Psoriasis

Disease Overview

Psoriasis is a chronic inflammatory skin disease in which cells in the outer layer of the skin grow and move to the surface more quickly than normal due to a benign but uncontrolled increase in cell turnover. This leads to the formation of small to palm-sized patches of silvery-white scales.

Beneath these scaly areas, also known as plaques, the skin appears inflamed and reddened. The condition may be continuous or occur in recurring flare-ups, which are interrupted by symptom-free or low-symptom periods.

Flare-ups are often triggered by factors such as psychological or physical stress (e.g., infections, emotional strain) or hormonal changes.

Treatment of Psoriasis

Although psoriasis is not curable, it can be effectively managed. Treatment includes topical therapies (applied to the skin as creams, gels, or ointments) and systemic therapies (taken orally or administered by injection).

Medication Therapy

For mild to moderate psoriasis, affected skin areas are treated topically during the induction phase (initial high-dose treatment) with:

• Glucocorticoids (corticosteroids)

• Calcineurin inhibitors (tacrolimus, pimecrolimus)

• Dithranol

• Tazarotene (retinoid)

• Vitamin D derivatives

If more than 10% of the body surface is affected (severe psoriasis), systemic treatments may be used, including:

• Cyclosporine A (calcineurin inhibitor)

• Fumaric acid esters

• Methotrexate (MTX)

• Psoralens (as part of PUVA therapy)

• Acitretin (retinoid)

• Biologics (adalimumab, infliximab, etanercept, ustekinumab)

Glucocorticoids (corticosteroids) reduce inflammatory processes and suppress the immune system. They are naturally produced in the adrenal cortex and affect many tissues in the body. Long-term use may cause side effects such as metabolic disturbances, fluid retention, fat accumulation, muscle and bone loss, or acne. Therefore, high doses are typically used only initially.

Calcineurin inhibitors act as immunosuppressants. Tacrolimus and pimecrolimus have proven particularly effective in clinical trials for treating psoriasis lesions in sensitive areas such as the face and genital region. Cyclosporine A suppresses skin inflammation but is generally reserved for severe cases due to potential side effects affecting the liver, kidneys, and intestines.

Dithranol belongs to the group of antipsoriatic agents and has both anti-inflammatory and cell growth–inhibiting properties. Its effectiveness is often enhanced when combined with urea or salicylic acid in creams or ointments.

Retinoids support skin cell regeneration and inhibit plaque formation by slowing down cell division in affected areas. Tazarotene is used for mild to moderate cases, while acitretin is reserved for severe forms due to its stronger side effects.

Vitamin D derivatives such as calcipotriene or tacalcitol reduce inflammation and are commonly used topically.

Fumaric acid esters primarily reduce skin inflammation and are used systemically in severe cases that do not respond adequately to topical therapy.

Methotrexate (MTX), commonly used in cancer treatment, has also proven effective in moderate to severe psoriasis. It inhibits cell division by interfering with DNA synthesis.

If moderate to severe psoriasis cannot be adequately controlled with other treatments, biologics may be considered. These target specific immune pathways and are generally well tolerated.

Additional Treatment Measures

To enhance the effectiveness of medications, treatments are often combined with supportive measures such as salt baths to relieve skin irritation or the use of special fish (ichthyotherapy) that remove loose scales and prepare the skin for topical treatment or light therapy.

Light therapy uses UVA radiation to counteract inflammatory processes. In many cases, psoralens are applied beforehand to increase the skin’s sensitivity to light (PUVA therapy).