- An Overview of the Different Types of Eczema
- Atopic dermatitis
- Contact dermatitis
- Dyshidrotic eczema
- Nummular eczema – nummular dermatitis
- Seborrheic dermatitis
- Stasis dermatitis
- Symptoms of Eczema
- Symptoms of Bed Bug Bites
- Diagnosis of Eczema
- Diagnosis of Bed Bug Bites
- Treatment of Eczema
- Treatment of Bed Bug Bites
- Prevention of Eczema
- Prevention of Bed Bug Bites
- Eczema Vs Bed Bug Bites: Key Points
- Related Questions
- Allergic Skin Disorders
- Overview – Discoid eczema
- Causes of discoid eczema
An Overview of the Different Types of Eczema
Eczema (eg-zuh-MUH) is the name for a group of conditions that cause the skin to become red, itchy and inflamed.
Eczema is very common. In fact, more than 30 million Americans have some form of eczema.
Eczema is not contagious. You can’t “catch it” from someone else. While the exact cause of eczema is unknown, researchers do know that people who develop eczema do so because of a combination of genes and environmental triggers. When an irritant or an allergen from outside or inside the body “switches on” the immune system, it produces inflammation. It is this inflammation that causes the symptoms common to most types of eczema.
There are several different types of eczema that you should know about:
- Atopic dermatitis
- Contact dermatitis
- Dyshidrotic eczema
- Nummular eczema
- Seborrheic dermatitis
- Stasis dermatitis
Though there are several distinct types of eczema, it is possible to have more than one type at a time.
All types of eczema cause itching and redness, but some may also cause your skin to blister, “weep,” or peel.
It’s important to understand which type you or your child may have and also your symptoms and triggers, so that you can best treat and manage your eczema. But the only way to be sure that you or your child has eczema and which type, is to make an appointment with your doctor.
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- Discover which triggers to avoid so your eczema doesn’t get worse
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Atopic dermatitis with scratch marks on the backs of the knees
Atopic dermatitis is a type eczema that is chronic and inflammatory. Though the exact cause of atopic is unknown, it happens when the immune system goes into overdrive in response to an allergen or irritant inside or outside the body. AD usually begins in childhood, often in the first six months of the life. When you or your child have AD, it might improve at times or it may get worse (when you may experience what’s called a “flare”).
Atopic dermatitis is part of what’s called the atopic triad, which includes two other allergic conditions (asthma and hay fever, which is also known as allergic rhinitis). Researchers believe that people who come from families with a history of atopic dermatitis, asthma and/or hay fever are more likely to develop atopic dermatitis themselves.
Some common symptoms of atopic dermatitis:
- Dry, scaly skin
- Redness (erythema)
- Cracks behind the ears
- A rash on the cheeks, arms and legs
- Open, crusted or “weepy” sores (usually during flare-ups)
Read more about AD symptoms, triggers and types of treatment.
Contact dermatitis on the wrist most likely caused by the metal watch dial
Contact dermatitis happens when the skin touches irritating substances or allergens. These make the skin inflamed, causing it to burn, itch and become red. There are several kinds of contact dermatitis but irritant contact dermatitis and allergic contact dermatitis are the most common. Contact dermatitis usually appears on the hands, or parts of the body that touched the irritant/allergen.
The most common irritants include:
- Industrial chemicals
- Tobacco smoke
- Acidic Foods
- Skin care products that content alcohol (but not cetyl alcohol)
- Some soaps and fragrances
- Allergens (usually animal dander or pollens)
Symptoms of contact dermatitis include:
- Redness and rash
- Burning or swelling
- Blisters that may weep or crust over
Read more about contact dermatitis symptoms, triggers and types of treatment.
Dyshidrotic eczema blisters appear on the edges of the soles of the feet
Dyshidrotic eczema (dis-HI-drotic eg-zuh-MUH) is a condition that produces small, itchy blisters on the edges of the fingers, toes, palms, and soles of the feet. Stress, allergies (such as hay fever), moist hands and feet, or exposure to nickel (in metal-plated jewelry), cobalt (found in metal-plated objects, and in pigments used in paints and enamels), or chromium salts (used in the manufacturing of cement, mortar, leather, paints, and anticorrosives) may be “triggers” of dyshidrotic eczema. This type of eczema is twice as common in women as it is in men.
