Psoriasis Causes and Treatment

Symptoms

Psoriasis is a chronic inflammatory, benign, and noninfectious skin disease. It manifests as symmetrical (bilateral), sharply demarcated, bright red, dry, raised plaques covered by silvery scales. Typically affected areas are the elbows, knees, and scalp. Itching, a burning sensation and pain are other symptoms, and scratching further aggravates the condition. Psoriasis can also affect the joints (psoriatic arthritis) and the nails (nail psoriasis). Because the skin has an important communication function, the disease represents a psychological burden for those affected and has a negative impact on their quality of life. Several manifestations are distinguished. This article focuses primarily on plaque psoriasis.

Causes

Psoriasis is caused by a change in skin cells (keratinocytes) that leads to hyperproliferation, incomplete differentiation, and hyperkeratosis. At the same time, immune cells also migrate, blood vessels dilate and vascularization is stimulated. In contrast to normal skin, in which the skin cells of the epidermis migrate from the stratum basale to the stratum corneum within about four weeks, this process takes only about three to five days (!) in psoriasis. The stratum granulosum is absent and cell nuclei are found up to the uppermost layer. Major causes include:

  • Heredity (genetics)
  • Immune and inflammatory response: T lymphocytes, mediators such as cytokines.
  • Triggers: e.g. infections, stress, skin lesions, drugs such as lithium, antimalarials, NSAIDs, steroid withdrawal, beta blockers.

Diagnosis

Diagnosis is made in dermatology or family medicine usually on the basis of the clinical picture and less frequently with a biopsy. Other skin diseases must be excluded.

Nonpharmacologic treatment

  • Skin care, mild soap
  • Baths
  • Phototherapy, e.g. UV treatment, sun exposure, PUVA, laser treatment.
  • Avoid triggers
  • Fish treatment: Garra rufa

Drug treatment

Psoriasis is not yet curable, but can be relieved with topical and systemic antipsoriatic (anti-dandruff) agents: Topical glucocorticoids:

  • Such as mometasone furoate or clobetasol propionate, are among the most commonly prescribed agents for topical treatment and are available in various dosage forms. They have anti-inflammatory, antipruritic, antiallergic, and antiproliferative properties. One difficulty is the potential adverse effects associated with excessive use. Glucocorticoids such as triamcinolone are also rarely injected directly into the lesions.

Vitamin D derivatives:

  • Such as calcipotriol (Xamiol, Daivobet), calcitriol (Silkis) and tacalcitol (Curatoderm) are also commonly used for topical therapy. They inhibit epidermal cell proliferation and promote normal keratinization. The drugs are often combined with topical corticosteroids.

Skin care products:

  • Like are recommended for regular care and restore the skin barrier.

Keratolytics:

  • Such as salicylic acid and urea (eg Kerasal, Magistral formulations) dissolve the horny layer thickening and make the skin soft and supple again. See also under salicylaseline.

Anthranoids:

  • Dithranol (anthralin) is no longer on the market in many countries.

Psoralens (coumarins):

Immunosuppressants are used mainly in severe disease progression:

Biologics: interleukin-17 receptor inhibitors:

Interleukin-23 inhibitors:

  • Guselkumab (Tremfya)
  • Risankizumab (Skyrizi)
  • Tildrakizumab (Ilumetri)

Interleukin-17A inhibitors:

Interleukin-12 and interleukin-23 inhibitors:

  • Ustekinumab (Stelara)

TNF-alpha inhibitors:

  • Adalimumab (Humira)
  • Etanercept (Enbrel)
  • Golimumab (Simponi)
  • Infliximab (Remicade)

Phosphodiesterase-4 inhibitor:

Topical calcineurin inhibitors:

Retinoids:

Fumarate:

Tars:

Herbal antipsoriatics:

  • Capsaicin
  • Mahonia aquifolium (e.g. Omida Rubiderm-N)