Chickenpox is contagious, characterized by itchy red spots, and is most common in childhood.
Many common rashes have similar features, so it can be hard to tell them apart without a picture, but there are ways to narrow them down. The first thing to consider is the location of the rash, as many tend to appear in specific areas. Other things to consider are how the area feels, such as if it is itchy, scaly, or numb, and what the rash looks like. It is also important to note the color of the rash or the color of any discharge, as it can differ between rashes.
A skin rash.
If possible, you should also try to determine what caused the rash. For example, it can occur right after eating certain foods or taking certain medications, or it can occur after swimming. The more specific information you have about a rash, the easier it will be to identify it. While consideration of these features can be helpful in identifying skin problems, you should see a doctor about any rash that appears quickly, lasts more than a few days, or is itchy or painful.
Location
Shingles causes a blistering skin rash.
Where the rash appears on your body is often one of the best clues as to what it is. Many rashes usually only occur on specific parts of the body, such as rosacea or athlete’s foot. Others occur in specific patterns, such as pityriasis rosea, which is sometimes called a “Christmas tree rash” because it tends to occur on people’s backs in the shape of a Christmas tree. Sometimes the location can also give a clue as to what caused it. For example, bacterial or fungal rashes tend to appear on warm, moist places on the body, such as the groin or armpit.
Eczema is a common skin rash.
Seeing that a rash has spread all over the body can also be helpful, as some are characterized by how quickly they spread or the patterns in which they spread. For example, eczema tends to occur on the insides of the elbows or the backs of the knees. You should also be aware of which parts of your body were not affected by the rash, as this could mean that something has prevented it from spreading there. People often see this with contact dermatitis, which often only occurs on exposed skin, or swimmer’s itch, which only occurs on the parts of the skin that are directly in the water rather than covered by a bathing suit or a cap.
How does the rash feel?
Hives can be very itchy.
Many common skin rashes are itchy, including ringworm, chickenpox, eczema, and impetigo. This could be due to an allergen, such as oil from a poison ivy plant, or a virus, such as chickenpox. It is important not to scratch, as this can often spread the rash over the body or to other people. When trying to tell the difference between itchy rashes, you should consider the location, as well as any other sensations you feel in the area, such as a burning sensation or dry skin. Rashes like eczema and psoriasis tend to cause dry, itchy skin, while hives or heat rash can be itchy and painful. Lack of sensitivity can also be an identifying sign; for example, herpes often burns or hurts, but can cause numbness, and a molluscum contagiosum rash is painless.
Appearance
Itchy and burning feet are often caused by athlete’s foot.
The texture of a rash can be very helpful in identifying it. Rashes can be flat, round, with raised edges, blisters or welts, or thick, hard patches. Mild rashes usually come with some swelling, but not blisters or hives; intertrigo is a good example of this. Many types have blisters, such as dermatitis, shingles, eczema, and chicken pox. Sometimes a rash may have bumps instead of blisters, which are raised but not filled with fluid. If the rash is caused by a fungus and has a specific shape, it will usually have raised borders, like ringworm.
A topical cream can be applied to relieve itchy skin.
The color of the area is also important. The rashes are usually red, pink, or purple, but some also have white scales or plugs. If the rash consists mainly of redness and swelling, it could be cellulitis, intertrigo, or athlete’s foot, depending on the location. If it’s just purple, it could be lichen planus. You should also note the color of any fluid or discharge; many have clear fluid-filled blisters, but impetigo blisters are filled with yellow fluid, molluscum contagiosum bumps can be filled with a white, sticky substance, and rosacea can have pus-filled pimples.
Table of common skin rashes
Affected area: Looks like: Looks like: Occurs in response to Dermatitis The area touched by the allergen. Itching, burning Redness, swelling, blisters. allergens Ringworm Body, feet, groin, scalp. Which produces itching. Raised red scaly rings. Mushroom. Varicella Whole body. Which produces itching. Blisters filled with clear fluid. Virus. Shingles Trunk or buttocks, but can be anywhere. Burning, tingling, painful, numb. Raised red dots and blisters. Virus. Urticaria All over the body. Itching, itching. Raised red welts. Allergens, extreme temperatures, infection. Impetigo Usually face, arms, legs. Which produces itching. Blisters with yellow liquid. staph bacteria. Swimmer’s itch Skin exposed to water. Itching, burning Red bumps or blisters. parasite. Rosacea face. Itching, burning Redness, swelling, thick skin, pus-filled pimples. Unknown. Eczema Knees, elbows, neck, etc. itchy, dry Oozing, bleeding blisters, and thick patches. Allergens, weather, disease. Psoriasis Scalp, elbows, knees, lower back. itchy, dry Thick red plates with white scales. Possibly hereditary. Miliaria Whole body. Itching, itching. Clear, fluid-filled bumps. heat Drug eruption Whole body. Which produces itching. Red spots that spread. Medicine. Intertrigo Warm, moist areas. Painful. red swelling. They can be bacteria, fungi or viruses. Lichen Planus Wrist or ankles, lower back, neck, legs. Which produces itching. Purple or red bumps with a flat top. Possibly allergens. Cellulite Legs, in general. Painful. red swelling. Bacterium. Molluscum contagiosum In children: face, trunk, armpits, extremities; in adults: groin. Without pain. Flesh-colored bumps with a white depression or plug in the center. Virus. Pityriasis rosea Chest, back, arms, legs. Sometimes it itches. Scaly pink spots with raised borders. Virus.
Athlete’s foot Feet. Itching, burning Redness, sometimes with blisters or sores. Mushroom.
Videos
Video 1 — Close-ups of chickenpox in a child.
Video 2: Information on how shingles develops.
Video 3 — Information on lichen planus.
Video 4 — Information on pityriasis rosea.
Video 5 — Information about psoriasis with images.
Additional Resources
www.mayoclinic.com – A slideshow of common skin rashes with pictures and descriptions.
www.webmd.com – Another slideshow of common rashes and skin conditions.
www.chiff.com: Images of common skin rashes and information on treatment options.
