In practical allergology, therapeutic interventions for this disease are reduced to the elimination of contact with provoking metals and symptomatic treatment. In case of skin forms of the pathology, the patient should abandon the use of jewelry, clothing with metal products (buckles, buckles, buttons).
If allergy is caused by cosmetics – it is necessary to completely eliminate their use. Allergic stomatitis on the background of dental fillings, installation of implants, braces is eliminated after the removal of elements based on metal alloys. Treatment of food intolerance to metal-containing products requires correction of the diet, sometimes changing kitchen utensils for cooking with ceramic or enameled.
Allergy skin disorders are facilitated by the use of local agents (ointments, gels) containing glucocorticoids. The latter effectively eliminate itching and help reduce the activity of inflammation. In severe stomatitis or angioedema, prednisone is prescribed. In rare cases with infectious complications (suppuration), antimicrobials are used. Antihistamines for this pathology have limited effectiveness, but in many patients they accelerate the disappearance of skin symptoms. Hardening and vitamin therapy are also recommended, contributing to the strengthening of immunity and correction of its activity.
Allergy to metal is registered in 7-10% of the world’s population, but a significant proportion of cases remain undiagnosed. This is facilitated by the weakness and non-specificity of the symptoms of the disease, their slow development, as well as the tendency of the pathology to spontaneously disappear. The wide distribution of the state is due to the massive use of metal products in the form of items of clothing, jewelry, household items, and dishes. Sometimes allergic reactions can cause metal, which is part of the dental and surgical instruments, cosmetics, medicines. It has been established that adults predominate among patients, whereas in children this problem is much less common. This distinguishes intolerance to metal ions from other types of allergies.
Causes of Metal Allergies
Hypersensitivity develops only to certain chemical elements from the group of metals. The causes of its occurrence have not been reliably established, the influence of environmental and genetic factors is assumed. Increased sweating or individual characteristics of the sebaceous glands plays a supporting role in the development of skin forms of this allergy. This facilitates the penetration of ions into the epidermis, which is necessary for the development of the reaction.
Not only “pure” metals can provoke intolerance, but also compounds containing them in their composition.
Most often the pathology is caused by the contact of the body with the following substances:
- Nickel. Causes a significant proportion of cases of atopic dermatitis resulting from contact with metals. Included in the composition of the alloys, from which a variety of elements of clothing, jewelry, medical instruments.
- Chromium. Widely used as anti-corrosion and decorative coating products. Penetrating into the fabric, contributes not only to allergic reactions, but also to the formation of some toxic compounds (for example, salts of chromic acid).
- Aluminum. Previously used for the production of dishes, currently its use in everyday life is greatly reduced. Aluminum salts are contained in antiperspirants and other cosmetics.
- Zinc. It is a popular metal in therapeutic dentistry, where it is used to make filling materials. Zinc compounds are part of some types of ointments and cosmetics.
Cobalt and mercury are often added to the list of elements that provoke an allergy to metal, but this is not entirely correct. When the body comes into contact with these substances or their alloys, the released ions actually cause the characteristic symptoms (irritation and inflammation of the tissues). However, they are not due to immunological processes and hypersensitivity, but the toxic properties of these elements. In its pure form, precious metals (gold, silver, platinum) rarely provoke pathological reactions.
The itching and irritation that occurs when wearing jewelry is due to the presence of additives of other substances in them – for example, copper.
Pathogenesis of metal allergy
The pathogenesis of metal allergy is based on the penetration of ions into tissues, which dissolve in water and can interact with biological molecules. Diffusion of metal particles from the surface of jewelry, clothing items and other products occurs due to skin secretions (sweat). They dissolve microscopic amounts of metal, contribute to their penetration into the epidermis and superficial layers of the dermis, so hyperhidrosis, increased air temperature and other factors that increase the production of sweat glands, lead to more rapid development of an allergic reaction.
When metal products come in contact with other liquids (saliva, lymph, blood), the dissolution process goes even faster, hypersensitivity appears earlier.
The metal ions themselves are unable to trigger immunological reactions, since they are defective antigens. However, they interact with certain proteins of body tissues, changing properties and turning them into peculiar allergens. The further course of the pathological process may be different, most often the 4th type of hypersensitivity occurs.
Reagin intolerance variants with the release of IgE and histamine are possible. Other types of reactions to metal differ only by the penetration of ions into tissues – for example, through the mucous membranes of the mouth (from crowns and fillings) or with food. In the latter case, the symptoms of the disease are almost indistinguishable from food allergic reactions.
