Psoriasis and neurodermatitis are identical in some symptoms and very different in others. Dermatologist Dr. med. ChristineSchrammek-Drusio explains similarities and differences and explains which care helps and why.
Autoimmune diseases arise when the immune system regards the body's own tissue as foreign, attacks it and initiates defense reactions (e.g. inflammation). Complex disease patterns are set in motion by autoantibodies or certain white blood cells (lymphocytes). Symptoms often show up on the skin. There is currently the thesis that autoimmune diseases are caused by innate predisposition in combination with external influences. Despite intensive research, the exact cause has not yet been fully clarified.
Psoriasis is a real autoimmune disease, the basis of which is an excessive defense (inflammation with reddened skin) and repair program (increased formation of horny layer) of the skin.
Neurodermatitis is not a classic autoimmune disease. The most important causes are the impaired barrier function of the skin with moisture loss and the genetically determined tendency of the immune system to react excessively to stimuli from the environment such as pollen, food, animal hair.
Both diseases are inflammatory skin diseases that are genetically determined, ie inheritable. Furthermore, both skin diseases are associated with itching and typically run in episodes, ie (relatively) symptom-free times alternate with phases of pronounced skin changes. There is nothing more in common. However, there are clear differences.
The two diseases can be clearly distinguished on the basis of their symmetrical distribution pattern on the body. While atopic dermatitis tends to affect the flexor sides, ie mainly the elbows and hollows of the knees, but also the face and neck, skin changes in psoriasis are more likely to be found on the extensor sides, i.e. the elbows and knees. Psoriasis can also affect the whole body and scalp, while the face is usually unaffected. Sometimes there can be characteristic changes in the nails.
The respective skin changes are also characteristic: In atopic dermatitis, the affected skin is reddened to varying degrees. It can be oozing, blistering, or dry or leathery.
In contrast, psoriasis usually presents with coarse, silvery flaking on reddened skin. The so-called plaques are sharply demarcated.
Neurodermatitis, also called atopic dermatitis, appears for the first time to 80% within the first two years of life and belongs to the group of atopy, which also includes hay fever and allergic asthma. Neurodermatitis sufferers are often prone to allergies. Trigger factors (key stimuli, triggers) of atopic dermatitis are stress, long exposure to water, dry air, sweat (often worsening in the summer months) and contact with allergens.
70% of psoriasis occurs from the 3rd decade, but 30% can also occur after the 40th year of life. The trigger factors here include external mechanical stimuli of the skin, certain medications (e.g. antihypertensive agents and pain relievers), nicotine, alcohol, obesity, stress and bacterial and viral infections. Sunlight and warmth have a positive influence, so the disease is usually better in the summer months. In addition, today psoriasis is no longer viewed as a disease strictly limited to the skin, but rather as a systemic disease. Patients can also suffer from psoriatic arthritis, inflammation in particular of the small joints (fingers) but also of the large joints (knees, hips).
Even if knowledge about the diseases has expanded considerably in recent years, the precise mechanisms have not yet been fully researched. The causes are very complex and a cure is not (yet) possible. Thanks to various medical therapies, however, the relapses of the disease can be reduced and alleviated.
Cortisone creams and Kortiso-nersatz-preparations - In the acute stage of eczema with severe inflammation (eczema) on the skin cortisone creams help for 3-5 days followed by slow reduction of application frequency. Afterwards, cortisone replacement preparations (calcineurin inhibitors) can keep the skin in good condition. Calcineurin inhibitors, similar to cortisone creams, have an anti-inflammatory effect on the skin by regulating the activity of certain immune cells. These creams and ointments are also approved for long-term use. On the other hand, cortisone should only be used for a short time in order to avoid the skin getting used to it and the occurrence of side effects.
Antihistamines - In severe cases, topical cream and ointment treatments are no longer enough. Then medication is required from within. Cortisone and anti-allergy tablets (antihistamines) are used here. Furthermore, one should, as much as possible, avoid substances that have been detected in the allergy test. In some cases this is very difficult, for example with pollen exposure. However, it is possible to avoid allergies to certain animal hair (dog or cat hair).
Creams with vitamin D derivatives - In addition to locally applied cortisone creams, the treatment of psoriasis also includes creams with vitamin D derivatives. These creams contain derivatives of the body's own hormone vitamin D3 and, among other things, inhibit the division of the basal cells of the epidermis on the skin. This is much more active in psoriasis sufferers. Usually the epidermis renews itself within 26–28 days. During this time, new cells are formed and the aged, keratinized keratinocytes are almost invisibly rejected. In psoriasis, the keratinization of the affected areas takes place much more quickly within 3–7 days, which then appears as the typical silver-white flaking.
