Nickel allergy is a skin rash or irritation that occurs when you come into contact with nickel. This condition is a form of allergic contact dermatitis. Allergic contact dermatitis happens when your skin touches or comes near an ordinarily harmless substance. Nickel allergy is the most common type of contact dermatitis related to metal. The skin rash from nickel allergy may be …

Peanut allergies happen when your body mistakes peanut protein for something harmful. Your immune system responds by causing an allergic reaction, which could include hives, vomiting and swelling. Peanut allergies are the most common food-related cause of anaphylaxis, which can lead to swelling in your airways or a severe drop in blood pressure. Call 911 (or your local emergency service number) or get to an …

Albinism is a genetic disorder where you’re born with less melanin pigment than usual. Melanin is a chemical in your body that determines the color of your skin, hair and eyes. It’s also involved in optic nerve development, which means it helps your eyes function as they should. Most people with albinism have very pale skin, hair and eyes. The exact skin tone, hair …

A penicillin allergy occurs when your immune system reacts negatively to the antibiotic penicillin or an antibiotic in the penicillin family (beta-lactam antibiotics). Penicillin is a medicine that treats infections. When you take penicillin, the medicine destroys the outer wall of bacterial cells. This ultimately kills and removes a bacterial infection from your body. Just because you have a penicillin allergy today doesn’t …

Alcohol intolerance is an inherited metabolic disorder. Metabolic disorders affect your metabolism, the way your body converts and uses energy. An inherited metabolic disorder means you got this condition from your parents — they each passed down a mutated (changed) gene that resulted in this disorder. Even if your parents don’t have the condition, they can pass it to you. …

Pet allergies are certain proteins — called allergens — on your pet that cause your allergic immune system to overreact. These allergens are in animal fur, skin, urine (pee) and saliva (spit). It’s also in pet dander, which is tiny scales from your pets’ skin, hair or feathers. Usually, these proteins are harmless. However, your allergic immune system views them …

Alcohol poisoning happens when there’s so much alcohol in your bloodstream that it starts shutting down life-supporting areas of your brain. These areas control your breathing, heart rate and temperature. Alcohol poisoning is life-threatening. Alcohol poisoning typically happens when you consume a large amount of alcohol in a short amount of time. It often happens from drinking excess alcohol-containing beverages, like beer, …

A shellfish allergy is a type of food allergy. Shellfish are animals that live in the water and have a shell-like exterior. There are two types of shellfish: Crustaceans: shrimp, crayfish, crab, lobster. Mollusks: clams, scallops, oysters, mussels. What fish is shellfish? If you have a shellfish allergy, don’t eat these ingredients and foods: Abalone. Clams (such as cherrystone, littleneck, pismo, quahog). Cockle. …

Alcohol use disorder (sometimes called alcoholism) is a common medical condition. People with this condition can’t stop drinking, even if their alcohol use upends their lives and the lives of those around them. Alcohol use disorder can be mild, moderate or severe. Treatments may include medication and behavioral therapy. While people with this condition may start drinking again, studies show …

A wheat allergy is one of the most common types of food allergies. Your immune system overreacts to wheat you’ve ingested (eaten or drunk) or inhaled (breathed in). For many people, ingesting wheat is harmless. However, if you have a wheat allergy, your immune system views wheat as a harmful “invader,” like a bacterium or virus. A wheat allergy can be deadly. If …