Rash from allergy

introduction

Skin rashes caused by allergies belong primarily to the so-called delayed type (type IV) allergic reactions, the Allergic contact eczema.

In their appearance they belong to the group of Eczema on. This means a non-infectious, itchy inflammatory reaction of the skin. On the one hand, this can occur in the form of allergic contact eczema direct contact with an allergy-causing substance arise, but also one Triggered by repeated smaller doses of the respective substance is possible.

On the other hand, the skin can also react to an allergenic load absorbed through the lungs or the gastrointestinal tract react too.

Also independent dermatological clinical pictures like the Neurodermatitis or psoriasis become influenced by allergic loads. Furthermore, it is mainly about the skin rash caused by allergies, in the sense of allergic contact eczema.

Not every allergy sufferer reacts to the causal foreign substance in different ways. Whereas with a mildly pronounced allergy, the affected person typically only develops one skin rash severe allergic reactions can also appear as life threatening Manifest the situation. In this context one speaks of a so-called anaphylactic reaction. In addition to the skin rash typical of an allergy, those affected often also suffer from one Upper respiratory tract impairment.

Shortly after the Allergen contact, the affected person's nose begins to run. In addition, the upper airway can pass through a allergy-related swelling of the Mucous membranes narrow. Also acute Inflammation of the conjunctiva with watery and itchy eyes are not uncommon with an allergy. Depending on the extent of the allergic reaction, the Gastrointestinal tract be affected.
For this reason, in addition to the typical rash in some allergy sufferers diarrhea and nausea. In addition, general symptoms such as fever, fatigue, Exhaustion and sleep disorders observed particularly frequently.

The allergic rash must also be divided into different classes. As the largest organ in the body, the skin the outer protective coat. In addition, the skin surface has a certain signaling function, because changes in the skin area can be used to deduce internal processes.
In terms of contact with non-infectious foreign substances (allergens), the skin plays a crucial role as a helper and ambassador for the body's own immune system. A rash that develops as a result of an allergy can therefore be limited to a certain region (local rash) or affect a larger area of ​​skin.

You can also Rashesthat through a allergic reaction take on a different color. Depending on the causal foreign matter and individual immune response, the rash may be reddish to brown in color. Read on here: Rash from milk

Often rashes are localized near the genital area. Read more on the topic Rash in the genital area

causes

As with other allergic reactions, the cause of a skin rash from allergy is a sensitization of the body to substances that are actually harmless. These are known as Allergens.

This sensitization takes place in two phases, whereby the first phase remains without symptoms. During this first contact, the body's own immune cells develop, which trigger an immune reaction when the substance in question is recognized again.

During the second contact, this immune reaction then e.g. the contact eczema. The body, in this case the defense cells in the skin, treat the substance as a threat.

The T cells (see: white blood cells) are primarily responsible for this faulty reaction. Once they are sensitized to the apparently harmful allergen, each time they come into contact, they release messenger substances such as histamine for an inflammatory reaction.

This process must be distinguished from what is known as toxic or irritative contact eczema, which occurs when the skin is overloaded with actually harmful substances. In the case of allergic contact eczema, it is actually harmless substances that trigger the reaction. Very often these are metals such as nickel or chromate, but also fragrances and preservatives, latex and rubber products or various cosmetics.

A food allergy can also be a trigger, and the rash can often be more diffuse. If the rash occurs mainly after consuming milk and dairy products, you may have a milk intolerance. Read more about this at: Rash from milk

Another trigger for allergy-like symptoms can be so-called pseudoallergies, such as be the sweat allergy.

For more information on possible causes of the rash, also check out our article:

• Rash causes
• Cross allergy
• Tomato rash
• Symptoms of a nickel allergy

diagnosis

The diagnosis is made mainly because of the determined skin findings in combination with the anamnese.

However, it can be with one prolonged professional awareness to be difficult, the relationship with the triggering substance or time to manufacture. In addition, even with the help of a skin biopsy and subsequent analysis, it is not possible to tell whether the trigger is due to the skin change itself allergic or toxic / irritative was.

However, indications of this can be found very well with common allergy tests (see: main article allergy diagnostics). This includes the Patch test (or Patch test). Be there potentially allergenic substances with the help of special plasters applied to the back. A possible skin reaction can then, usually after 48 or 72 hours, can be read. When used correctly, a large number of allergens can be recognized or excluded.

