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 DENOMINATION
- Allergic conjunctivitis (CA)
- Querato spring conjunctivitis (KCJV)
- Querato conjunctivitis atópica (KCJA)
- Conjunctivitis papilar giant (CJPG)
INTRODUCTION
The allergic conjunctivitis is an inflammatory illness of the ocular surface that affects approximately 25 % of the population in general with singular impact and incidence in the economic and social aspects. It can appear alone or partner to other allergic illnesses, fundamentally before the allergic rinitis.
DEFINITION AND SYMPTOMS
The allergic conjunctivitis is an inflammation of the mucous membrane conjuntival that produces itch, eritema (red eyes), intense heat of eyes, inconveniences with the light, increase of lagrimeo (tearful eyes), and sensation of fine sands on having moved the eyelids.
PRINCIPAL DIAGNOSES OF OCULAR ALLERGY
- Allergic conjunctivitis. It is the phase of ocular affectation of the allergic rinoconjuntivitis, principally it appears in the allergy to the pollen, but it can be in allergy to the mites of the domestic dust or to epitheliums of domestic animals. In contrast to other conjunctivites of allergic origin (KCJV and KCJA) it does not produce residual injuries, therefore it is important to avoid the yatrogenia (to hurt more with the medication than with the proper illness).
- Spring Queratoconjuntivitis. The spring queratoconjuntivitis KCJV is a bilateral inflammation of the conjunctive one that appears more often in the children and adolescents, she usually gives more symptoms during the spring - summers months, although in some cases it can be the whole year.
- Queratoconjuntivitis atópica. The patients with dermatitis atópica IT (GIVES) they can present injuries in the eyelids as in the rest of the skin. The conjunctive and hornlike one also they can turn out to be affected. These ocular injuries associated to it GIVES IT this is what it is named queratoconjuntivitis atópica KCJA.
- Conjunctivitis papilar giant. The conjunctivitis papilar giant CJPG is a type of conjunctivitis similar to the spring queratoconjuntivitis, but that appears only in patients who use soft contact lenses. Although less often, also they have been described after the use of hard lenses of contact and enclosed ocular prostheses. His production mechanism is not known although it has been suggested that it can be produced by an allergic answer or irritativa to deposits (antigens and/or irritants) accumulated in the lenses, or to condoms like the timerosal used in some antiseptic solutions for the lenses of contact. The chronic traumatism of the eyelid seems to be also a common agent precipitante.
- Allergic Dermatoconjuntivitis for contact. Because the skin of the eyelid is thin, it turns out to be especially capable to the dermatitis of contact (DC), both of allergic origin and of origin irritativo. When the agent etiológico affects, in addition to the skin of the eyelid, the conjunctive one, a dermatoconjuntivitis (DCJ) takes place.
MECHANISM OF THE ALLERGIC REACTION
The phenomenon of allergic inflammation is characterized by an immediate answer - consequence of a liberation IgE-Dependent on mediators of mastocitos and basófilos - followed by a simple-minded and more long phase, in which an infiltration happens at the expense of eosinófilos and other cells.
In this process, a complex interaction exists between resident cells (mastocitos, cells presenters of antigen, epiteliales cells, cells endoteliales) and cells recruited to the focus (lymphocytes T, monocitos, eosinófilos, basófilos, thrombocytes). Some and others are mediators' sources, citoquinas and quimiocinas that support and amplify the inflammatory answer.
In these complex systems we can differentiate diverse stadiums of the inflammation:
- Alergénica exhibition and sensitization, with the formation of cells Th2 interleucinas producers (IL-4, IL-5, etc...)
- Appearance of producing plasmatic cells of IgE, fixation of IgE to the cells surface efectoras (Mastocitos and basófilos) and interleucinas appearance with actions quimiotácticas of the eosinófilo and citoquinas.
- Liberation of preformed aminas of the mastocito, products of the break of the cell membran with leucotrienos appearance, prostagladinas, other direct mediators, quimocinas, citoquinas, neuropéptidos, intermediary products reagents of the nitrogen and oxygen, activation of eosinófilos with enzymes production líticos, and the expression of molecules of adherence.
- Appearance of typical symptoms in the conjunctivites, itch, equimosis, epífora, photophobia, sensation of strange body, etc...
CAUSES OF THE ALLERGIC CONJUNCTIVITES
Between the factors alergénicos that can cause allergic conjunctivites we can emphasize:
- Mites of the domestic dust: dermatophagoides, Lepidogliphus, Tyrophagus, etc...
- Pólenes, gramíneas, cupresus, pinus, platanus, betula, flutters, parietaria, sagebrush, etc...
- Aerógenos fungi, Asperguillus, would Alternate, etc...
- Domestic animals epitheliums, cat, dog, horse, hámsters rabbits, guinea pigs, mice.
