Allergic contact dermatitis

At a glance

  • In allergic contact dermatitis (a contact allergy), the body overreacts to a certain substance.
  • This typically causes skin reactions such as a rash, swelling and itching.
  • The main thing to do is avoid contact with the substance that triggers the reaction.
  • Contact allergies are usually treated with steroid creams, ointments or solutions.


Photo of a hairdresser styling a woman’s hair

A number of chemical or herbal substances can irritate the skin. Redness, burning or itching are normal skin reactions, for instance, to harsh cleaning agents.

Allergic contact dermatitis (sometimes simply called “contact allergies”) is different, though. Here the immune system overreacts to certain substances – sometimes to very small amounts – that generally don’t cause major reactions. Common examples include certain metals, scents and latex rubber.

Contact allergies can lead to severe skin reactions. Unlike with many other kinds of allergies, the reaction doesn’t occur immediately, but usually after one to three days. And contact allergies develop gradually over a long period of time, as a result of repeated contact with the substance that triggers them. Some people are then no longer able to carry on doing the same kind of work as before.


Contact allergies cause (dermatitis). The typical symptoms include:

  • swelling,
  • itching, and
  • dry skin.

On light skin, you can usually see a reddish rash – often without clearly defined edges. On dark skin, the affected area tends to be dark purple to dark gray in color. It is also typical for small bumps (papules) to develop on dark skin. The skin in that area usually becomes thicker and rougher, too.

In severe allergic reactions, the skin may hurt and feel tight. Blisters might form as well. If the blisters burst, the skin “weeps” (oozes a fluid), scabs form and then flake off.

At first, the symptoms affect only the area of the body that comes into contact with the trigger. This is often the hands, particularly the fingers and backs of the hands. Other areas that are often affected include the face (especially the eyelids and lips), the neck, lower legs and feet. The severity of the allergic skin reaction will mainly depend on which substance the skin came into contact with, and for how long.

In contact allergies, allergic reactions can also later occur in other parts of the body that didn’t come into contact with the substance that triggered the .


Substances that commonly trigger contact allergies include the following:

  • Metals (e.g. nickel and cobalt)
  • Latex rubber
  • Adhesives (e.g. the sticky substances in plasters)
  • Plants (e.g. chamomile and arnica)
  • Scents (in cosmetics such as lipsticks, perfumes and soaps)
  • Cleaning agents and solvents
  • Essential oils
  • Medications that are applied to the skin

The body already makes antibodies to fight the trigger (allergen) the first time it comes into contact with it. This makes the skin react more sensitively to the substance when it comes into contact with it again. Noticeable symptoms only start appearing over time, after repeated contact with the substance. For instance, hairdressers may develop contact allergies to substances that they touch every day, such as hair dyes or perm solutions. Some people are generally more prone to allergies. They may develop contact allergies in a shorter amount of time.


About 8% of all adults have a contact . They are more common in women than in men. Contact allergies are responsible for 10% of all occupational (work-related) diseases. They commonly affect hairdressers, beauticians, nursing staff, bakers, office workers, metalworkers and bricklayers.


Contact allergies usually first arise in adulthood. The symptoms often go away if they are treated and the triggers are avoided. But contact allergies might also develop into chronic contact dermatitis. The skin then becomes thick and hard, with painful cracks.


It isn’t possible to determine whether or not someone has a contact based on the symptoms alone. But allergic rashes are often a bit different from rashes that are caused by other things. For instance, a rash without clearly defined edges is more likely to be a sign of an allergic reaction. And allergic rashes often occur on various parts of the body.

The doctor will ask you which substances you came into contact with in the days before the symptoms appeared, and whether you have been repeatedly exposed to certain substances in the past.

A patch test can be done to find out whether it is actually an allergic reaction. This involves placing the substances on your skin with the help of patches that are stuck on your back for one to two days. If a rash appears where a patch was, you're probably allergic to that substance. On light skin, the rash can usually be seen as a red area. On dark skin, it is more likely to be darker, and the skin may be bumpy or thicker, which the doctor can feel. It can be easier to see smaller bumps if the doctor shines a light on the area from the side.

Patch tests may actually lead to the development of contact allergies, though. So it’s all the more important that the doctor is well informed about contact allergies and is careful when choosing which substances to use in the test.


Allergic skin reactions are usually treated with steroid creams, ointments or solutions.

But the main thing to do is avoid contact with the substance that triggers the reaction. For instance, if you're allergic to nickel you should make sure that jewelry, buttons or belts that touch your skin don't have nickel in them.

If you can't avoid contact with the substance at your workplace, things like gloves or protective clothing can help. You may also have to switch to other activities at work. If you're believed to have a work-related contact , it’s a good idea to have your dermatologist or company doctor inform your employer’s liability insurance. The insurance will cover certain costs, like the costs of protective measures, if the is recognized as being work-related.

Further information

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German health care system and find a suitable doctor. You can use this list of questions to prepare for your appointment.

Biedermann T, Heppt W, Renz H et al. Allergologie. Berlin: Springer; 2016.

Deutsche Kontaktallergie-Gruppe (DKG). Leitlinie Kontaktekzem (S1-Leitlinie). AWMF-Registernr.: 013-055. 2021.

Diepgen TL, Ofenloch RF, Bruze M et al. Prevalence of contact allergy in the general population in different European regions. Br J Dermatol 2016; 174(2): 319-329.

Fonacier L, Bernstein DI, Pacheco K et al. Contact dermatitis: a practice parameter-update 2015. J Allergy Clin Immunol Pract 2015; 3(3 Suppl): S1-39.

Rashid RS, Shim TN. Contact dermatitis. BMJ 2016; 353: i3299.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on February 1, 2024

Next planned update: 2027


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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