Light therapy - There is also the option of light therapy (UV-A radiation). This also has an inhibitory effect on the rate of cell division in the epidermis.
Weight loss, alcohol and nicotine abstinence - Furthermore, patients often benefit from weight loss and alcohol and nicotine abstinence.
Medication from within - In severe cases, medication from within may also be necessary. Various tablet therapies are permitted (fumaric acid ester, methotrexate, apremilast, ciclosporin), all of which model the immune system in different ways, reduce inflammatory processes on the skin or influence the rate of cell division in the epidermis.
Syringes - In the meantime there are also modern syringe therapies using biologics (genetically engineered drugs) that suppress certain inflammatory mediators on the skin in an even more targeted and thus even more selective manner.
In addition to the medical therapy options, appropriate cosmetic accompanying measures for the skin are also of great importance. With the cosmetic treatment methods and coordinated products, those affected can positively influence the side effects such as itching and tightness of the skin - especially when there are no relapses.
Moisturizing, soap-free washing additives and oil baths - In the case of both diseases, it should first be noted that frequent showering or bathing tends to have a negative effect. Incorrect cleaning of the skin can, among other things, trigger acute attacks. Soap-free detergent additives or oil baths are recommended.
Moisturizing creams that strengthen the skin barrier - an appropriate basic care is essential for the treatment. This includes regular care of the skin with moisturizing creams that strengthen the skin barrier. The rule here is: it is better to apply a thin layer of cream to the skin several times a day than to apply a thick layer twice a day! This can often provide relief from itching.
Care for sensitive skin - For these care products, it is essential that their active ingredients are incorporated into low-irritant (e.g. without dyes, fragrances, parabens, mineral oil, PEG derivatives) bases. As a rough guideline, products from series are best suited for “sensitive skin”.
Rich creams with natural oils - Rich creams with valuable natural oils (e.g. evening primrose oil) and vitamin E. Oils with high proportions of unsaturated fatty acids such as GLA (gamma-linolenic acid) are able to positively influence the putty substance of the stratum corneum and have a positive effect to strengthen the barrier function of the skin. The sensitive epidermis becomes less permeable and irritants are prevented from "entering".
The fatty oil of the evening primrose is often used to treat itchy skin and eczema and to stabilize the skin barrier. When applied locally, the essential fatty acids can be integrated into the lipid structures of the skin and support the cohesion of the stratum corneum there.
Another special oil is echium oil, because it is very rich in essential fatty acids. The most important component for eczematic skin is stearidonic acid. It is included at over 12%. This value is a multiple of the content of conventional omega-3 oils. As a precursor to eicosapentaenoic acid and prostaglandin PGE 3, it has excellent anti-inflammatory properties. Another component of echium oil is gamma-linolenic acid. The oils improve barrier properties and reduce TEWL (transepidermal water loss).
In some cases, the extract of the balloon vine can support the diseased skin. In pharmacy, it is used as an anti-inflammatory and anti-itchy herbal counterpart to cortisone in the care of eczematic skin, neurodermatitis and psoriasis. The anti-inflammatory, anti-irritant effect is also used with great success in cosmetic products.
Another addition to these creams should be moisturizing actives. Urea supplements hold moisture in the skin, make it smoother, and even relieve itching in some patients. However, urea-containing creams can cause a burning sensation on the skin in acute eczema.
Desquamation of the foci of inflammation - A therapeutic goal in psoriasis is to control the symptoms, especially inflammatory reactions, itching and flaking (cornification disorders). In order for a local therapy to work properly, desquamation ("keratolysis") of the foci is first necessary. This is done with creams containing salicylic acid, urea ointments or baths with oil or brine. Salicylic acid has the further advantage that it not only has a keratolytic effect, but also has a slight anti-inflammatory effect. In both diseases, it is important to stop the vicious circle of itching.
At a glance
Psoriasis and neurodermatitis are inflammatory skin diseases that are hereditary. Both are associated with itching and occur in flares.
Neurodermatitis occurs more on the flexor sides, but also on the face and neck, psoriasis more on the extensor sides.
Neurodermatitis shows up on the skin with different degrees of reddening (weeping, blisters, dry or leathery), psoriasis usually with coarse, silvery flaking on reddened skin and sharply delimited.