Allergies Skin Allergies Types of Skin Allergies Understanding Contact Dermatitis, Eczema, Hives, and Swelling By Daniel More, MD Updated on April 04, 2024 Medically reviewed by Corinne Savides Happel, MD Print Table of Contents View All Table of Contents Causes Contact Dermatitis Eczema Hives (Urticaria) Swelling (Angioedema) Various types of skin allergies can cause rashes, itchiness, and inflammation. Different conditions affecting the skin can cause itchiness and rashes, but only some are related to an allergy. However, not all rashes that itch are related to skin allergies. Insect bites and autoimmune conditions, along with fungal, bacterial, and viral infections, can all cause an itchy rash. While there may be other reasons for your rash, allergic reactions are still among the most common causes of skin rashes. This article reviews the most common skin rashes and shows pictures of each. -aniaostudio- / Getty Images Causes of Skin Allergy Skin allergies can be caused by many things, including coming in contact with certain plants (like poison ivy or poison oak) and metals or having an allergic reaction to a medication or food. Nickel, a metal found in jewelry, clothing fasteners like zippers or snaps, and cell phones, is responsible for many skin allergies. Four common types of skin allergy include contact dermatitis, eczema, hives, and swelling. Contact Dermatitis Contact dermatitis happens when the skin comes into direct contact with a substance that causes a reaction. People react to a variety of chemicals, including cosmetics, hair dye, metals such as nickel, topical medications, and dental materials. An example of contact dermatitis is a rash from poison ivy, which is extremely itchy and appears as blisters that ooze and crust after contact with plants of the Toxicodendron family. Symptoms Symptoms can include a rash, blisters, itching and burning. The rash is typically located only in the area of contact with the offending substance. Common locations include the face, especially the eyelids, neck, hands, and feet. Contact dermatitis to metals, such as in jewelry or snaps/buttons/zippers on clothing, commonly occurs on the neck, wrists/hands, piercing holes, and at the waistline. Treatment Contact dermatitis can be diagnosed through a patch test, though it can be difficult to determine the point of contact with the allergen. Contact dermatitis is treated in the following ways: Avoid the irritant.Avoid scratching the affected area (this can worsen the rash or cause an infection).Use cool compresses, anti-itch medications, and oatmeal baths to relieve itching.Apply fragrance-free moisturizer or barrier repair cream after washing. How to Prevent Skin Allergy Reactions As with other allergies, the best way to prevent a reaction is to avoid contact with the substance you're allergic to. You can minimize your risk of having a skin reaction by taking steps that include choosing clothing or jewelry carefully, covering electronic devices, or wearing long pants and gloves while working outdoors. Eczema Eczema, also called atopic dermatitis, frequently occurs before the age of 5 (although it may start in young adults) and can continue into adult life. This rash occurs most often where the skin flexes — inside the elbows, behind the knees, and in the front of the neck. In infancy, the rash most often occurs on the cheeks and/or scalp. Older children and adults typically have the rash in the skin folds of the elbows and behind the knees, although it may also occur on the face, neck, hands, feet, and back. Symptoms The rash causes severe itching, redness, oozing, and flaky scales. These symptoms can be painful and can cause changes in skin color and blisters. There are often excoriations, or areas of broken skin, from aggressive scratching. Treatment In mild cases, eczema may be treated with ointments and moisturizers (emollients). With more severe eczema, a healthcare provider may recommend prescription medication, including topical steroids and/or antihistamines. In rare cases, allergic triggers (including contact allergens and environmental exposures) may also be identified that upon removal may significantly improve rash symptoms. Courtesy of DermNet NZ Hives (Urticaria) Urticaria, commonly referred to as hives, is an itchy rash that can occur at any age. Urticaria can be acute (lasting less than six weeks) or chronic (lasting more than six weeks). Symptoms This rash appears as swelling of the surface of the skin into red- or skin-colored welts (called wheals) with clearly defined edges. These raised bumps can be of various shapes and sizes and last for minutes to hours, but not usually more than 48 hours. While it can be very itchy, a person with hives will generally not scratch enough to break the skin