The exact cause of psoriasis is still unknown, but it is clear that the joint existence of more than one factor is required for the illness to develop. In addition to a hereditary component, there are specific psoriasis triggers.
Some triggers are external, such as injuries (burns, insect bites, tattoos, surgical operations). Other triggers are internal, such as various infections by fungi and bacteria, other types of skin inflammation (e.g., allergic eczema, viral infections).
A very significant category of internal trigger is the chronic, non-acute inflammation, such as chronic inflammation of the prostate, tonsils, ovaries, abscesses of the gum, chronic sinus inflammation. Often, the appearance of psoriasis indicates the existence of a previously unnoticed illness.
Certain medications and alcohol consumption can provoke psoriasis. The role of stress is also significant, as are psychological factors.
The series of events in the inflammatory and immunological process behind the symptoms of psoriasis are quite well understood.
Skin cells normally arise in the lower layers of the epidermis. They later migrate to the surface, accumulate keratin, gradually lose their nuclei and interconnectivity, and are unnoticeably shed. In psoriasis, the migration of the skin cells accelerates significantly, leaving no time for the above process: skin cells which still contain their nuclei and are interconnected begin to pile up, causing the characteristic white scales.
These changes appear to be triggered by an immune process, in which particular white blood cells (active T cells) have a leading role. Research is focused on understanding the exact molecular process and developing medications to prevent the development of psoriatic symptoms.
The lesions of psoriasis can be as small as 1-2 cm in size, but typically are larger and merge into so-called plaques. The plaques are distinct from the healthy, surrounding skin, their surface is covered with waxy white, peeling scales. The symptoms appear typically on the elbows, knees and scalp. Tiny needle-like marks may appear on the nails.
The lesions of psoriasis are not painful and generally do not itch. In about 5% of cases, the joints are affected and joint pain can precede the skin symptoms. The small joints of the hands, feet and the spinal joints can be affected, as well as the large joints – hip, knee, ankle, shoulder. This inflammation can later lead to deformities.
Some patients experience only small, 1-2 cm round lesions above their elbows and knees throughout their lifetime. In others, multiple palm-sized plaques cover virtually the entire body surface area. The variability of the symptoms is very characteristic: following an acute phase of several months, patients can be symptom-free for years. Improvement is expected in the summertime, but deterioration is expected in association with infections and significant stress.
Most patients due not present with changes in internal organs or laboratory values.
Since our genetic make-up is given, absolute prevention is not possible. We can attempt to prevent symptoms by protecting the skin from injuries and caring even for minor infections and skin fungi. Sunburn should be avoided, as well as medications that provoke psoriasis. Patients should understand the triggers of psoriasis and care for chronically inflamed tonsils, gums, etc.
Topical treatment is recommended in mild cases, scales are removed from the plaques using peelants (e.g., ointments containing 10% carbamides, 5-10% salicylic acid, salt baths). Dithranol solution of various concentrations is recommended to prevent the accelerated maturation of skin cells. Tar-containing preparations were used traditionally, but these are only very rarely used today. Steroid-containing ointments, creams and solutions can be used on the plaques to reduce inflammation. Vitamin-A analogues (calcipotriol, tacalcitol) are also recommended in ointment form.
Internal medications may be indicated in the case of more severe, very extensive psoriasis. Synthetic Vitamin A derivatives, the retinoids, are effective in normalizing the keratinizatin process.
Light therapy is also effective for psoriasis. Both the UVA and UVB bands are used. A variant of this is the use of a light-sensitive medication before treatment with UVA (PUVA) or the 311 nm wavelength UVB therapy (narrow-band UVB).
The physician clearly has multiple forms of treatment to choose from, as well as certain well-defined combinations. Treatment is determined for each patient individually depending on the severity of the symptoms and other illnesses.