- Others of professional origin as the latex, the flours, etc...
DIAGNOSIS OF ALLERGIC CONJUNCTIVITIS
The first thing that a medical specialist will realize is to gather a case history that is the history of the symptoms that there endures the patient, where the following information is obtained:
- Personal and familiar precedents of atopia (familiar allergy)
- Description of the symptoms, ocular itch, lacrimeo / epifora, photophobia, edema ó conjuntival injection, sensation of strange body, photophobia, and the association to symptoms of other organs of nasal allergy (sneezes, nasal itch, hidrorrea, nasal obstruction, presence of smell), bronchial (cough, expectoration, sibilant or shortness of breath), or cutaneous (itch, leather injuries, etc...).
- Also there will be gathered information of temporality of the symptoms: is it seasonal or perennial?
- The suspicious relations, with aero-allergens, with the work / labor, love, or others.
- Typical of the housing: rural or urban, sunny or humid...
- Presence or not of domestic animals.
In the physical exploration it will be possible to observe the conjunctive one with eritema, injuries of stone pavement, secondary injuries of cornea, etc...
COMPLEMENTARY ANALYSES
To confirm the possible causative reagents of the allergic conjunctivites the following studies can be realized:
- Cutaneous tests ó you try allergy. There are an attempt of reproducing in the skin what one supposes that it happens in the organs where the allergy symptoms take place. The skin contains the same type of special cells as the located ones in the nostrils or the lung, and that are prepared to react with the alérgenos. For it they will be proved:
- Mites of the domestic dust: dermatophagoides, Lepidogliphus, Tyrophagus, etc...
- Pólenes, gramíneas, cupresus, pinus, platanus, betula, flutters, parietaria, sagebrush, etc...
- Aerógenos fungi, Asperguillus, would Alternate, etc.
- Domestic animals epitheliums, cat, dog, horse, hámsters rabbits, guinea pigs, mice
- Others of professional origin as the latex, the flours, etc...
Skill of the Prick test for the allergy tests. It consists of realizing a small puncture with a lancet, across a drop of alérgeno (commercialized extract) deposited on the skin. It is practised usually in the internal surface of the forearm. Tests are realized for several allergens simultaneously. The skin is marked by a pen or felt-tip to identify the place of every test.
To avoid the error of a false negative or a false positive another two cutaneous tests "control" are realized with histamine and physiological whey. A skin reactivates little there will show a light reaction to the histamine (which happens also if the patient is in treatment with antihistamines, what at least one week will have to allow taking them before the achievement of the test), and therefore the results will be slightly representative. If the physiological whey provokes a visible reaction, we will be, before a skin with, dermografismo, special cutaneous reactivity (there is appreciated in the skin the drawing that we realize with a blunt object). In both cases the results of the tests will have scarce diagnostic value.
Once a small alérgeno quantity has penetrated inside the skin, in the place of the test there will break loose the reaction of the sensitive cells, there being liberated certain chemical substances that will give place to the formation of a habón sobreelevado, surrounded with an area of reddening and that it stings.
To fifteen minutes the readings of the tests are realized, measuring the size of the habón.
It is a painless and quite sure test.
Determination of entire IgE and of specific IgE. It is a skill that is realized by means of the whey extraction and in the laboratory. What measures itself is the level of specific IgE against the allergens suspicious of causing the symptoms. It is realized in addition to or instead of the cutaneous tests when it is a question of small children, or why they must to themselves prove too many allergens, or there are doubts of the etiology, or why the cutaneous tests cannot be realized (eczema, fear of the tests, etc.), or only for to confirm the diagnosis.
It tries provocation conjuntival. It is realized to confirm the diagnosis of the cause of the allergy, for it it applies the suspicious allergen to itself in one of the conjunctive ones and is compared with other one as for the possible appearance of symptoms of allergy.
eye itch
reddening of conjunctive (+ that 50 % of area)
If these criteria appear the test is considered to be positive.
It tries the patch. It is realized in the diagnosis of the allergic Dermatoconjuntivitis by contact.
It is a specific test that is applied to identify the substances that cause one the allergic dermatitis. They are applied in the back, placing small discs impregnated with small quantity of the substance or substances to evaluate. They get ready in lines and once placed they are covered with a Band-Aid. The patches are supported for 48 hours, owing the patient to continue a series of norms to prevent from faltering the results: The back is not wetted; to avoid the heat and the sudación, the area does not scratch; not to exhibit the area the light.
At 48 hours, the skin is marked first of all, the patches move back and the first reading is realized. At 72-96 hours the reading recurs.
They are realized by means of groups and in general it is begun by a panel of 29 allergens that correspond to the European standard. The allergens enter this panel more often causal of contact allergy. Also and depending on the type of suspicion panels exist for diverse professions or for groups of contactantes (cosmetics, metals, etc...).
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