Symptoms of metal allergy
The most common pathology is contact dermatitis, which occurs in the zone of prolonged contact with a metal product (plaque, buttons, jewelry). The first time, when the metal contacts the skin, no reactions are observed.
The duration of the asymptomatic period depends on many factors – the quality of the alloy, the level of activity of the sweat glands, sensitization of the body. Then on the skin forms a zone of redness, itching, swelling. Most often, such manifestations are found on the stomach (from the belt buckle), neck, wrists and ears (from chains and jewelry). In women, irritation can be recorded on the back and shoulders due to the metallic elements of the bra.
If symptoms are ignored and ongoing contact with a metal object, erosions and abrasions may occur on the skin surface. They are caused by combing and disruption of microcirculation processes in the affected area. Systemic manifestations (fever, general malaise) with allergies are extremely rare. Symptoms can be enhanced by direct contact of tissue fluids with metal elements – for example, during piercing, the installation of various implants. Inflammation can be exacerbated by weeping eczema and urticaria.
In dentistry, part of allergic complications after filling or implantation is due to intolerance to metallic materials and tools. They are manifested by the development of stomatitis – swelling of the mucous membrane of the mouth, the appearance of erosions and ulcers on its surface. In a sensitized body, such symptoms occur 2-3 days after medical manipulations. Some features have an allergy that develops in response to the use of metal ions with food. For example, nickel intolerance in this case is manifested by an erythematous rash in the genital area and the anus.
Complications of metal allergy
Severe or dangerous complications in case of metal allergy are almost never encountered. Presumably, some cases of angioedema after dental procedures can be explained by the intolerance of the metal-ceramic or zinc-containing filling material.
Skin manifestations of the disease may be complicated by a secondary bacterial infection caused by scratching and damage to the epidermis.
The development of bacterial asthma in metallurgical workers is considered by some specialists as one of the effects of hypersensitivity to metallic dust.
Diagnosis of metal allergy
The allergist is responsible for determining the allergy to metal. Often patients are referred by a dermatologist, to whom most patients initially refer. In some cases, the diagnosis can be difficult – the skin manifestations of the pathology are not specific, they are not always possible to associate with the effects of metallic materials.
The effectiveness and reliability of laboratory tests or test systems for the disease is very low. For this reason, an important role in determining allergy is played by questioning and studying the history, as well as indirect signs of pathology.
Identification and confirmation of the presence of hypersensitivity is performed according to the following algorithm:
- Physical examination. With the defeat of the skin revealed redness, erythematous rash, sometimes desquamation. Frequent localization – the lower abdomen, wrists, neck, fingers, earlobes, armpits. Sometimes allergic stomatitis develops – erosions, ulcerations, swelling of mucous membranes are detected in the oral cavity.
- History taking. During the interview, the doctor finds out with what objects (items of clothing, jewelry) was the contact of the affected skin in the last few days. The specialist specifies how long the patient visited the dentist and for what reason (with inflammation of the oral mucosa). If a food metal allergy is suspected, the patient’s diet is studied before the pathology develops.
- Allergic tests. Specific skin tests with standards of allergens for this type of intolerance is not developed. A variant of a provocative test can be used, in which the patient is in contact with the metal for a while (from several hours), then a day later an examination is made with a specialist. The food type of allergy can be determined by means of an elimination test – eliminating products with a presumably high content of metal ions from the diet.
In determining the pathology take into account that the reaction can cause contact not only with free metals, but also with their compounds. The latter may be part of cosmetics, antiperspirants, some drugs. Differential diagnosis of the disease is carried out with contact dermatitis of a different etiology and other inflammatory skin pathologies.
With the defeat of the mucous membranes of the oral cavity exclude stomatitis of infectious genesis. Food types of metal intolerance are almost indistinguishable from the usual food allergies, only some of the options (for example, nickel hypersensitivity) have clinical features.
Forecast and prevention of metal allergy
The prognosis of metal allergy is favorable, the disease rarely leads to a serious condition or complications. There may be certain inconveniences associated with the need to avoid contact with metal substances or cosmetics and medicines based on them. Pathology imposes restrictions on the list of dental procedures available to the patient, there are special requirements for the materials used for this. In the diet should be avoided canned foods, especially in metal containers.
There is no specific prevention of allergies, there are only general recommendations – hardening, providing the body with vitamins and trace elements, avoiding prolonged wearing of products from non-precious metals.