Contact allergy is also known in medicine as allergic contact dermatitis or contact dermatitis. All terms mean the same condition.
What is a contact allergy?
Contact allergy, allergic contact dermatitis, or contact dermatitis is an allergic skin reaction that occurs when the skin comes into direct contact with an allergen. Typically, the allergens are substances that the affected person deals with on a regular basis. This can be in the private sphere as well as frequently in professional life. Artificially produced substances and natural substances such as plants or plant parts can be considered as allergens. The contact dermatitis does not occur at the first contact with the allergen. The formation of eczema occurs as a delayed reaction of the immune system only some time after contact. In the therapy of contact dermatitis, the avoidance of contact with the triggering substance is the decisive factor. This not infrequently leads to the fact that the previous profession or a long-standing hobby can no longer be practiced.
Causes
The causes of a contact allergy are found in a hypersensitivity to substances that can cause an allergic reaction through direct physical contact. In this context, the allergy-triggering substances are different for each person. Mostly, however, it is substances such as flavorings in make-up or cosmetics, hair dyes and tanning agents. But also cobalt chloride, nickel sulfate, preservatives, detergents, medicines, solvents and plasticizers can trigger a contact allergy. But it is not only chemical substances that cause contact dermatitis in some people. Plants, such as arnica and marigolds, can also lead to allergic reacton, similar to hay fever. In women, costume jewelry with nickel content often leads to allergic contact dermatitis. This is then described separately as nickel allergy in more detail. Furthermore, various occupational groups may suffer more frequently from contact allergy. Beauticians: solvents, make-up, cosmetic articles, perfume
Hairdressers: hair dye, hair spray, hair shampoo
Bakers and confectioners: hypersensitivity to flour
Craftsmen: cement, paints, synthetic resin, adhesives, silicone
Janitors or cleaning professionals: cleaning products, cleaning fluids, room sprays
Symptoms, complaints and signs
A contact allergy initially causes skin changes. Within one to three days after contact with the allergen, the skin turns red and swells in the affected area. In most cases, weeping blisters or wheals form, which in turn form crusts and scales. This is accompanied by increasing itching and burning. In case of prolonged contact with the allergen, chronic contact dermatitis may develop. In this case, a callus forms, which hurts when touched and can break open after some time. Finally, a chronic skin disease sets in, through which the affected person permanently suffers from pain, itching and a strong feeling of discomfort. In rare cases, the mucous membranes are also affected. In such cases, redness, swelling and rarely ulcers occur in the area of the mucous membranes. If the respiratory tract is involved, breathing difficulties, difficulty swallowing and acute pain reactions are possible. Occasionally, contact allergy may cause an asthma attack. Symptoms of contact allergy can occur all over the body. Typically, the hands, face, chest area, neck, throat, and ankles are affected. The skin reactions can spread and sometimes affect large areas of the skin. If the allergy is treated early and the allergen is avoided, the symptoms usually subside within a few days.
Diagnosis and course
Schematic diagram showing the anatomy of the skin and the causes and symptoms of allergic skin eczema. Click to enlarge. The development of contact allergy occurs in two stages. The first stage is called the sensitization phase. In this phase the body comes into recurrent contact with the allergen. The exact process and the influencing factors have not been fully researched. However, it is certain that the process of sensitization corresponds to the processes during the defense against infections and thus the basics are present in every person. During sensitization, special cells are activated in the lymph nodes, which then multiply.In the second phase, the trigger phase, renewed contact with the allergen leads to the corresponding symptoms. The skin reactions typical of contact dermatitis usually occur two to three days after renewed contact with the trigger. This temporal shift often makes it difficult to assign the disease to a specific substance. In contact dermatitis, the same symptoms develop as in other eczema diseases. At the beginning of the disease, there is redness and swelling of the affected skin area. In the further course, blisters and nodules, the so-called papules, form. Later, the area dries up and becomes scaly. If contact with the allergenic substance is not avoided, the contact allergy can also take the course of a chronic eczema. Here, the skin texture becomes coarser and cornifications, so-called hyperkeratoses, and fissures form.
Complications
Various reactions or symptoms may occur with contact allergy. Generally, complications can be avoided if the affected person completely avoids contact with the substance in question. However, this can significantly limit the patient’s life and is also not always completely possible. For this reason, contact allergy often significantly reduces the quality of life of the affected person. In the process, reddening of the skin occurs and itching stimuli appear in various parts of the body. As a rule, the itching intensifies when the patient scratches the respective area. Papules may also form, which also lead to reduced aesthetics. In many cases, there are inferiority complexes or decreased self-esteem due to the symptoms. Most patients are ashamed of the complaints and therefore no longer actively participate in life. Avoidance of a particular ingredient can also lead to depression and other psychological complaints. Contact allergy can be limited with the help of medication. However, a complete cure is often not possible. Complications do not occur during treatment and the life expectancy of the affected person is not reduced by the contact allergy.
When should you go to the doctor?
