Psoriasis

It is a chronic disease of the skin in which there is an alteration in the multiplication and differentiation of its cells. Its cause is unknown and approximately 30% of those who suffer from it have affected relatives.

It is accepted that there are genes that predispose to suffering from the disease and stimuli (trauma, infections, medications, climatic changes and emotional stress ) that make an outbreak appear or be more intense.

Symptoms of psoriasis

It affects approximately 1-2% of the population and can begin at any age.

Skin symptoms

Repeated outbreaks of well-demarcated erythematous plaques and papules covered by several layers of large, fine, pearly scales are characteristic.
There are many clinical forms:

• In small plates: the most frequent form. Appears on elbows, knees, and scalp.
• In large plaques: the lesions, more than 3 cm in diameter, are also located in the lumbosacral region.
• Psoriatic erythroderma: the entire skin surface is affected.
• Palmoplantar: affects palms and soles.
• Inverted: with lesions located exclusively in the skin folds.
• Guttata: very small lesions (less than 1 cm in diameter). It is more common in children and is usually triggered by a respiratory infection (usually tonsillitis).
• Generalized pustular psoriasis : it produces a rash all over the skin, without affecting the face, with erythematous plaques within which tiny pustules appear. It is associated with general malaise and fever and often affects the joints.
• Acropustulosis: pustules appear on the psoriasis plaques located on the fingers, with severe involvement of the nails.

Nail symptoms

The nails that are most frequently affected are those of the hands. The most frequent lesions are pitting and the most characteristic are the separation of the nail from the base of the finger to which it is attached.

Joint symptoms

They appear in approximately 5% of people with psoriasis. It consists of an inflammation of the joint that can be associated with lesions on the skin that covers it and, in some cases, with destruction of the bone with great deformation of the joint. The most frequent is the affectation of less than 4 joints of the hands and feet, being typical the appearance in the last joints of the fingers of the hand (those furthest from the hand).

How is it diagnosed?

Visualization of the lesions, their location and Koebner’s phenomenon is usually sufficient.

To support the diagnosis, a methodical Brocq scraping can be performed, which consists of successive detachments of the skin layers over a psoriatic lesion, successively appearing: pearly-white scales, a pink and shiny membrane and some spots bleeding.

Treatments for psoriasis

The disease can be improved but it cannot be cured. The treatments try to reduce the excess multiplication of the skin. The treatment will be different according to the personal circumstances of the patient (age, work, sociocultural environment) and the clinical form of the disease.

Topical treatments

• Emollients (oil in water, glycerin ): hydrate the surface layer of the skin, helping to eliminate scales and preventing cracks. Useful in all types of psoriasis.
• Keratolytics (salicylic acid, lactic acid): they eliminate the most strongly adhered scales, facilitating the penetration of other medications that we apply later.
• Useful on the scalp and nails. Be careful when using it in children, as they can cause burns.
• Derivatives of tar (anthralin): useful in plaques and, combined with UVB, in generalized affectation.
• Topical corticosteroids: anti-inflammatory effect. It is the most used treatment in small extensive psoriasis on the skin, scalp and folds. Long treatments should be avoided, especially in children, due to cutaneous side effects and absorption through the skin.
• Phototherapy: is the use of UVB radiation combined with the previous intake of oral substances (psoralens) in order to reduce the speed at which the surface layer of the skin is renewed. They are used in generalized plates and guttata.
• Derivatives of vitamin D (calcipotriol).

Oral treatment

• Retinoids (etretinate): are derivatives of vitamin A. Useful in severe cases. The most serious side effect is teratogenicity, so contraception is recommended for at least two years after stopping treatment.
• Methotrexate: useful in severe psoriasis.
• Cyclosporin A.

Can psoriasis be prevented?

The onset of the disease cannot be prevented, although the number of outbreaks and their intensity can be reduced by avoiding the mentioned triggers (trauma, infection, stress).

Before the appearance of erythematous plaques covered by large scales in areas characteristically subject to trauma: scalp, elbows, forearms, lumbosacral region, knees, hands and feet.