and cause bleeding. Treatment Mild cases of hives will likely go away on their own in a few days. To reduce itching and swelling: Use cool compresses, anti-itch cream, and oatmeal baths.Use lukewarm water and avoid rubbing with a washcloth, loofah, or mesh sponge when taking a shower or bath.Use fragrance-free soap, cleansers, and moisturizers.Do not wear tight-fitting clothing, which can irritate the area.Your provider may suggest that you take an antihistamine such as diphenhydramine (Benadryl) or cetirizine (Zyrtec). Follow your provider's instructions or the package instructions about how to take the medicine.Other oral prescription medicines may be needed, especially if the hives are long-lasting. If your reaction is severe, especially if the swelling involves your throat, you may need an emergency shot of epinephrine (adrenaline) or steroids (like prednisone). Hives in the throat can block your airway, making it difficult to breathe. DermNet NZ Swelling (Angioedema) Swelling, also called angioedema, is similar to hives, but the swelling is under the skin instead of on the surface. It can occur with hives or it may be caused by an allergic reaction. It often involves the lips, eyes, hands, and feet. Symptoms In cases where angioedema presents at the same time as hives, the swelling usually feels itchy. In cases where angioedema presents without urticaria, it can feel itchy or it may burn, sting, or cause a tingling sensation instead. In rare cases, severe swelling around the throat can block the ability to breathe. This is a medical emergency known as anaphylaxis, which requires immediate medical attention and can be life-threatening. Treatment Mild symptoms may not need treatment. Moderate to severe symptoms may need to be treated with the following: Avoid any known allergen or trigger that causes their symptoms.Avoid any medicines, herbs, or supplements that are not prescribed by a provider.Cool compresses or soaks to relieve pain. Medicines used to treat angioedema include: Antihistamines Anti-inflammatory medicines (corticosteroids) Epinephrine shots (people with a history of severe symptoms can carry these with them) Inhaler medicines that help open up the airways Seek medical help right away if throat swelling causes difficulty breathing. DermNet NZ When to See a Healthcare Provider Contact your healthcare provider right away if you have a rash that appears suddenly, spreads quickly, or is accompanied by a fever. You should also seek care if you have a blistering rash near your genitals, on or near your eye area, or in your mouth, or if a rash shows signs of infection. Summary Skin rashes can be alarming, particularly if you're having an allergic reaction to a substance you encounter in your daily life. Because there are different types of rashes, it's important to understand which type of rash you have and which treatment will work best. If you do not have a history of skin allergies, it's important to work with a healthcare provider to learn what is causing your rash so you can avoid it and prevent future reactions. 11 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Academy of Allergy, Asthma, & Immunology. Skin allergy. American Academy of Dermatology Association. 10 Reasons your skin itches uncontrollably and how to get relief. Martin SF, Rustemeyer T, Thyssen JP. Recent advances in understanding and managing contact dermatitis. F1000Res. 2018;7:810. doi:10.12688/f1000research.13499.1 American Academy of Dermatology Association. Eczema types: contact dermatitis tips for managing. American College of Allergy, Asthma, & Immunology. Eczema. Maliyar K, Sibbald C, Pope E, Sibbald G. Diagnosis and management of atopic dermatitis: A review. Adv Skin Wound Care. 2018;31(12):538-550. doi:10.1097/01.ASW.0000547414.38888.8d Medline Plus. Hives. American Academy of Dermatology Association: Hives: diagnosis and treatment. Medline Plus. Angioedema. Kanani A, Betschel SD, Warrington R. Urticaria and angioedema. Allergy Asthma Clin Immunol. 2018;14(S2):59. doi:10.1186/s13223-018-0288-z American Academy of Dermatology Association. Rash 101 in adults: When to seek medical treatment. Additional Reading Schaefer P. Acute and chronic urticaria: evaluation and treatment. Am Fam Physician. 2017;95(11):717-724. Schneider L, Tilles S, Lio P, et al. Atopic dermatitis: A practice parameter update 2012. J Allergy Clin Immunol. 2013;131(2):295-299.e27. doi:10.1016/j.jaci.2012.12.672 By Daniel More, MD Daniel More, MD, is a board-certified allergist and clinical immunologist. He is an assistant clinical professor at the University of California, San Francisco School of Medicine and formerly practiced at Central Coast Allergy and Asthma in Salinas, California. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit