5 Common Causes of Skin Irritations on the Face

Feeling hot, hot, hot? Heat rash, also known as prickly heat or miliaria, most commonly affects babies, especially when they're overdressed on a sweltering day. (Unlike grown-ups and older kids, infants can't exactly peel off a layer or voice their discomfort -- at least not in any articulate fashion.) With heat rash, the sweat ducts become blocked and swollen, and sweat accumulates under the skin, causing tiny dots, pimples or blisters to appear on the face, head, neck, shoulders and under the armpits [source: Mayo Clinic]. This is why infants, whose sweat ducts aren't fully developed, are at risk.

But adults can develop heat rash too, especially if they live in a tropical climate, perspire abundantly and don't wear breathable clothing [source: Mayo Clinic]. Hospital patients and others confined to their beds for long periods of time can sometimes get heat rash on their backs [source: DermNet NZ]. Greasy or oily face creams and lotions can also trigger flare-ups by blocking the sweat glands [source: Braff].

Whether you're a babe in arms or a hiker in Death Valley, heat rash is easily treatable. If possible, step into an air-conditioned room, slip into something lighter and cool off in front of a fan [source: Mayo Clinic]. Cold water compresses and calamine lotion can often soothe the prickly feeling that accompanies heat rash [source: DermNet NZ].

If the spots and blisters don't disappear after a few days, give your dermatologist a call. He or she may prescribe a topical steroid or even an oral antibiotic [source: Braff].

Ever enjoyed a juicy mango, a ripe tomato or a crisp apple, only to notice redness and swelling around your mouth and face? You're probably experiencing a mild reaction to proteins in some fruits and vegetables (as well as some tree nuts), known as oral allergy syndrome. Chances are you suffer from seasonal allergies too, since these proteins are known to resemble pollen [source: Children's Hospital of Pennsylvania].

For more severe reactions, pop an antihistamine and avoid the food in the future. But if you're not yet ready to give it up entirely, try cooking it, which alters the offending proteins, or removing its peel, which contains the highest concentration of allergens [source: Landau].

In some cases, food reactions that cause rashes on your face and body indicate a severe allergy, particularly if you experience other symptoms such as nausea, vomiting, diarrhea, lightheadedness, nasal congestion, shortness of breath and difficulty swallowing. Among older children and adults, the most common culprits include fish, peanuts, shellfish and tree nuts [source: HealthCentral].

If you think you might have a food allergy, get to a doctor for comprehensive allergy testing. Although it's rare, severe reactions can be fatal, so you'll need to avoid the trigger and possibly carry an epinephrine injection in case of accidental ingestion [source: WebMD].

How's this for irritating? You're finally prescribed the right remedy for a nagging or acute health problem, but instead of relief you wind up with hives, blisters or bright red patches on your face or body. When rashes occur with a new drug, it's known as a drug eruption -- and it may mean you're allergic to the medication [source: Patient.co.uk]. Though any medication can cause an unwanted reaction, these tend to be common triggers: Penicillin, sulfa medicines, barbiturates, insulin, anticonvulsants and drugs for hyperthyroidism [source: WebMD].

Report any mild drug reactions to your doctor, who may want to rule out other conditions before abandoning the medication altogether. In the short term, over-the-counter antihistamines can help with swelling and itching [source: Patient.co.uk].

If you ever experience trouble breathing and develop a rash, call 911 or go to an emergency room right away [source: WebMD]. And a blistering rash that covers the entire body, including the mucous membranes (aka your mouth, nose, eyes, etc.), can indicate a life-threatening drug reaction, so seek immediate help if one appears [source: WebMD].

Lazy rambles through the great outdoors can be fun, inspiring and relaxing. But redness, itching, swelling and blisters from contact with poisonous plants? Not so much -- especially when it affects your face.

We've all heard of poison ivy, poison oak and poison sumac, but that doesn't mean we know them when we see them. Common causes of contact dermatitis, these plants release an oily resin known as urushiol, which produces an allergic reaction in many (but not all) people. You can get a rash from directly touching a plant like poison ivy, but you can also get one from clothes, shoes, gear, tools and pets contaminated with urushiol [source: Children's Hospital of Pennsylvania].

Rashes from poisonous plants typically resolve on their own, but you'll be itching like crazy in the meantime. Try an over-the-counter corticosteroid, calamine lotion, oatmeal baths or an oral antihistamine to stop the insanity. For very severe rashes that linger for weeks, doctors may prescribe an oral corticosteroid, such as prednisone, or an antibiotic [source: Mayo Clinic].

Contrary to popular belief, scratching doesn't spread rashes caused by poison ivy, poison oak and poison sumac. Nevertheless, resist the urge so you don't develop scars or a bacterial infection -- two things you definitely don't want on your face.

Looking to point blame for the unsightly rash overtaking your face? Check in your makeup bag or next to the bathroom sink. Cosmetics -- from foundations and bronzers to cleansers, lotions and masks -- can cause problems for your skin, causing dryness, allergic reactions and various forms of dermatitis. Some surveys show that up to 25 percent of people have had an unwanted skin reaction to a cosmetic.

It's hard to predict what might irritate your skin, and even your favorite products can suddenly turn on you after decades of use [source: WebMD]. But if you know your skin tends to be on the sensitive side, there are certain ingredients you should avoid. When choosing a cleanser, for instance, beware of sodium lauryl sulfate, a tough emulsifier, and drying antibacterial agents like triclosan. Dishpan hands are bad enough, but nobody wants chapped skin on the face [source: Percia].

While shopping for moisturizers and anti-wrinkle creams, watch out for artificial dyes, fragrances and parabens, which can set off allergic reactions. Keep exfoliating ingredients such as alpha hydroxy acids and retinoids to a minimum, lest you invite irritation by sloughing off too much skin [source: Girdwain]. In the makeup aisle, steer clear of known irritants such as ultramarine blue, mica, bismuth oxychloride and talc [source: Percia].

If you think a cosmetic may have irritated your face, wash it off immediately with a gentle cleanser. Then test it on a small patch of skin on the inside of your elbow, checking for redness, swelling, itching or burning over the next 48 hours [source: WebMD].