Allergic small tortoiseshell
Allergic small tortoiseshell is a skin pathology of allergic character which can have sharp or chronic character is (more rare). Its symptoms are the skin itch, emergence of the eritematozny elements similar to the rashes remaining after a burn a nettle towering over skin – from here and the name of pathology. Diagnostics is made on the basis of survey of the patient, blood test, determination of level of immunoglobulin E; carrying out immunological researches – allergic tests for allergen identification is possible. Treatment of an allergic small tortoiseshell is made with use of antihistamines, a hypoallergenic diet, immunomodulatory medicines.
Allergic small tortoiseshell
Allergic urticaria (urtikariya) – the skin disease which is shown development of a skin itch, eritematozny rashes and usually provoked by food or other allergy. The similar state is extremely widespread, according to medical statistics, not less than 10-20% of the population of Earth at least once in life tested symptoms of this pathology. In most cases an allergic small tortoiseshell has acuity and after the carried-out treatment (sometimes - it is spontaneous) disappears, without leaving marks on integuments or mucous membranes. The chronic form of a disease, according to some dermatologists, has to be taken out in separate nosological group as it is caused by autoimmune and hereditary factors. Except a true allergic form, there is a concept of "a pseudo-allergic urticaria" which is caused by various physical factors.
Allergic urticaria can affect the person at any age, however in age distribution of patients the prevalence of children is observed. It is explained by immaturity of many immunological processes because of what easily there is an allergy to various factors. The chronic type of an allergic small tortoiseshell develops at female adults more often – in that case it is not possible to establish a cause of illness quite often therefore it is often also called an idiopathic small tortoiseshell. This pathology in itself does not pose a threat for human life, however it can be complicated by angioneurotic hypostasis or anaphylactic shock. These states demand the emergency medical care for preservation of life of the patient.
The reasons which cause skin manifestations differ at various forms of an allergic small tortoiseshell. Usually it is the reaginovy type of hypersensitivity (an allergy of the 1st type) mediated by immunoglobulins like E. Allergenami at this species of an allergic small tortoiseshell food components, pollen of plants, household dust, some medicines and other factors are. In that case skin manifestations act only as one of symptoms of food or other allergy. In certain cases can cause such skin violations also an allergy of the 2nd type – generally it happens at blood transfusions. Intravenous administration of some medicines with development of immunocomplex reaction of intolerance can also cause an allergic small tortoiseshell.
It is noticed that some infectious diseases, endocrine violations, violations of the psycho-emotional sphere increase probability of development of an allergic small tortoiseshell. Especially it is urgent concerning an idiopathic, or chronic form of pathology. The pathogenesis of development of skin violations in this case is studied poorly, both immune, and not immune mechanisms of activation of fabric basophiles of skin are assumed. Therefore in the presence of an allergic small tortoiseshell of not specified etiology make full inspection of an organism of the patient for the purpose of detection of the latent and chronic diseases and violations.
Mass degranulation of fabric basophiles (corpulent cages) is the main reason for skin violations at an allergic small tortoiseshell. The histamine, heparin, leykotriyena and a number of other biologically active connections capable to considerably change metabolic processes in fabrics are a part of granules of these cages. Generally they lead to expansion of blood vessels, increase permeability of their wall, cause accumulation of fabric liquid, stimulate pain receptors of skin that leads to emergence of an itch. In most cases such reactions at an allergic small tortoiseshell have local character and strike only the certain site of skin or, is more rare - all surface of a body. However so mass emission of active connections can sometimes lead to the general reactions as anaphylactic shock and Quincke's hypostasis.
At a pseudo-allergic small tortoiseshell pathogenesis in many respects similar – happens mass activation of fabric basophiles of skin to allocation of biologically active connections. However the reasons and mechanisms of this process a bit differents – it can be the congenital or acquired instability of membranes of corpulent cages, their abnormal reaction to various physical or humoral factors. Besides, in some cases a pseudo-allergic small tortoiseshell, hypersensibility of tissues of skin to a histamine and other components of granules of basophiles is found in the patient. Therefore even insignificant release of these substances can lead to a clinical picture of a small tortoiseshell.
