries is sometimes observed in countries of temperate climate, including Russia, where the miase of the eye (ophthalmomiasis), myasis with hearing damage, the mias of the nose area, the tongue , the urethra.

The causative agents of the common deep mias may be the larvae of the following flies: Wohlfortia magnifica, W. Veigil, W. Intermedia (North America, southern Europe, a number of Middle Eastern countries, Egypt, China, Mongolia), Chrisomyia hominivorax, Ch. Macellarica, Ch. Bezziana, Vilinemee and others (East Africa, some Asian countries).

With an ordinary deep mise, female flies usually lay eggs in the foci of various skin lesions (suppurating abrasions, wounds, ulcers, etc.). The larvae formed from the testicles, in contrast to the surface miases, feed not only necrotic but also healthy tissues. At close examination (especially with the help of a magnifying glass) at this stage in the wound one can notice a peculiar movement of the larvae, which, under the overhanging edges of ulcers or folds, are located as if in whole colonies. They, eating away tissues, not only cause destruction of them, but can even be the cause of the development of deep defects. In such cases, the patient usually has general symptoms of deep skin miasma in the form of fever, headaches, weakness, almost non-abating acute pain; even faint states are possible.

In addition to the skin, larvae can also be found on the mucous membrane of the mouth, nose, eyes, where, while mucous membranes are devoured, they make deep passages in the tissues, down to the fascia and even the periosteum, which leads to extensive and severe destruction of not only soft but even cartilaginous and the bones of the larynx, nasopharynx, paranasal sinuses, eye sockets, middle ear, etc. Even cases of complete destruction of the eyeball with the development of encephalitis and fatal outcome are known.

Although the period of parasitism of wolfar flies larvae on a man does not exceed usually 3-6 days, after which they disappear from the skin and pupate outside the body, this is enough to cause deep destruction. It is possible that in a number of cases, obviously, there are repeated postponing of new and new portions of eggs. Moreover, it is known that sometimes pockets of ordinary deep miasses as a result of deposition of new larvae by other species of flies can become "mixed".

Treatment of Deep Skin Mimosa

First of all, it is important to remove all larvae from the lesions as early as possible. In most cases, it is sufficient to wash the focus with any disinfectant solution (1% chloroform water, 2% resorcinol solution, potassium permanganate solution, etc.). According to the indications, antibiotics, sulfonamides are used, and in cases of deep purulent processes - surgical intervention.

African miase

African mias (myasis africana), or furunculoid mias (synonym: cordilobiasis ) is found especially often on the African mainland.

Its causative agent is the larva of the fly Cordilobia anthropophaga. The path of infection can be as follows: a fliesfly lays a large number of eggs on urine contaminated with urine and organic waste. The tiny larvae hatched from them, when they come into contact with human skin, as well as some mammals, in particular dogs, rats, etc., are actively introduced into the thickness of the skin.

Most often, the African miase affects children as a result of playing with the land, as well as adults who have contact with the earth, especially in production conditions (workers in rice, coffee, rubber plantations, etc.). After 1-2 days at the site of introduction into the skin of the larvae, a hyperemia center appears, at the base of which palpation can determine the nodular infiltrate. As the infiltrate increases in the coming days, a furuncle-like node is formed, which in the center has a small opening for accessing the air to the larva. The clinical symptoms of the African miase fundamentally distinguish the furunculoid mias from the staphylococcus aureus with its necrotic stem in the center.

On the 12-15th days from the onset of the disease, the larva begins to protrude from the enlarged opening leading to the cavity of the node, as it grows. At this stage, it can have a length of up to 10-15 mm. With a favorable outcome, she soon leaves the skin, dropping into the external environment and pupating already in the soil, after which the wound heals. Often furunculoid miase occurs in the form of a single focus, but there are numerous cases of multiple penetration of larvae into the skin of one person with the formation of several furuncle-like infiltrates.

In some patients, infection and suppuration of the wound can occur with the formation of a vast abscess. This development of events is particularly facilitated by the rupture of the larva with an inept attempt to extract it, as well as contamination of the wound.

Treatment of the African miase

Before the maturation of the larva, any therapeutic measures, especially mechanical extrusion, are inexpedient and can only lead to secondary infection. Treatment of the African miase begins with a mature larva and an enlarged vent of the vent and is the careful mechanical removal of the larva by stretching the skin around the focus. In order to accelerate the escape of the larva, it is possible to fill the funnel-shaped opening of the opening with some sterile oil (camphor, vaseline, peach, etc.), while the larva, deprived of air access, approaches the surface of the skin and begins to expose its usually posterior end of the body with the respiratory apparatus . At this point, it can easily be removed with tweezers.

After removing the larva, the released cavity is washed with any disinfectant solution and an antiseptic dressing is applied. When complicating secondary infection, external or systemic antibiotics can be indicated.

Deep skin miases can be prevented. Preventive control measures are mainly focused on early detection and timely rational treatment of all skin lesions, as well as preventing access to flies; for this purpose, the use of repellents is recommended. Important is also the destruction of flies, the fight against the miasma of animals, especially rats, dogs.

South American miase

The South American miase (myasis Sudamericana) is a kind of deep miase (synonym: dermatobiasis - dermatobiasis) found mainly in some subtropical countries of Latin America. Its causative agent is the larva of the human gadfly - Dermatobia hominis. Unlike the above-described African miase, in this species the female of the gadfly does not lay eggs in the soil, but it glues them to the body of blood-sucking dipterous insects (mosquitoes, flies, flies and even houseflies) and some species of mites, where it occurs larval maturation. Then, when these insects attacked human skin (as well as domestic ungulates, monkeys, jaguars, tigers, birds, etc.), the larvae released from the testicles quickly and very actively enter into it.

The further course of the disease is characterized by the formation in a few days at the site of the introduction of the larvae of the inflammatory infiltrate, and then the subcutaneous node, which, in turn, turns into an abscess. It is opened with the release of a small amount of serous-purulent fluid and the formation of a fistulous motion, which is necessary for the larva to access the air. In the abscess cavity, the larva continues to develop and after 1-2.5 months, fully ripe (reaching a length of 20-25 mm), leaves the human body and pupates in the soil.

Symptoms of the South American miase are usually negligible and are reduced, mainly, to a moderate feeling of pain, especially in the stage of an adult larva.

The prognosis is mostly good, although the rare case of the death of a city child struck by a multitude of larvae is described.