Allergic skin conditions affect between 10 to 27 percent of children and 1 to 3 percent of adults, and lead to millions of doctor visits each year, according to the American Academy of Allergy Asthma and Immunology (AAAAI). The most common types of allergic skin conditions are hives, eczema and contact dermatitis. Hives are red, itchy swollen bumps that can appear anywhere on the skin. Hives are usually seen with angioedema, a swelling on the deeper layers of the skin. Eczematic rashes are dry, scaly and intensely itchy, and develop into fluid-filled lesions with continued irritation. Contact dermatitis is often seen as blistery, red rashes on the hands or other body parts that have had direct contact with an allergen.
Direct Contact
On direct contact, certain substances can cause skin-damaging contact dermatitis in people sensitive to them. Poison ivy, oak and sumac are the most common allergens causing contact dermatitis. Some people also react to perfumes, latex, cosmetics and nickel, such as those found in gold jewelry and metal alloys. Chromates found in cement, leather and paints may also cause contact dermatitis. Other people can develop eczema on contact with soap, while others develop hives when their bodies are injected with dyes from x-rays.
Food
About 27 percent of food-allergic children develop eczema and other skin allergies, reports the AAAAI. Milk, peanuts, nuts, eggs and seafood are the most common causes of food allergies in children, while fish, peanuts and shellfish are common among adults and older children. In some people, fresh fruits and vegetables cause oral allergy syndrome, characterized by itchy lips, tongue and throat and swollen lips.
Airborne Allergens
Airborne allergens such as cat dander, house dust, pollen or molds can cause eczema to worsen in some children. Children who suffer from asthma are especially vulnerable to eczema outbreaks on exposure to airborne allergens such as secondhand smoke and dust mites.
Infections and Viruses
In some people, acute bacterial or viral infections, such as the common cold, sore throat or bronchitis, can cause hives that last for a few weeks. In others, hives can break out when they get infected with hepatitis B, glandular fever and intestinal parasites.
Drugs
Drug treatments such as codeine, aspirin and non-steroidal anti-inflammatory drugs or NSAIDs can cause hives and swelling in some individuals. Allergic reaction to NSAID can be life-threatening if swelling occurs on the tongue and or throat and cause difficulty breathing. Antibiotics and high blood pressure drugs called ACE inhibitors can also cause allergic skin reactions.
