Rashes, bites and other skin ailments

From acne to poison ivy to bug bites, learn how to recognize symptoms and provide treatment to conditions that attack your skin.
© MSN Healthy Living // © MSN Health

The skin is the largest organ in the human body, and some people go to great lengths to protect it. Flawless skin is envied. And yet, it's constantly susceptible to all kinds of diseases, infections and irritations – from the sun, bugs, plants, illnesses or just the wear and tear of old age.

So what are some of those common skin ailments? And what should you do about them? Click through to Bing to find out.

--By Michael Ko for MSN Healthy Living

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Poison Ivy

People who touch poison ivy could develop a painful, itchy skin rash, characterized by bumps, blisters, lines or streaks. The rash is caused by an allergic reaction to an oily resin called urushiol, which is found in every part of the plant, including the leaves, stems and roots. Urushiol can stick to almost anything, including gardening tools, clothes, sports equipment or pets, which means you can get the rash from indirect contact, reportedly even years later.  

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Tick bites

Small, spiderlike animals that live in the fur and feathers of birds and animals, ticks can bite, causing flu-like symptoms, allergic reactions and rashes or sores. Ticks carry Lyme disease, a bacterial infection that can cause a rash that may look like a target or a bulls-eye. Tick bites can also cause Rocky Mountain spotted fever, which features a rash made up of tiny, flat purple or red spots that start on the palms of the hands and soles of the feet, then spreads.

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Mosquito bites

When the mosquito's mouth pierces the skin – only the female mosquito bites – it injects its saliva as it siphons blood. The saliva triggers the characteristic itching, redness and bumpiness on human skin. Sometimes, children can get "skeeter syndrome," a severe reaction with blisters, bruises and hives. Infected mosquitos can also transmit diseases to people and livestock, like the West Nile virus, yellow fever, malaria and some types of brain infections. Some authorities argue that mosquitos are the most dangerous animals on the planet.

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Spider bites

While almost all spiders are venomous – that's how they hunt – only a few have fangs and venom powerful enough to hurt humans. Two in the U.S. include the black widow and the brown recluse. Black widow bites first cause slight swelling and red marks, then pain, stiffness and possibly a fever, nausea and abdominal pain. The brown recluse's bite produces mild stinging, followed by a blister that sloughs off to leave a deep, enlarging ulcer. Experts say most presumed spider bites are bites from other bugs.

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Bedbug bites

Bedbugs are flat, parasitic insects that feed on the blood of people and animals while they sleep. Reddish-brown in color and wingless, they range from 1-7 millimeters across, the largest being roughly the size of Lincoln's head on a penny. Although traditionally seen as a problem in developing countries, bedbugs are spreading rapidly throughout the U.S., Canada and Europe, and have made news after being discovered in five-star hotels. Bedbug bites are similar to flea and mosquito bites but sometimes appear in a straight-line pattern (see them).

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Eczema comes from a Greek word meaning to "boil over," an apt description for the red, inflamed patches that occur with this disease, believed to be related to a malfunction in the body's immune system. One of the most severe forms is called atopic dermatitis (AD), which typically affects the insides of elbows, backs of knees and the face. AD often begins in childhood, during infancy, with scaly skin, cracks behind the ears, and rashes on the cheeks, arms and legs. During flare-ups, open "weeping" sores may develop from scratching.

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Psoriasis is a skin disorder that occurs when the immune system mistakenly sends out signals that speed up the growth cycle of skin cells. Normally skin cells take about 3-4 weeks to replace themselves. In patients with psoriasis, they may take 2-6 days, resulting in dry, scaly, crusty skin. Plaque psoriasis is the most common, appearing as red, inflamed lesions covered by a silvery white buildup of dead skin cells. Psoriasis is associated with other health conditions like diabetes, heart disease, arthritis and depression.

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Acne is a skin condition that appears on your face, neck and upper body. It occurs when your pores become clogged with oil and dead skin cells. The hair follicles are connected to glands, which produce an oil called sebum meant to naturally lubricate your hair and skin. But excess amounts can be problematic and harbor bacteria and infection, leading to whiteheads, blackheads, pimples or cysts. Hormonal changes in adolescence, especially, can over-stimulate the oil-producing glands.

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Cold sores

Sometimes called fever blisters, cold sores are groups of small blisters that erupt around the lips, gums or roof of the mouth. The skin is often red and swollen, and the blisters may break open, leak clear fluid and then scab over after a few days. Cold sores are contagious and caused by the herpes simplex virus, which can also cause genital herpes. Although many people use the terms interchangeably, cold sores are different than canker sores, which are bacterial infections that cause ulcers in the mouth.

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