If the typical symptoms of contact allergy limit the quality of life, a doctor should be consulted. Often discomfort can be avoided by avoiding contact with the triggering substances. Medical advice is needed if the causes of contact allergy are unknown or if unusual symptoms and discomfort occur. Especially redness and itching are warning signs that require clarification by the doctor. So are pustules and other skin changes as well as shortness of breath, fever and circulatory problems of all kinds. People who perceive any pustules or redness as cosmetic blemishes should consult their family doctor. Other contacts are the dermatologist or an internist. An allergist may also be consulted. With children, it is best to see a pediatrician for the above symptoms. Severe shortness of breath and serious cardiovascular symptoms are a medical emergency. The affected person should immediately call 911 or go to the nearest hospital. If there is a loss of consciousness, the emergency medical services must be alerted. The contact allergy is then treated in a hospital and the patient is provided with an allergy passport and emergency medication.
Treatment and therapy
Contact allergy is usually treated with ointments containing glucocorticoids when acute. Alternatively, UV therapy may also provide relief. This is mostly used when there are other conditions in the patient that make the use of glucocorticoids impossible. The treatment of contact dermatitis is only promising if the allergy-causing substance is avoided at the same time. Therefore, the most important thing in the therapy of contact dermatitis is to find its trigger. In some cases, despite treatment and avoidance of contact with the allergen suspected as the cause, the eczema does not improve even after some time. The prick test is an allergy test to check for allergic reactions to pollen or animal hair, for example. In this test, possible allergic substances are dripped onto the skin, which is then lightly pricked with a lancet. After 20 minutes, the redness of the skin and the size of the wheal are assessed.It must then be assumed that there are other substances that trigger the allergy. In this case, it must be investigated which other substances could be involved. In the case of recurrent contact allergies, the cause may be a failure to avoid contact with the allergen. In individual cases, it is often difficult to avoid the allergen if contact with it is necessary almost daily, for example, for professional or private reasons. It is also possible that the complaints are not due to a pure contact allergy. Sometimes contact allergy and other allergic reactions or other forms of eczema occur at the same time, making diagnosis and treatment more difficult.
Outlook and prognosis
The prospects of finding a complete cure for contact allergy (contact dermatitis) vary. Prospects for cure may be present if the cause of the contact allergy can be determined. If this is the case, professional treatment can take place. In the course of this, the effort must be to avoid or eliminate the causative agent of the contact dermatitis. This is often not possible, or only possible to a limited extent. In most cases, contact dermatitis persists throughout life. The eczema can be kept in check by administration of corticosteroids. In chronic contact allergies, irradiation with UV light can be helpful. Especially on the hands, this can initiate improvement. However, because contact dermatitis involves the immune system, the prognosis is usually not as positive. Contact with the allergen often cannot be completely avoided. The chances of cure depend on several parameters. If the triggering substance can be completely eliminated, healing of contact dermatitis is possible. Contact allergy depends on the presence of the allergen. In the case of occupational contact dermatitis, a change of occupation may be advisable or mandatory. For mild allergy symptoms, cortisone ointments may suffice. In the case of severe and chronic skin dermatoses, however, the affected skin may become more susceptible to bacterial or fungal attack. It is affected by infections significantly more often than healthy skin.
Prevention
According to the current state of research, it is not possible to prevent the development of contact allergies. It is never foreseeable which person will react to which substance by developing contact dermatitis. Those who are prone to allergies should try to protect their skin with protective gloves and clothing, especially when handling cleaning agents or disinfectants. In addition, the use of pH-neutral products is recommended. Many allergen-rich products from daily life, such as soaps, deodorants and fabric softeners can be replaced by other products. However, the development of a contact allergy cannot be completely ruled out.
Aftercare
The attending physician informs sufferers about goal-oriented behaviors in the context of the initial diagnosis. Beyond that, however, he only acts in case of acute problems. The patient bears a high degree of personal responsibility for freedom from symptoms. Scheduled follow-up examinations, as known from tumor diseases, are rare and are related to recurrent, severe complaints. Especially in the beginning, it can be time-consuming to correctly determine all triggers. Complications are present when the skin is affected over a long period of time. Often, only acute treatment with antibiotics can help. Knowledge transfer is a particularly important part of everyday support. The affected person learns how to behave in the event of an allergic reaction. Ointments and tablets should be kept in stock. The best way to avoid the symptoms is to prevent them from occurring in the first place. To do this, the patient must avoid the typical triggers or remove them from his or her environment. Aids such as gloves and clothing prevent infections. The patient’s actions are decisive for the success of the measures.
What you can do yourself
The best form of self-help for contact allergy is to identify the allergen and avoid it as much as possible. If the search for the trigger proves difficult, an allergy diary can help. In this diary, the affected person records his or her activities and the symptoms observed. The records must be kept for several weeks and then often reveal statistical correlations between a particular activity and an allergic reaction.These evaluations help the treating physician to narrow down the possible allergen. Allergic reactions to fragrances and other excipients in cosmetic products and household cleaners are widespread. In this case, only care products labeled as “hypoallergenic” should be used. There is now a wide range of both care products and decorative cosmetics that have been formulated with the special needs of allergy sufferers in mind. In the case of an allergy to cleaning agents, it is usually sufficient to wear gloves when performing household chores. If a contact allergy indicates that there is a risk that the patient will no longer be able to perform his or her current occupation, it is extremely important that the patient seek not only medical but also legal advice. An affected person should promptly contact his trade union or a specialist lawyer for social law. In larger cities, charitable institutions often offer free legal advice for people in such situations.
