There are a number of conditions that give you dry, scaly skin, and eczema and psoriasis are two of the most common types.
While both conditions may have a few similarities, such as a genetic predisposition, the presence of itching, red and inflamed skin, and presence of skin lesions in any part of the body, they have several clear differences that could aid early identification of and appropriate treatment for either of them.
Understanding Eczema and Psoriasis
Eczema, or atopic dermatitis, is a hypersensitivity reaction in which the skin overreacts to certain triggers, such as soaps, fabrics, creams, cosmetic products, dyes, animal furs, and other irritants. Although it is a long-term condition; occurring as often as an individual is exposed to the triggers, many people with atopic dermatitis may outgrow the skin hypersensitivity after some years.
Psoriasis, on the other hand, is a chronic autoimmune condition, in which the immune cells stimulate the skin cells to multiply faster than they should. This causes the dead cells to build up into silvery-white scales on the surface of the skin. People who have psoriasis do not outgrow it and there is currently no cure for the disease.
Comparisons between Eczema and Psoriasis
Understanding the mechanism of disease of both conditions gives insight into the notable differences between both diseases.
Eczema makes your skin appear red and inflamed. It can also appear as dark leathery patches or small raised bumps, which could break open releasing fluid or pus.
Psoriasis, on the other hand, has a distinctive raised appearance, with well-defined thick red patches covered with silvery-white scales. The patches are well bordered from normal skin. Psoriasis skin patches are generally thicker and more inflamed than eczema. Psoriasis may also appear as salmon-colored plaques over the affected skin area.
Eczema typically appears on skin ‘bends’, including the inner areas of the elbow and knees, as well as the neck, wrists, and ankles. However, infants may have atopic dermatitis on their face, chest, arms, and legs.
Psoriasis typically occurs on the outside areas of skin ‘bends’ such as the back of the elbows and front of the knees. Although a type of psoriasis called inverse psoriasis may occur on the inner areas of the elbows, knees, and armpits, the characteristic appearance may give it away. Psoriasis may also appear on the palms, soles, genital area, scalp, and umbilicus.
While both conditions cause your skin to itch, the itch is usually mild in psoriasis and intense in eczema. Itching is typically worse at night with eczema and can be relieved with over-the-counter anti-itch medicines but not so much for psoriasis.
Age at Onset
Eczema has an earlier age of onset, beginning in infancy and early childhood. Often, a child outgrows eczema when he or she is much older. However, it is possible, but less common, for eczema to continue into adulthood. Usually, persistent atopic dermatitis in adulthood suggests the presence of other illnesses such as thyroid disease and endocrine disorders.
Psoriasis, on the other hand, has a much later age of onset; with peak onsets within two age brackets: 20 to 30 years and 50 to 60 years, and the median age at onset of 28 years. It rarely occurs in infants or toddlers, unlike eczema.
Eczema flare-ups are triggered by substances or materials that irritate your skin, such as soaps, fragrances, detergents, animal fur, fabrics such as wool and polyester, mold, pollen, dust, dandruff, and food substances. These substances are called allergens. Stress, hormonal changes, and infections can also trigger atopic dermatitis.
Psoriasis can be triggered by a few of these factors, such as stress and infection but not by the allergens mentioned above. Psoriasis is commonly triggered by factors that injure the skin, such as sunburn, scratches, cuts, and tattoos. These do not trigger eczema
It can also be triggered by vaccinations and medications including lithium, anti-malarial drugs, and some medicines for high blood pressure. Excessive alcohol intake and smoking also trigger psoriasis flare-ups and worsen the condition.
In contrast to eczema, psoriasis can be triggered by cold weather and relieved by hot weather in some people. In eczema, because sweating can trigger or worsen symptoms, hot weather will exacerbate symptoms
Prognosis and Outlook
Eczema usually resolves spontaneously as a child gets older and does not recur but Psoriasis is a lifelong disease with several episodes of exacerbations, which may be resistant to treatment.
Unlike eczema which has no negative effect on one’s quality of life, the complications of psoriasis, such as arthritis and ocular complications may significantly reduce one’s quality of life. It also affects one’s long-term survival by increasing one’s risk of heart disease, stroke, and kidney disease.
Since eczema and psoriasis have a hyperactive immune system underlying the mechanism of both diseases, the principles of treatment for both diseases are similar. However, because of the differences in specific mechanisms of both diseases develop, treatment may vary.
For Eczema, avoiding the potential triggers can help to treat the condition or reduce the frequency of flare-ups. These steps include:
- Avoiding harsh soaps and perfumes with strong fragrances.
- Avoiding hot baths
- Avoiding extremely hot temperatures
- Avoiding the specific substances, such as peanuts and eggs that one is allergic to.
- Placing dust-protective covers over carpets, mattresses, and pillows, and ensuring frequent cleaning and washing of dust-attracting household items.
Eczema can also be treated by applying an antihistamine cream on the affected skin area or simply taking an oral antihistamine, such as Benadryl. In moderate-to-severe cases, topical or oral corticosteroids may help relieve the symptoms.
Mild-to-moderate eczema and psoriasis can both be treated using topical corticosteroid creams or oral corticosteroids. These medicines lower inflammation and reduce the rate at which the skin cells grow. The discomfort and itch can also be relieved with moisturizing creams and emollients, just like eczema. Light therapy or phototherapy, which involves the use of controlled ultraviolet light to reduce the growth and multiplication of skin cells, is also useful for treating both eczema and psoriasis.
The difference in the treatment of psoriasis and eczema is in the components of the treatment. The 2013 consensus report of expert dermatologists across the globe notes certain recommendations for treating psoriasis. These include:
Methotrexate: This drug impairs DNA division, thereby inhibiting the division of cells. This reduces the rate at which skin cells divide. This drug is not indicated for the routine treatment of eczema.
Cyclosporine: Cyclosporine works by disrupting immune function. This medicine is used for one or several courses over a period of 3 to 6 months. This medicine is not indicated for the routine treatment of eczema. It is used in resistant cases of eczema.
Psoriasis treatment may also combine the above drugs with medicines called biologic agents, such as Adalimumab and Etanercept, which modulate the immune system to reduce its overactive effect on the skin. These medicines are only reserved for use in severe cases of eczema.
Other medicines which play a role in the treatment of psoriasis but less so in eczema include:
Anthralin; which reduces cell division in the skin; coal tar, which lowers inflammation and scaling in the skin, and; topical retinoid, which prevents the accumulation of dead cells on the skin surface by encouraging their replacement with new skin cells.
Psoriasis and eczema are diseases stemming from disturbances in the immune system. However, while both diseases may have some similarities, they have a lot of differences, knowledge of which helps patients and doctors easily identify either and institute the appropriate treatment.
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