An allergic skin reaction occurs when the immune system responds to an allergen, and causes immune cells to release histamine to the surface of the skin and bloodstream. Rashes involved with dry, itchy, swollen skin are common symptoms of an allergic skin condition. Speak with your physician to determine to causative agent and develop a treatment plan.
Allergic Contact Dermatitis
Allergic contact dermatitis is an inflammation of the skin caused by direct contact with an irritant or allergen. The causative agents for allergic contact dermatitis include nickel, poison ivy, cosmetics, and neomycin. This allergic reaction occurs within 24 to 48 hours of contact and may take up 14 to 28 days for the symptoms to resolve. Symptoms commonly associated with allergic contact dermatitis include itching, inflammation, and swelling of the area of skin exposed to the irritant. A skin rash that involves redness and blisters that ooze fluids and eventually crust making the skin appear scaly, thick and leathery is also observed. The Initial treatment for allergic contact dermatitis include washing the exposed area of skin with water and avoiding further contact with the irritant.
Hives
Hives is an allergic inflammation of the skin caused by the release of histamine in response to an irritant or allergen. Histamine dilates and increases the permeability of the blood vessels, allowing fluids to leak to the surface of the skin. This results in redness and swelling of the skin, and intensely itchy, raised, lesions that migrate around on the skin. The hives may range in size, and in some cases merge together. This blister-like rash occurs within 24 hours of exposure to the allergen, and resolves within days. The first line of the treatment is avoiding further exposure to the allergen, and applying moisturizing lotion to help with the dryness, and itch.
Eczema
Eczema is chronic skin disorder resulting in scaly, red, itchy rashes. Eczema is caused by a hypersensitivity reaction in the skin in response allergens such as soap, dander, or wool. Eczema can occur in any part of the skin, however, it often appears on the knees, elbows, and face. The rash typically involves blisters that are extremely itchy, and ooze fluids that eventually crust over. The skin is also red and inflamed, and becomes scaly and leathery as a result of the long-term itching, scratching, and irritation. Depending on the severity of the rash, your physician may prescribe a topical corticosteroid, and oral antihistamine to alleviate the inflammation, and itching.
Chronic Actinic Dermatitis
Chronic actinic dermatitis is a rare skin condition that mostly affects the elderly or middle-aged men. This condition often occurs in individuals with a history of dermatitis, and is caused by changes in skin cells as a result of exposure to sunlight or ultraviolet radiation. The immune system inappropriately recognizes proteins in the skin as foreign and dangerous, and releases antibodies that attack these cells. This improper immune reaction causes the skin by become red, inflamed, itchy and dry. Patches on thicken, hard, dry, itchy skin typically occurs on the face, head, arms, back, neck, and upper chest. This rash can develop within 30 minutes of exposure to sunlight, thus patients with this skin disorder should take strong measures to avoid exposure to sunlight.
References
- American Academy of Allergy, Asthma and Immunology: Allergic Skin Conditions
- American Academy of Allergy, Asthma and Immunology: Skin Allergy
- Medline Plus; Contact Dermatitis; November 2009
- UpToDate; Patient information: Hives (urticaria); Clifton O Bingham, III, MD; February 2010
- MayoClinic.com; Atopic Dermatitis (Eczema); April 2011
- DermNet NZ; Chronic Actinic Dermatitis; Vanessa Ngan; March 2001
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