Scabies or allergies? All about obsessive itching

       Itching is one of the common symptoms with which patients turn to a dermatovenereologist. This is often caused by allergies. But do not forget about such a disease as scabies. It is important to immediately determine the cause of the itching. How to find out at the initial stage? What questions should you ask the patient?

What is scabies?

     Scabies (scabies) is a skin disease caused by mites of the genus Sarcoptes scabiei. Infection with this parasitic skin disease occurs by contact. That is, with close bodily contact. Often, infection occurs when people are in the same bed. Stages of development of the  mite that can infect a person – These are  females and larvae. A group of people where there is a person with scabies is called a focus of infection. When such a focus is detected, the doctor must immediately report it to the SES.

     There are direct and indirect ways of tick transmission. Direct is carried out at night in bed, when the tick is most active. The indirect route is through shared items and bedding. There is also a transient invasion, which can be carried out in saunas, trains, baths, where streams of people use items that were in use by a patient with scabies.

     The pathogenesis of the disease fully reflects the life cycle of the tick, which is divided into 2 periods - short-term cutaneous and long-term intradermal phases.

      The location of the passages in scabies depends on the density of the sweat glands, the type of hair growth, the temperature of the outer skin, the rate of regeneration of the stratum corneum and the structure of the skin. So, often the moves are localized on the hands, elbows, wrists and feet, where the stratum corneum is the thickest. There are also many passages in those areas of the skin where the density of the sweat glands is increased (male genitals, wrists, hands, feet). That is why, when a patient has scabies combined with atopic dermatitis   or ichthyosis vulgaris, there are very few scabies. Also, due to dry skin, they are few in the elderly. But there will be many moves with hyperhidrosis, epidermophytosis and dyshidrotic eczema.

But, given the fact that modern people wash their hands several times a day with soapy chemicals, a patient with scabies may not have these moves at all. Then the diagnosis becomes difficult, because there is no main symptom, but the disease is. The only symptom that can help make a preliminary diagnosis is the time of itching. This is the question that should be asked to the patient in order to make a differential diagnosis with allergies. This is due to the daily activity of ticks.

Daily activity of scabies mites.

 The female is in a calm state during the day. In the evening and at night, she gnaws through the egg knees, laying an egg in each. At the same time, the female deepens the very bottom of this passage, making the subsequent exit of the larvae possible. This is done by every female and every night. One female leaves up to 2 eggs per night. From this process, the itch move on the skin of a patient with scabies is convoluted and consists of parts of moves, which are called the daily move element.

Thus, the nocturnal activity of ticks explains the predominance of the direct route of infection through the bed at night and in the evening, as well as the effectiveness of anti-scabies preparations at night.

Clinical picture of scabies        

     If the infection occurred by larvae, the incubation period lasts 2 weeks. And if the infection happened from a female, then the clinic is immediately visible. Itching is the main characteristic symptom of scabies. It occurs as a result of sensitization of the body to the end products of the vital activity of ticks (excrement, secretion of the glands of the oviduct, oral secretion). Itching appears already after 1-2 weeks with primary infection, and up to 3 weeks & nbsp; - in case of re-infection.

  The second characteristic sign of scabies is the presence of scabies. The skin reacts to the appearance of these same moves. Non-inflammatory vesicles, follicular pustules, also appear. An allergic reaction to the end products of the tick's metabolism is also manifested, which manifests itself on the skin with bloody crusts, scratching and miliary papules. But we found that the skin of each person reacts differently to tick activity. Some burrows do not exist at all (intact burrows), others have vesicles, blisters, pustules and lenticular papules, which is caused by jet burrows. Now the similarity of allergies and scabies becomes clear.

Diagnostic symptoms for scabies:

1. Ardy's symptom - pustular crusts and pustules on and near the elbows.
2. Gorchakov's symptom - bloody crusts in the same place.
3. Michaelis' symptom - impetigo rashes and bloody crusts in the intergluteal crease with a transition to the sacrum.
4. Cesari's symptom – on palpation, an elevation is determined, which indicates the presence of an itch.

Scabies can be complicated by dermatitis and pyoderma. Sometimes - urticaria and microbial eczema.

When a person is infected with ticks from animals (dogs, pigs, horses, wolves, foxes, rabbits), pseudosarcoptic mange develops. With this disease, the incubation period lasts several hours, and typical scabies are absent, because ticks do not multiply in conditions unusual for it. They only penetrate the skin, causing severe itching. Pseudosarcoptic mange is not transmitted from person to person.

Scabies in children occurs with possible damage to the skin of the face and scalp. In infants, even the nail plates can be affected.

Methods for detecting scabies

In our country, the diagnosis of scabies must be confirmed  laboratory. To do this, use:

• Oil vitropressure method - the skin is lubricated with mineral oil, after which granulomas are visualized by pressing on the exfoliating element.
• Method of staining a suspicious element with 5% alcohol solution of iodine, ink, ink or aniline dyes.
• Scraping method - detection of contents in the scabies, vesicles and papules;
• The method of extracting the tick with a needle - after opening the blind end of the stroke. At the same time, sharp needles move in the direction of travel and the female is attached with suction cups to the manipulation needle.
• Dermascopy - must be performed for a patient with scabies.

Treatment and prevention of scabies

Scabies is treated on an outpatient basis. The most effective and commonly used ointments for scabies are benzyl benzoate, medifox, spregal and sulfur ointment. But, regardless of the chosen treatment, there are general principles for treating patients with scabies:

- treatment of all patients in one focus is carried out simultaneously;

- ointments should be applied only in the evening;

- children under 3 years of age are subject to rubbing all areas of the skin, for the rest - with the exception of the scalp.

- carbicides are rubbed only with hands, after which hands must be thoroughly washed;

-  the preparation on the skin must be at least 12 hours;

- treatment of complications should be carried out in parallel with the treatment of scabies;

- change of underwear and bed linen is carried out after the completion of the treatment process.

Treatment of scabies in children

Children under 1 year old can use only Spregal ointment, from 1 to 3 years old - Spregal and Medifox. From 3 years old - no restrictions.

     The doctor must remember that in the treatment of scabies, relapses cannot occur, since the tick does not have long, latent periods. And "relapses" such are the result of non-compliance with treatment regimens, an independent decrease in the concentration of the drug, if the term and frequency of application of the ointment are not observed, as well as the use of the drug in the inactive phases of the tick cycle (in the afternoon) and the use of expired drugs. Reinvasion is possible - re-infection from the primary source of scabies, if the latter has not received adequate treatment.

Prophylaxis of scabies consists in actively identifying patients at physical examinations and in any request for medical help.

It is important to know the preventive measures that will reduce the chances of contracting scabies:

- use of personal hygiene products and bed linen;

- adhere to hygiene standards in saunas, pools, baths;

- follow basic hygiene procedures.

It is not always possible to prevent a disease such as scabies, but by remembering the elementary rules, you can significantly reduce the risk of infection. And most importantly, after reading this article, you will have no doubts at the initial stage of diagnosis whether it is an allergy or scabies.

Health to you and your patients!