Frequencies

The risk of developing a rash due to allergies in Central Europe is estimated to be around 15%.

The most frequently affected parts of the body are hands, genital and anal areas and the face.

Also read: Allergy on the face- what's behind it?

Symptoms

The rash caused by an allergy usually runs in different phases.

At the beginning there is only one light red discoloration of the affected area.

In the further course then it comes to one Swelling of the tissue due to water retention (Edema). This usually happens within the first 6 hours. Here you can itching, Burn and Pain occur.

It comes through the water that has built up in the layers of the skin within the first 12-24 hours to the Tearing of the skin cell associationwhat oozing blisters arise.

After about 3 days begins the Reaction to regress. This initially forms Crusts and scales from the burst vesicles until it heals.

Read more about the topic here: Blistered rash

If there is no one-off reaction, it happens always new contact with the substance causing the allergy, forms chronic allergic contact eczema out. This occurs frequently with occupational stress where avoiding the triggering substance is difficult.

With a longer load, the Swelling and blistering are much less pronouncedHere is a increasing cornification and coarsening of the skin in the foreground, which subsequently become a very chapped skin leads.

therapy

As an active ingredient against the skin reaction comes mainly Cortisone for use. This is applied to the affected areas and curbs the excessive immune reaction of the body. It is important to refer to one of the symptoms suitable carrier substance to pay attention. For example, a more watery preparation should be used for a weeping rash, and a greasy preparation for a dry rash.

To the allergic trigger mechanisms turn off and above all the Relieve itching, can Antihistamines can be used. These can be applied locally as an ointment or systemically as a tablet. Can also be a UV light therapy, which also inhibit the immune reaction, help.

With inflammation of the skin there is always the risk that Bacteria penetrate the skin's barrier and to one additional bacterial infection to lead. To prevent this, you can disinfectants can be used.

In rare, severe cases, there is still the option of Calcineurin inhibitors (e.g. tacrolimus) to resort to.

prophylaxis

The simplest and most effective form of Preventing an allergy-related rash, consists in the Avoidance of the allergen.

There are many jewelry and watches, e.g. also without nickel content. In the field of cosmetics, too, there are now many particularly sensitive (hypoallergenic) Products.

forecast

A one-time allergic rash usually heals without consequences.

Even if the skin appears intact again afterwards, a Disruption of the skin barrier stay back. This can promote further skin reactions and to one faster and stronger reaction to renewed contact with the allergen.

The basic awareness for an antigen mostly stays for life consist. There is no possibility of desensitization, as with other allergies.

Should the Raising awareness in the workplace should have been done Report to the respective trade association respectively. Allergic contact eczema is common in many industries recognized as an occupational disease.

Rash: allergy forms

In most cases, the skin is the first organ to come into contact with a non-infectious foreign substance (technical term: Allergen) responds. A distinction must be made between different forms of this reaction. Besides the Urticaria and the well-known Neurodermatitis counts the so-called Contact eczema the most common allergic skin reactions.

Contact eczema

The so-called contact eczema (contact allergy; contact dermatitis) is an oversensitive reaction of the skin surface to direct contact with a certain foreign substance. Shortly after the allergen contact, red, swollen, oozing and / or itchy areas develop on the affected skin area.
This rash, which occurs as a result of an allergy, can also be accompanied by the formation of blisters and / or flakes. Contact eczema as a special form of rash as a sign of allergy is quite common and can have a wide variety of triggers.

A classic example of an allergy that leads to the development of contact eczema is the so-called nickel allergy. But other substances, such as fragrances, preservatives, cleaning agents and tannins, can also lead to an allergic skin reaction. In the case of contact eczema, however, it must be noted that it does not always have to be an allergic skin reaction. Non-allergic contact eczema can range from irritative symptoms (skin irritation) to toxic reactions (severely damaged skin). Contact eczema that occurs in the course of an allergy is usually found in the skin area where the allergen contact took place. In addition, this allergy-related rash can also be caused by internally ingested non-infectious foreign substances.