Symptoms of dyshidrotic eczema include:
- Small fluid-filled blisters (vesicles) on the fingers, hands, and feet
- Scaly, cracked skin
Read more about dyshidrotic eczema symptoms, triggers and types of treatment.
Nummular eczema – nummular dermatitis
Nummular eczema looks different than other types of eczema with its round or coin-shaped lesions
Nummular (numb-mu-LUR) eczema, also known as discoid eczema and nummular dermatitis, is a common type of eczema that can occur at any age. It looks very different than the usual eczema and can be much more difficult to treat. People with nummular eczema develop coin-shaped spots on their skin, which may be very itchy. It is thought to be “triggered” by things like insect bites, reactions to skin inflammation, or dry skin in the winter.
Some symptoms of nummular eczema include:
- Round, coin-shaped spots
- Dry, scaly skin
- Wet, open sores
Read more about nummular eczema symptoms, triggers and types of treatment.
Considered a chronic form of eczema, seborrheic dermatitis (seb-uh-REE-ick dur-muh-TIE-tis) appears on the body where there are a lot of oil-producing (sebaceous) glands like the upper back, nose and scalp.
Seborrheic dermatitis on the scalp is called dandruff. Picture courtesy of DermNet New Zealand
The exact cause of seborrheic dermatitis is unknown, although genes and hormones play a role. Microorganisms such as yeast, that live on the skin naturally can also contribute to seborrheic dermatitis. Unlike many other forms of eczema, seborrheic dermatitis is not the result of an allergy.
People of any age can develop seborrheic dermatitis including infants (known as “cradle cap”). It is slightly more common in men than women.
People with certain diseases that affect the immune system, such as HIV or AIDS, and the nervous system, such as Parkinson’s disease, are believed to be at an increased risk of developing seborrheic dermatitis.
Seborrheic dermatitis often appears on the scalp, where symptoms may range from dry flakes (dandruff) to yellow, greasy scales with reddened skin. Patients can also develop seborrheic dermatitis on other oily areas of their body, such as the face, upper chest and back.
Common symptoms of seborrheic dermatitis include:
- Greasy, swollen skin
- White or yellowish crusty flakes
Read more about seborrheic dermatitis.
Stasis dermatitis happens when there is a problem with circulation to the legs
Stasis dermatitis is also called gravitational dermatitis, venous eczema and venous stasis dermatitis. It happens when there is a problem with blood flow in the veins and pressure develops (usually in the lower legs). This pressure can cause fluid to leak out of the veins and into the skin, resulting in stasis dermatitis.
Symptoms of stasis dermatitis include:
- Swelling around the ankles
And in more severe cases:
- Open areas (cracking or larger ulcers)
Read more about stasis dermatitis symptoms, triggers and types of treatment.
Trying to figure out the difference between eczema vs. bed bug bites? If your skin is covered in itchy red welts or splotches, your first thought might be that you are dealing with eczema. It is, after all, a very common skin condition. But you might find yourself looking at your bed and wondering, “Could it be bed bugs?”
Bed bug bites and eczema can appear and feel similar. But there are some telltale signs that can help you distinguish between the conditions, like the exact formation pattern for the red itchy spots, and whether you note signs of bed bugs in your home. In this article, we’ll help you differentiate eczema vs. bed bug bites with detailed information on symptoms, diagnosis, treatment and more.
Symptoms of Eczema
Let’s start by talking about eczema. This is a chronic skin condition that causes itchy, reddish, or brownish patches of skin.
The National Eczema Association lists the following types of eczema:
- Atopic dermatitis
- Contact dermatitis
- Dyshidrotic eczema
- Nummular eczema
- Seborrheic dermatitis
- Stasis dermatitis
Eczema on the arm of a person
Each of these types of dermatitis presents itself with different symptoms. Thankfully, many of them are quite specific.
- Stasis dermatitis specifically involves circulatory issues that are generally found around the ankles and the lower parts of the legs.
- Seborrheic dermatitis takes the form of flaky, oily skin. While it may occur anywhere, it is frequently on the scalp, where it is called “dandruff.”
- Nummular eczema causes round “coin” lesions. They usually have darker borders and lighter interiors, but this may or may not be pronounced or obvious.
- Dyshidrotic eczema produces blisters, which may form on the hands or feet.
- Contact dermatitis is a form of eczema which flares in response to contact with a substance to which the skin is hypersensitive, sometimes an allergen. It is characterized by a red rash that may itch or burn. Blisters can form that ooze.
- Finally, atopic dermatitis is the condition that people most commonly are referring to when they say “eczema.” It seems to be immune-related and is chronic in nature. It can go into remission for periods and flare for others. Symptoms include skin, which is itchy, red, dry, scaly, and sometimes breaks into weeping sores. It tends to look like a splotchy rash, but sometimes it can look like more scattered red spots which could be mistaken for bites. It can show up on the face, back, legs, hands, or other parts of the body.
So, when it comes to recognizing eczema vs. bed bug bites, some types of eczema are easier to differentiate from bed bug bites than others.
For example, if you spot those distinctive “coin” lesions, there is a good chance it could be nummular eczema.
If your hands are covered in raised blisters, dyshidrotic eczema is a possibility.
Have red spots which are somewhere other than your legs? You likely (though not definitively) can rule out stasis dermatitis.
Symptoms of Bed Bug Bites
Now let’s take a look at the symptoms of bed bug bites.
Bed bug bites:
- May be flat or raised
- Are small
- May cause redness, itching, and inflammation around them
- Can turn into blisters
- May take anywhere from seconds to days after infliction to become noticeable (sometimes weeks)
Bed Bug Bites on man’s legs
Hypothetically, a bed bug can bite you anywhere. But Orkin writes, “Bites are commonly found on the parts of the body that are more likely to be exposed to bed bugs during sleep – the hands, neck, face, shoulders, legs, and arms. While not always the case, bed bug bites are often grouped together in a small area and at times may occur in a line or a zigzag pattern.”
Interestingly enough, there can be variations in the exact appearance and symptoms of bed bug bites from one person to the next.
Orkin explains this as well, stating, “Since people will have various sensitivities to the bed bug’s bite, the size of the bite will vary, as well. Another factor that influences the size of a bed bug reaction is the number of times a person is bitten. Bite reactions of people bitten many times are also variable, and their response may be either more or less intense as the number of bites increases.”
Intriguingly, there are people totally unaffected by bed bugs. So, two people could sleep in one infested bed, and one person could break out into itchy bites, and the other might never even show a sign of having been bitten.
Rarely, an individual can react with life-threatening symptoms to bed bug bites, such as fever or labored breathing.
Because there are so many variations in the timing and symptoms of bed bug bites, differential diagnosis can be a challenge on your own.
Small, scattered spots in a zigzag pattern may very well be bed bug bites. But they could still feasibly be eczema.
A splotchy, large rash is more likely to be eczema than bed bug bites—but you still don’t know, since highly reactive skin could hypothetically form a large swath of inflammation around a cluster of bites. Scattered spots that are not in a zigzag pattern may be bed bug bites, or they could be eczema. And don’t forget that there are other skin conditions or bites which could be causing your symptoms as well. Bed bug bites and eczema are not the only possibilities.
Diagnosis of Eczema
Sometimes, you may be able to figure out if you have eczema on your own. It can start at any age, so you do not need to have had it since childhood to develop it later.
If you go to see a doctor, a simple clinical examination should be sufficient to establish a diagnosis. Occasionally, your provider may want to conduct a patch test.
Diagnosis of Bed Bug Bites
Mayo Clinic suggests that you look to your home and not just your body to try and figure out whether you have bed bug bites. Orkin also recommends taking a look at your sheets.
Here is some of what you can be on the lookout for:
- Are there any spots of blood on your bedsheets? That is a pretty good indication that you’re being eaten by bed bugs at night. Keep in mind that the stains may be more brownish than reddish in some cases. This is what happens when blood dries.
- Do you see any little brownish or blackish splotches along the seams of your mattress? This could be the waste that the bed bugs have excreted.
- Try taking a whiff of your mattress or sheets. Do they smell mustier than usual? Is there a faint sweetness to the odor? That could indicate the presence of bed bugs.
- See if you can spot any moltings from the bed bugs. These will be yellowish in color. They may be hard to spot as they could easily blend in with your mattress and sheets and will be quite minuscule.
Bed bugs are very tiny (the size of a poppy seed is about equivalent to the size of a bed bug), and they are geniuses at stowing themselves away, where nobody will ever find them. But sometimes you can spot them if you are cleverer than they are. Anywhere there is a narrow space like a crack in the headboard of your bed or even a nearby bedside table, that is where you might encounter hiding bed bugs. They wander further than you might reckon and could be up to 8 feet away from your bed (that’s according to Orkin).
Treatment of Eczema
Now that we’ve talked about diagnosing eczema vs. bed bug bites, let’s talk about approaches that you can take to treating both. We’ll begin with eczema.
The NHS writes, “Treatments for atopic eczema can help to ease the symptoms. There’s no cure, but many children find their symptoms naturally improve as they get older.”
So that is good news if you are looking this up on the behalf of your child. Here are some of the treatments that the NHS recommends for eczema sufferers:
- Emollients (also known as moisturizers).
- Topical corticosteroids.
- Antihistamines (in especially itchy, inflamed cases).
- Topical pimecrolimus or tacrolimus.
- Prescription medications prescribed by a dermatologist.
It also is recommended that you go out of your way to avoid scratching. Scratching will just make the inflammation worse. If bacteria get into open sores, this could result in a secondary infection.
Treatment of Bed Bug Bites
What if you have bed bug bites? In terms of actual treatment, you don’t have to do much of anything. Bed bug bites heal without intervention. It usually takes a couple of weeks, sometimes less.
If your bites are particularly itchy or painful, you might try taking an antihistamine. You also might use hydrocortisone cream.
Again, avoid scratching. This will make it less likely that you will develop a secondary infection that could require further treatment.
Prevention of Eczema
With both eczema and bed bug bites, prevention is key. Therefore, it’s important to figure out which of the two conditions you have.
To prevent eczema:
- Flares of eczema often happen in response to exposure to various triggers. You will need to take notes to identify what your triggers are. They could involve anything from heat exposure to certain detergents to milk or eggs. Once you know what your triggers are, avoid them.
- Do not just apply moisturizers as a treatment for an acute flare-up. Use them as a preventative measure as well.
- For specific forms of eczema, certain other preventative measures may be useful as well. For example, dandruff shampoo can be helpful with seborrheic dermatitis.
- While the simple steps above are adequate for most mild to moderate eczema cases, additional preventative treatments may be available to you if you have a severe case that resists more moderate management steps.
Prevention of Bed Bug Bites
If you have bed bugs rather than eczema (or in addition to eczema), you will simply continue to suffer from bites if you do not get to the root of the problem and get rid of the bed bugs.
In fact, you can even move to a new house and bring bed bugs with you. So, you must eradicate them.
The EPA provides recommendations here for killing the bed bugs once you locate them, including non-chemical methods such as heat or cold treatment or steam cleaners.
Once you believe you have eliminated the threat, use traps or interceptors to prevent future infestations of your furnishings.
Eczema Vs Bed Bug Bites: Key Points
We have now explored the similarities and differences between eczema vs. bed bug bites. Let’s quickly review the key points:
- Presents itself in several different ways depending on the specific type present. It will probably be itchy and may show up as reddish or brownish patches or spots that can look quite similar to or quite different from bed bug bites.
- It’s a chronic condition that may flare-up at different times.
- It does not have a cure.
- It can be managed using conservative treatment and prevention protocols in most cases including moisturizers, avoiding triggers, and using medications.
Bed bug bites:
- Appear as small, itchy red spots that may or may not be raised. These sometimes blister. It can take seconds or weeks for them to appear after you are bitten. They may or may not have a zigzag pattern.
- Signs of bed bugs such as blood or excrement on sheets or on your mattress may be present.
- While bed bug bites resolve on their own, they will continue to appear until you remove the infestation.
Hopefully, you can figure out whether you have eczema, bed bugs, or both on your own, and come up with a plan to get your symptoms under control. But, remember, it can always be helpful to consult with a medical professional, especially if you are worried that you might have something else going on.
1. How can you tell the difference between bed bug bites and flea bites?
Flea bites and bed bug bites look very similar. Flea bites are less likely to swell than bed bug bites. They also are more likely to be clustered together and located near the ankles. The zigzag pattern which is common with bed bug bites is not associated with flea bites (but could form through coincidence).
2. What scent keeps bed bugs away?
If you are looking for a simple, yet natural way to ward off bed bugs, they reportedly do not like the smells of lavender, cinnamon, tea tree oil, citrus or rubbing alcohol.
Allergic Skin Disorders
Eczema is a group of itchy, inflammatory skin conditions. Another name for eczema is atopic dermatitis. Eczema may start in infancy or childhood and persist into adulthood. For others, eczema lessens with age. Eczema starts as a cluster of blisters that progresses into a thick, scaly, intensely itchy rash. There are many different types of eczema.
- Atopic dermatitis is a form of eczema related to the same immune reaction that underlies allergy and asthma (atopic disease). The condition tends to be chronic.
- Contact dermatitis results when allergens or irritants provoke skin inflammation. Allergens may include plants, pets, and certain foods. Irritants may include chemicals in cleaning products, beauty products, paints, and solvents. Contact with fragrances or certain fabrics may provoke dermatitis.
- Dyshidrotic dermatitis results in small, fluid-filled blisters that form on the hands and feet. The blisters are intensely itchy.
- Neurodermatitis (lichen simplex chronicus) is an intensely itchy rash that often occurs on the forearms, thighs, or ankles. The intense discomfort of the rash provokes scratching — which increases itching — prompting more scratching.
- Nummular dermatitis is a coin-shaped scaly patch or sore that may occur after an injury such an insect bite, abrasion, or burn.
- Seborrheic dermatitis (seborrheic eczema) causes yellow, flaky patches, usually on the scalp.
- Stasis dermatitis is a rash that occurs on the lower legs when there is a problem circulation of blood and return of blood to the heart.
Eczema is a term for several different types of skin swelling. Eczema is also called dermatitis. Most types cause dry, itchy skin and rashes on the face, inside the elbows and behind the knees, and on the hands and feet. Scratching the skin can cause it to turn red, and to swell and itch even more.
Eczema is not contagious. The cause of eczema is unknown. It is likely caused by both genetic and environmental factors. Eczema may get better or worse over time, but it is often a long-lasting disease. People who have it may also develop hay fever and asthma.
The most common type of eczema is atopic dermatitis. It is most common in babies and children, but adults can have it too. As children who have atopic dermatitis grow older, this problem may get better or go away. But sometimes the skin may stay dry and get irritated easily.
Treatments may include medicines, skin creams, light therapy, and good skin care. You can prevent some types of eczema by avoiding
- Things that irritate your skin, such as certain soaps, fabrics, and lotions
- Things you are allergic to, such as food, pollen, and animals
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
The blisters usually last around three weeks and, once they dry out, your skin might be scaly in the aftermath, the Mayo Clinic says. Relentless, the blisters usually come back for another go, sometimes before your skin even has a chance to heal completely from the previous round.
You have a higher risk of developing dyshidrotic eczema if you also have atopic dermatitis, contact dermatitis, dyshidrotic eczema in your family, or hay fever, the AAD says. People who have sweaty or moist hands may also have flares every spring and summer when the temperature rises and they’re more prone to perspiring. Finally, the condition is more common in people whose hands are wet a lot throughout the day like health care workers, hairstylists, and florists, as well as people who work with cement, chromium, cobalt, or nickel, the AAD says.
There are a few ways to treat this condition, per the Mayo Clinic, including corticosteroid creams and ointments to speed up the blisters’ progress. The only way to figure out what exactly is best for you is to discuss your case with a doctor so you can get back to using your hands and walking around in peace.
3. Nummular dermatitis
Sometimes called discoid eczema, this describes coin-shaped or oval sores that may pop up on your skin after an injury like a burn, abrasion, or insect bite (because apparently those just aren’t enough?). Nummular dermatitis usually starts on your legs, torso, arms, hands, and feet as tiny, red spots and blister-like sores that weep fluid and crust over, the AAD says. Then different spots actually join together and grow into a distinct coin-shaped patch. The patches can last for weeks or even months, itching and burning as they stick around.
Experts aren’t 100 percent sure why people get nummular dermatitis, but risk factors include having injured your skin in some way, having very dry skin, living in a cold, dry area, or having some other form of eczema like atopic dermatitis. Your risk may also rise if you take medications like isotretinoin (which is used to treat severe acne) and interferon (which is used to treat several cancers and some viral infections), the AAD says. Having a sensitivity to substances like nickel may also play a role.
Doctors generally treat nummular dermatitis with drugs to reduce inflammation and itchiness, the AAD says. But, if your oozing blisters create a portal for a bacterial skin infection, you may also need an antibiotic. Your doctor will also recommend that you hydrate your skin really well, the AAD says, and they can offer specific tips to help you do just that.
4. Seborrheic dermatitis
Seborrheic dermatitis, sometimes known as seborrheic eczema, mainly impacts people’s scalps. It usually causes scaly patches, red skin, and, yup, dandruff that just won’t quit. It can also impact other oily areas of your body like your face, the sides of your nose, and your eyebrows, ears, eyelids, and chest, the Mayo Clinic says.
Experts aren’t 100 percent sure what causes seborrheic dermatitis, but they think it may have something to do with a yeast called malassezia that’s normally in your skin’s oil secretions, according to the Mayo Clinic. An overactive immune system may also be a factor.
Treatment generally includes things like drugs to control inflammation and antifungal shampoos to combat yeast overgrowth, the Mayo Clinic says. You may even be able to use these shampoos on parts of your body besides your scalp that are affected, or use mild shampoo to wash areas like your eyelids. As with many other conditions, warding off seborrheic dermatitis involves babying your skin while using the right combination of products to make your skin behave as well as possible. Your doctor can help you land on the right mix of methods for you.
5. Stasis dermatitis
Also called venous eczema, this condition is distinct from others on this list in that it’s linked with poor circulation. Since poor blood flow usually happens in your lower legs, this is where stasis dermatitis most often crops up, the AAD says. Insufficient circulation can make fluid build up in your legs, creating pressure and making it hard for oxygen and blood to reach your skin, which is when symptoms arise.
Causes of discoid eczema
The cause of discoid eczema is unknown, although it may happen as a result of having particularly dry skin.
When your skin is very dry it cannot provide an effective barrier against substances that come into contact with it. This could allow a previously harmless substance, such as soap, to irritate your skin.
It’s important to look carefully at all the chemicals in cosmetics and toiletries that may have come into contact with your skin. Contact dermatitis, a type of eczema caused by coming into contact with a particular irritant, may have a role in discoid eczema.
Some people with discoid eczema also have a history of atopic eczema, which often happens in people who are prone to asthma and hay fever. However, unlike atopic eczema, discoid eczema does not seem to run in families.
Other possible triggers
An outbreak of discoid eczema may sometimes be triggered by a minor skin injury, such as an insect bite or a burn.
Some medicines may also be associated with discoid eczema, as patches of eczema can appear in people taking:
- interferon and ribavirin – when they’re used together to treat hepatitis C
- tumour necrosis factor-alpha (TNF-alpha) blockers – used to treat some types of arthritis
- statins (cholesterol-lowering medicine) – which can cause dry skin and rashes
Dry environments and cold climates can make discoid eczema worse, and sunny or damp (humid) environments may make your symptoms better.