Dry and scaly skin woes can be due to a number of skin conditions. Two that can sometimes appear so similar that it's tough for doctors to tell the difference are psoriasis and eczema.
Psoriasis is a condition that occurs when a person's immune system triggers skin cells to grow faster than they usually should. Instead of the dead skin cells coming off the skin, they build up on the skin.
Eczema can be caused by a number of factors. These include environmental factors, bacteria exposure, allergens, and family history.
Both conditions can cause red, itchy skin but have different causes and different treatments. As a result, it's important to understand the differences.
Eczema tends to appear in the "bends" of the skin, such as the crooks of elbows and backs of the knee. Psoriasis can also appear on the elbows and knees.
However, both may also appear on the face, buttocks, or scalp, most commonly in children.
Itching can be one of the significant differences between eczema and psoriasis. Psoriasis tends to cause mild itching while eczema causes intense itching.
If a person does scratch the skin, the results can be swollen, sensitive, and even raw skin. Eczema itching is usually worse at night.
Age of occurrence
Children tend to experience eczema at greater rates than adults. According to the Nemours Foundation, eczema tends to subside at about age 5 or 6.
However, some young people may have flare-ups during puberty.
According to the National Psoriasis Foundation, psoriasis typically develops between the ages of 15 and 35. Babies rarely have psoriasis.
Psoriasis can sometimes cause joint stiffness as well as swelling. In addition, psoriasis can also affect the nails. Eczema does not typically involve these areas, particularly in regards to joint swelling.
Certain factors are known to trigger psoriasis episodes or worsen existing psoriasis. Examples include:
- Cold weather
- Excess alcohol consumption
- Taking certain medications, such as lithium and high blood pressure medicines
Keeping the skin clean and moisturized while avoiding harsh soaps and very hot water can relieve psoriasis discomfort and reduce any itching.
Mild-to-moderate psoriasis treatments can include applying corticosteroids. These medications are available over the counter. They work by reducing inflammation and itching. In addition, they stop skin cells from growing too quickly.
Applying moisturizing creams is also helpful because it can lessen itching, dryness, and scratching. While it won't necessarily heal psoriasis, it can reduce the symptoms.
Moderate-to-severe psoriasis can be treated with stronger medications available by prescription. These include:
- Anthralin: This medication promotes normal DNA activity in the skin, which can reduce the incidence of psoriasis. However, the cream can be highly irritating and staining to areas of skin unaffected by psoriasis.
- Coal tar: This product can help to reduce inflammation and scaling. The topical product is available both over the counter and by prescription.
- Salicylic acid: This ingredient is included in medicated shampoos and topical solutions. When applied to the skin, it can reduce psoriasis' scaly appearance and encourages new skin cells to replace old ones.
- Synthetic Vitamin D creams and solutions: Prescription Vitamin D creams include calcipotriene or calcitriol.
- Topical retinoids: Retinoids are a form of vitamin A that encourage new skin cells to replace old ones. However, topical forms can be irritating to the skin and make it especially sensitive to the sun.
Like eczema, psoriasis can be treated with light therapy, which is also known as phototherapy. This treatment involves controlled exposure to ultraviolet light, which slows down skin cell turnover and reduces inflammation.
If topical treatments don't work to reduce the incidence of psoriasis, medications are available by injection. These include retinoids, methotrexate, cyclosporine, and immune-modulating drugs such as etanercept.
No cure exists for eczema, and the condition can be long-lasting. Eczema tends to affect children in greater numbers. Children may "grow out of it" and not experience the condition as they age.
A person may also go for quite some time without symptoms, then experience a flare-up. Flare-ups can be triggered by many different factors.
Steps a person can take to treat eczema include:
- Avoiding harsh soaps and highly fragranced products
- Refraining from taking very long, hot baths or showers
- Avoiding tobacco smoke
- Applying topical corticosteroid creams to itchy areas
- Applying an antihistamine cream or taking an antihistamine, such as diphenhydramine
- Applying cool, wet compresses to the skin to avoid scratching
- Using light therapy in a controlled manner to avoid the side effects of excess sun exposure, such as skin cancer
- Taking steps to reduce stress by practicing relaxation techniques such as meditation, yoga, or Tai chi
- Avoiding extremely hot temperatures as sweat can worsen symptoms
Keeping the skin clean, moisturized, and dry can help to reduce eczema symptoms.
Because allergies can trigger eczema, avoiding substances a person knows they're allergic to can help. Examples of these substances include foods such as eggs, milk, peanuts, soybeans, fish, and wheat.
Exposure to dust from furnishings can also contribute to eczema. Placing dust-protective covers over pillows and mattresses and frequent cleanings of dust-attracting items may also help.
If a person's eczema is severe and doesn't respond to at-home treatments, a doctor can prescribe creams to reduce eczema occurrence and symptoms. These medicines are known as calcineurin inhibitors. Examples include tacrolimus and pimecrolimus. These two drugs should be used with caution as they carry a warning about a
Excessive itching may result in open wounds that can become infected. When this is the case, a person may need to apply a prescription topical antibiotic cream or take an antibiotic. Caregivers can also give their child soft gloves to wear in bed to keep them from scratching while sleeping.
While it's rare that a person will have both eczema and psoriasis, it is possible.
A study published in the journal Science Translational Medicine studied patients who had both eczema and psoriasis. The researchers found that people have different genes present in the skin tissue of each condition type that could help doctors more definitively diagnose each condition.
While there are differences between the conditions, they can present as similar to the other. This makes it difficult for doctors to diagnose the condition and recommend or prescribe the appropriate treatments.
As some treatments can be very expensive, it's important that the most targeted treatment is prescribed. If a person has both skin conditions, they may have to apply different treatments to each.
Skin conditions that cause similar symptoms
Eczema and psoriasis are not the only skin conditions that can resemble the other. Examples of other skin conditions that cause similar symptoms include:
- Athlete's foot
- Contact dermatitis
- Seborrheic dermatitis, also known as "cradle cap"
- Shingles, a viral infection caused by the same virus that results in chickenpox
- Urticaria, also known as hives
When a person has a skin condition of an unknown cause, they should see their physician to try and find out more about the condition's potential cause.