As it was already told above, all forms of an allergic small tortoiseshell are divided into two types – sharp and chronic. The border between them is quite conditional – it is considered that at a sharp form of a rash and an itch no more than 6 weeks whereas if they disturb the patient longer, the diagnosis of a chronic allergic small tortoiseshell is made remain.
Besides, it is important to differentiate a true allergic small tortoiseshell from a pseudo-allergy at which activation of corpulent cages happens without participation of immune mechanisms. There is a set of kinds of such state – for example, to mechanical types of a pseudo-allergy carry the following:
- Dermografichesky small tortoiseshell (urtikarny dermografizm) – is provoked by the simple physical pressure upon skin (clothes seams, for example). In pathogenesis of a dermografichesky small tortoiseshell of a state not immune mechanisms of activation of corpulent cages most often play a role.
- Holodovy small tortoiseshell – such type of a temperature small tortoiseshell meets even more often in recent years. It is found out that at patients with this pathology when cooling the level of some factors of platelets increases and stability of a membrane of corpulent cages decreases. Against the background of hypersensibility of tissues of skin to a histamine it can lead to development of eritematozny rashes and an itch, both at local impact of cold, and at the use of cold dishes and drinks.
- Thermal urticaria – is quite rare option of a small tortoiseshell. As well as in case of an urtikarny dermografizm, in development of this type of a disease the main role is played by not immune mechanisms of activation of corpulent cages – their degranulation happens at temperature increase.
- Solar urticaria (photoallergy) – a provocative factor at the same time is a sunlight. At patients with such type of a small tortoiseshell hypersensibility of skin to a histamine therefore degranulation even of insignificant quantity of corpulent cages leads to noticeable violations is observed.
- Vibration urticaria – is rather rare form, often has symptoms of occupational disease (at construction workers, on production). In this case degranulation of basophiles happens because of mechanical concussion of fabrics.
- Akvagenny small tortoiseshell – did not treat earlier mechanical kinds of a small tortoiseshell, but in recent years there were instructions that as a provocative factor in this case physical impact of streams of water acts. Activation of corpulent cells of skin happens on not immune mechanism and is quite weak, but at hypersensibility of fabrics to a histamine it leads to development of an eritema and an itch.
Besides mechanical factors, the imbalance of the holinerichesky autonomic nervous system can provoke development of a small tortoiseshell. It becomes the reason of development, a so-called holinergichesky small tortoiseshell. Except eritematozny rashes and a skin itch, typical for this pathology, in this case there are also violations of sweating, regulation of temperature of skin. Such species of a small tortoiseshell is often provoked by emotional experiences of the person. Besides, the pigmentary small tortoiseshell having the nature of autoimmune pathology is close to this skin disease. At it in tissues of skin the increased quantity of basophiles which can easily be activated from various factors accumulates.
Symptoms of an allergic small tortoiseshell
Despite a huge variety of species of a small tortoiseshell, and the factors capable to provoke her, symptoms of a disease are rather monotonous and differ only in the expressiveness. To one of the first manifestations serve development of a skin itch and reddening of skin. Such phenomena can have both local, and widespread character, to be symmetrized (at holinergichesky type of a pseudo-allergic small tortoiseshell) or, much more often, asymmetrically. Very quickly (of several minutes till several o'clock) on the place of reddening there are blisters of various size (0,2-5 cm) which can merge among themselves. An important diagnostic symptom of allergic urticaria is painlessness of blisters.
In most cases the specified skin manifestations are allowed within a day, without leaving behind traces – on condition of lack of repeated influence of a provocative factor. Sometimes, at severe forms of an allergic small tortoiseshell, increase of symptoms happens so promptly that rashes on skin develop into angioneurotic hypostasis. Preservation of skin manifestations and development of new rashes demonstrates continuation of action of a provocative factor which, in that case, can have the endogenous nature (as at an idiopathic small tortoiseshell).
In clinical dermatology definition of this disease is made with use of a significant amount of diagnostic receptions in view of a large number of forms of pathology. At survey the painless eritematozny rashes which are acting over the surface of skin, having various sizes and localization come to light. Diagnostics of a sharp form of an allergic small tortoiseshell, especially if it accompanies any allergy, is made on the basis of the allergologichesky anamnesis of the patient and definition in immunoglobulin E level blood. The quantity of eosinophils in blood is not strict diagnostic criterion of this state, especially its sharp or sporadic form, but at is long the remaining rashes the small eozinofiliya is observed. By allergologichesky tests it is possible to reveal a source of an allergy and to correct the patient's diet for the prevention of further attacks of disease.
In those cases if rashes do not disappear within a day against the background of a hypoallergenic diet and an exception of provocative physical factors, it is necessary to survey lymph nodes, to appoint the general and biochemical blood test, to carry out urine studying. All this will allow to reveal pathology which, perhaps, became a starting factor for development of an allergic small tortoiseshell or in due time to distinguish a pseudo-allergic form of this state. In the same way it is necessary to arrive in the presence at the patient of the increased temperature – the urtikariya in itself does not cause a hyperthermia, but some infectious diseases can become the reason of both symptoms.
Each of species of a pseudo-allergic small tortoiseshell (dermograficheskiya, Holodova, solar etc.) is diagnosed by the dosed influence of a provocative factor. For this purpose use , an ice cube, ultra-violet radiation with various wavelength and other tools. Assessment of results, depending on a species of a small tortoiseshell, expressiveness of symptoms and other factors is made in a few minutes or hours, the maximum term – 48 hours. Development of eritematozny rashes and a skin itch in the field of carrying out a research will be positive result of test.
Treatment of an allergic small tortoiseshell
The main link in therapy is reduction of influence of a histamine by skin tissues – it allows to reduce hypostasis and an itch considerably. For this purpose it is necessary to block H1-histamine receptors, it is reached by use of antihistamines. Now preference is given to antihistamines of the second (, ) and the third () generations. These medicines are very effective at sharp forms of an allergic urticaria, and also dermografichesky and solar pseudo-allergies. However at chronic forms of a small tortoiseshell and views with the delayed manifestation of symptoms (some types of rashes from pressure) efficiency of antihistamines is strongly reduced.
For treatment of chronic forms of pathology, and also for prevention of aggravations at the recidivous nature of allergic urticaria use medicines stabilizers of membranes of basophiles (a ketotifen ) and antagonists of calcium (nifedipine). They considerably raise a threshold of activation of corpulent cages, thereby complicating development of skin manifestations. If there is a suspicion that development a disease is caused by immunity decrease of the activity, then immunomodulatory medicines are in addition appointed. At detection of system pathology which is followed by an allergic small tortoiseshell the scheme of its treatment is developed.
Besides prescription of medicines, considerable value in therapies of this state is played by a hypoallergenic diet for reduction of load of immune system of the person. Besides, after definition of a provocative factor (the food or physical nature at a pseudo-allergy) it is necessary to take measures for its exception of life of the patient or minimization of his impact on an organism. When an allergic small tortoiseshell has prompt character and leads to angioneurotic hypostasis or anaphylactic shock urgent zhiznespasayushchy actions are necessary (injections of adrenaline and steroids, hospitalization).
Forecast and prevention
The forecast of a sharp small tortoiseshell in most cases favorable – rashes disappear within a day, without leaving any marks on skin. In the absence of repeated influence of a provocative factor the disease often any more never disturbs the person. However in case of chronic forms of an allergic small tortoiseshell the forecast in many respects depends on its type, expressiveness, observance by the patient of all requirements of the dermatologist or the allergist and correctness of the appointed treatment. Such persons need to adhere always to a hypoallergenic diet (to exclude from an egg diet, chocolate, seafood and some other products). It is extremely important to establish the reason of skin violations for minimization of its influence. If a small tortoiseshell was provoked by other disease, then the forecast in many respects depends on success of its treatment.