An Overview of Skin Allergies By Pat Bass, MD - Reviewed by a board-certified physician. Updated September 13, 2016 Skin allergies can be very annoying and bothersome. While all the conditions leading to skin allergy cause red, itchy skin, there are a number of differences in the causes as well as treatments and side effects.What Are Skin Allergies?Skin allergies are one of the many different skin conditions that may impact you. At a basic level, skin allergies are an allergic reaction to a normally harmless substance. Your immune system normally fights a foreign substance and removes it from your body. When the immune system sees a substance as foreign and reacts, you can develop an allergic skin rash. When your body interacts with one of the triggers mentioned below, you develop a reaction to the trigger that most others do not and you end up with symptoms.Common Signs & Symptoms of Skin AllergyWhen you experience a skin allergy, you might experience a combination of the following: Article Atopic Dermatitis Versus Contact Dermatitis: How to Tell the Difference Article Love Essential Oils? Make Sure You're Not Allergic rashitchingrednessswellingraised bumpsscaling or flaking of skincracked skinWhile you would expect to develop similar symptoms if you come into contact with the trigger again, you may develop any of these symptoms with any exposure.Common Causes of Skin AllergiesA number of different triggers can lead to skin allergy, including:latexpet danderpoison ivy or poison oakcold or hot temperaturespollensunlightwaterfoodinsectsdrugsWhat Are Common Allergic Skin Conditions?A number of different allergic skin conditions may impact you, including:Eczema. Also referred to as atopic dermatitis, this skin condition most frequently starts in the first couple years of life, but it can first appear in an adolescent or adult. In the first several months of life the rash may occur almost anywhere, but most commonly occurs on the extensor surfaces (e.g., knee and elbow), chest, cheeks, and scalp—areas where the child is able to scratch and further irritate the skin. The rash is often red, itchy, scaly, and crusty. It may also ooze and generally spares the diaper area.In older children, adolescents, and adults, the rash most commonly occurs in the flexural areas (behind the knees and opposite area of the elbow). Scratching and rubbing of the skin may result in an exaggeration of normal skin markings and abnormal pigmentation called lichenification. This may result in a leathery bark-like appearance that is often referred to as a “atopic dirty neck.” The rash can also occur anywhere on the eyebrow, hands, neck, and face.Contact Dermatitis. This reaction is most commonly due to an irritant, but an allergic reaction is also possible. Inflammation of the skin results after contact between an allergic trigger substance and your skin. Article Most Common Location for Eczema Article Atopic Dermatitis Treatment for About $10 A Month While the rash can look very similar to eczema, the rash normally only occurs where the skin has had contact with the offending agent. The face, eyelids, neck, hands, and feet are commonly affected areas. While poison ivy, poison oak, and poison sumac are the most common causes of allergic contact dermatitis, nickel allergy (commonly seen in jewelry), cosmetics, antibiotic creams, rubber, and the chemicals on shoes also commonly lead to this skin allergy.Hives. Urticaria, the medical term for hives, is an itchy rash that can indicate a significant underlying medical condition. You may notice raised pink/red bumps that appear to be of various sizes and shapes. The raised pink/red spots have pale centers on the skin. The hive spots may quickly change in location, size, and shape. While you may experience itching, it is usually not significant enough to lead to breaking skin.Hives are generally treated with an over-the-counter antihistamine. It won’t cure the hives, but it will relieve itching and potentially decrease the number of skin lesions. Hives are not contagious.Foods (e.g. peanuts, eggs, nuts, and shellfish), latex, medications (especially antibiotics such as penicillin and sulfa, aspirin, and ibuprofen), insect stings, and physical stimuli such as pressure, cold, heat, exercise, or sun exposure can all cause hives.Angioedema. Most commonly associated with hives, angioedema is a swelling that might involve lips, the eyes, and the hands and feet. Patients describe an abnormal stinging or tingling sensation, but it is generally not itchy or red.When to See Your DoctorAngioedema and hives are significant allergic skin conditions that can be part of a medical emergency. If you have angioedema of the face and neck there is a risk that you could develop significant breathing problems. These problems can be treated with systemic steroids to help decrease swelling and other symptoms. You should seek care immediately for any breathing problems or a significant worsening of symptoms.The most serious reaction to a trigger, anaphylaxis, is a medical emergency that must be treated with an injection of epinephrine. Article Is There Such a Thing as a Sun Allergy? Article Hives and Swelling Contact dermatitis and eczema are generally not medical emergencies. You can often try over-the-counter medications and treatments before seeking medical advice or prescription medication. If you treat with over-the-counter medication, you need to consider seeking medical care if redness, itching, or oozing of the lesion worsens or the rash is not improving after a week of over-the-counter treatment. A Word From VerywellSkin allergies can be very bothersome and cause irritating symptoms. Unfortunately, it can take a while to understand what factors are impacting your skin allergies as well as understanding all the different steps needed to get your condition under control. However, understanding basic principles will help you correctly identify the most likely culprit and determine the correct treatment plan.Sources: Beltrani VS, Bernstein IL, Cohen DE, Fonacier L. Contact Dermatitis: A Practice Parameter. Ann Allergy Asthma Immunol. 2006;97:S1–38.Joint Task Force on Practice Parameters. The diagnosis and management of urticaria: a practice parameter part I: acute urticaria/angioedema part II: chronic urticaria/angioedema. Ann Allergy. 2000; 85: S525–44.Leung DY, Nicklas RA, Bernstein IL et al. Atopic Dermatitis Practice Parameters. Ann Allergy Asthma Immunol. 2004;93:S1–21.