Read more on this topic at: Contact dermatitis

causes

The hypersensitivity of the skin surface that exists in this form of allergic rash develops over time through repeated contact with the causative agent Allergen. Within the organism, the allergen triggers a so-called immunological sensitization out. The body's immune system reacts so exaggeratedly to the allergen that an allergy-related rash develops. In the case of contact eczema, a number of possible foreign substances come into question.

To the most common causes for the development of such an allergy-related rash include:

• Nickel (mainly in costume jewelry, watches, glasses, buttons, zippers, rivets)

• Cobalt chloride (especially in buttons and zippers)

• Chromium salts (in leather)

• Fragrances (in cosmetics, candles and food)

• Phenylenediamine (in hair dye)

• Preservatives

• Tannins

• cleaning supplies

Symptoms

At a Contact eczema As a special form of allergy-related rash, the symptoms are usually confined to the skin.Only in the rarest of cases do those affected develop additional symptoms. Especially the appearance of Asthma attacks is rather rare with a pure contact allergy.

Typically, the rash forms in an allergy to the Skin areathat deal with the allergenic substance in immediate Contact was standing. However, starting from this point of contact, the rash can spread to other areas of the skin. In this context one speaks of a so-called Scatter reaction.
Both the exact location of the rash and its shape can, under certain circumstances, provide an indication of the underlying allergen. Contact dermatitis typically manifests itself as an indistinctly delineated one local reddening of the skin, the little one Vesicles may have. In addition, this form of allergy-related rash can be more pronounced itching (Technical term: pruritus) go hand in hand.

Allergic hives

In addition to contact eczema, the so-called Hives (Urticaria) is the most common type of allergic rash. Such a skin reaction occurs whenever certain Inflammatory cells activated in the skin and the messenger substance histamine pour out.

causes

Usually only a few are found in healthy human skin Inflammatory cells. Especially the so-called Mast cells play a crucial role in the development of allergy-related rashes. If an allergy sufferer comes into contact with the allergen, these mast cells are activated and different ones are stimulated inflammatory messengers, especially histamine.

After it is released, the messenger substance histamine can pass into the surrounding tissue and attach to certain receptors on the surface of the smallest blood vessels. This gives the Blood vessels the signal to join expand. In addition, the messenger substance histamine mediates the increase in Permeability the vessel walls. In this way, more fluid can diffuse from the blood vessels into the surrounding tissue. This causes small ones to appear on the skin surface of the affected person Wheals, known as hives.

Symptoms

Although the triggers for this form of allergy-related rash can be varied, the affected people experience typical symptoms. Shortly after contact with the allergen, small to medium-sized wheals appear on the surface of the skin, which appear as a reddened skin rash. In addition, local swellings can occur in the deeper layers of tissue (so-called angioedema).

The development of an allergic hives is announced in most cases by an annoying, very pronounced itching. In addition, with this form of allergy-related rash, it can often be observed that the itching increases significantly in intensity in the evening hours but steadily decreases over the course of the day. Shortly after the itching occurs, the typical small wheals, which are irregularly delimited by a red border (see also: Rash with wheals). In the presence of an allergic hives, so-called angioedema can also develop in the area of ​​the lips and eyelids. In the case of an acute allergy-related rash, the itchy wheals usually go away within 24 hours. Nevertheless, depending on the severity of the allergy, the hives can regularly flare up up to six weeks after contact with the allergen.

diagnosis

The diagnosis of a rash that may be related to an allergy is carried out in several steps. In particular, the detailed doctor-patient discussion (briefly: anamnesis) plays a decisive role in this context. During this conversation, the patient concerned is asked about the occurrence of the rash. The doctor asks the patient how long the current symptoms have existed and whether such skin changes have been observed at an earlier point in time.

In addition, the person concerned should consider whether there is possibly a connection between the Appearance of the rash and external factors could give. In addition, the patient is asked about other diseases and / or allergies. Especially people who have a so-called atopic disease have, for example bronchial asthma, tend to develop one or more allergies.

Also internal diseases, acute or chronic infections and medications that are taken regularly (especially pain relievers and anti-inflammatory drugs) play a crucial role in the diagnosis of skin rashes that may be related to an allergy. If an allergic reaction is suspected after the doctor-patient conversation and examination of the rash, an allergological test should be considered. Also one Blood test, which searches for specific antibodies of the so-called IgE type, can be useful.

therapy

The treatment of a rash that occurs as a result of an allergy depends on both causative allergen, as well as according to the severity of the skin appearance and possible accompanying symptoms. An acute rash usually disappears completely within a few weeks, even without medical intervention. During the healing phase, the formation of the wheals can usually be prevented by giving a so-called Antihistamine inhibit. Only in very pronounced cases, which are then also accompanied by other complaints, do further therapeutic steps need to be initiated.

For the treatment of allergic contact eczema are especially suitable Glucocorticoidsthat can be applied to the affected skin areas in the form of ointments or creams. These medicines help with the typical allergic skin reaction Relieve itching and to positively influence the healing process. Also cold, damp envelopes are particularly suitable for treating acute skin rashes caused by an allergy. In addition, treatment consists of a rash that occurs as a result of an allergy Avoidance of the causative allergen.

Skin reaction in babies

Even in a baby, rashes are not uncommon. In most cases, acute rash in the baby is related to a bacterial or viral infection. Babies and toddlers are particularly prone to developing a rash on the face and trunk of the body when they are infected with the flu virus. An allergy-related rash can also develop in the baby. The actual causes (allergens) for the development of the skin changes can be very different.

Since a baby's skin is still very sensitive, some detergents or additives in children's clothing can lead to allergic rashes. In addition, a food intolerance (allergy) in a child with an acute skin rash without other symptoms that indicate an infection should always be excluded.

Read more about this under: Rash on baby such as Detergent allergy

Home remedies

A rash that occurs as a result of an allergy does not always have to be treated with highly potent drugs. In particular, the accompanying symptoms associated with the allergic rash can often be solved with home remedies effectively alleviate. Moist chamomile compresses can, for example, help to quickly and reliably relieve the itching that is typical of an allergic reaction. When using this home remedy, however, it must be ensured that the heated chamomile has to cool down before it is applied to the affected area of ​​the skin. Otherwise there is a risk of painful scalding. It also counts Nettle stock one of the most popular home remedies for allergy-related rashes. Affected people can soak a clean linen cloth in the nettle stock and leave it on for a period of ten to twenty minutes itchy skin place. This home remedy reliably helps to relieve the itching that is typical of the rash.

Also simple fatty cream can help alleviate the symptoms and positively influence the healing process. However, when using this home remedy, care must be taken to just that pH skin-neutral creams, without fragrances and preservatives.

Another popular home remedy for a rash that occurs as a result of an allergy is yogurt. If this is applied several times a day to the affected skin areas, it relieves the itching, promotes the healing process and reduces the formation of wheals.

Many people who regularly suffer from allergic skin changes swear by the use of Coriander leaves. To make this home remedy, fresh coriander leaves must be grated and applied to the itchy areas. The itching typical of an allergic skin reaction noticeably diminishes within a few minutes.

If particularly large areas of skin are affected by a rash that occurs in connection with an allergy, then with Wheat bran offset Bath water develop a soothing effect. In addition to relieving itching, this home remedy has a calming effect on the damaged skin and promotes its ability to regenerate. The time it takes for the skin changes to completely subside can be significantly shortened in this way.

You can read more information on this topic here: Home remedies for a rash

Medication

While less pronounced allergic skin rashes usually heal without medical intervention without consequences severe rashthat occurs in connection with an allergy, usually drug treatment.

Especially medication that Glucocorticoids (e.g. Cortisone) are often used in the treatment of itchy skin changes. Mainly in the form of ointments or Creamswhich can be applied locally to the affected skin areas, help to effectively relieve typical itching. Other drugs that help to heal the allergic reaction quickly are so-called Antihistaminesthat counteract the effect of the allergy messenger substance histamine.

Duration

The duration of a rash that is related to an allergy depends on both Expression, as well as according to the underlying root cause. How long the allergic rash ultimately lasts also depends on when the causal allergen can be identified. As soon as the responsible allergen is identified and avoided by the affected patient, the rash that occurs as a result of an allergy persists for a period of about 14 days. However, the itching that is typically associated with skin changes can be relieved quickly and effectively with home remedies. For this reason, the question of how long the rash lasts plays only a subordinate role for many sufferers.