Several treatment options are available for psoriasis, but the outcome of treatment is often not satisfactory. Psoriasis may be controlled either by topical or systemic therapy. Topical treatment involves the use of creams, lotions, gels and sprays on the skin surface and it has a localized effect. Systemic treatment is administered orally (tablets, capsules) or parenterally (injections). A complete cure for psoriasis has not as yet been achieved with any of the currently available medication.
When to start psoriasis treatment?
- Psoriasis patients who are asymptomatic during a period of remission may not require any treatment.
- Mild types of psoriasis affecting less than 10% of total body may be sufficiently controlled with topical treatment.
- Severe types of psoriasis affecting more than 20% of body usually require systemic therapy.
- Moderate and early stages of severe psoriasis may respond to topical therapy alone.
Phototherapy or combination of phototherapy with other forms of therapy is also an important treatment option in psoriasis.
Psoriasis Creams and Lotions
Corticosteroids for psoriasis
Topical corticosteroids are the main stay of the treatment for mild to moderate psoriasis. The steroids are available as creams, lotions, sprays, gels and ointments.
- Creams and lotions are preferred only if the psoriatic lesions are exudative in nature.
- Sprays and gels may be preferred for the lesions over the hairy areas of the skin.
- Ointments are preferred for dry psoriatic lesions.
These steroid applications are more effective when applied under occlusive covering – dressing that shields the affected skin from the environment. Clinically significant improvement may be seen after about 3 weeks of continuous use of steroids.
Types of steroids for psoriasis
Initially potent steroids like betamethasone 0.025%, dexamethasone 0.1%, clobetasol 0.05%, triamcinolone 0.1%, and so on are used. Use of potent steroids should be restricted only for initiation of therapy, and for severe and unresponsive lesions. Potent steroids should be used only for shorter period of time, and their sudden withdrawal should be avoided.
Generally twice daily application of steroids is sufficient, and application beyond two times a day does not provide additional benefit to the patient. Later the treatment may be shifted to less potent steroids like hydrocortisone 1% to 2%, mometasone 0.1%, fluticasone 0.05% and the frequency of steroid application may be reduced once the lesions diminish.
Side effects of steroids
Adverse effects associated with topical steroids include :
- thinning of skin
- increased risk of skin infections
- easy bleeding
- vascular malformations (striae and telangiectasia)
- suppression of pituitary and adrenal function
Risk of Cushing’s syndrome and other systemic effects of topical steroids are minimal.
Calcipotriene for psoriasis
Calcipotriene (calcipotriol) is a synthetic vitamin-D analogue. It suppresses the abnormal, excessive and rapid proliferation of the skin cells when applied topically. It also enhances the normal differentiation of the skin cells. Calcipotriene is particularly useful in controlling the chronic plaque type of psoriasis and its efficacy is similar to that of the moderate potency steroids.
Calcipotriene is available as 0.005% ointment, cream and solution. The medication is usually applied twice daily. Significant benefit is seen after about 1 to 2 months of the initiation of therapy. These results are greater when calcipotriene is combined with topical steroids as prescribed by a dermatologist.
Side effects of calcipotriene
Calcipotriene should not be used (contraindicated) in acute skin lesions of psoriasis. The side effects of calcipotriene includea : mild erythema, itching and scaling of the skin. Excessive skin irritation generally warrants discontinuation of the therapy. Calcipotriene does not interfere with the calcium metabolism but it is usually avoided in individuals with hypercalcemia and those with vitamin D toxicity.
Tazarotene for psoriasis
Tazarotene is a synthetic vitamin-A analogue (retinoid) which is available in gel form as 0.05 to 0.1%. It inhibits the proliferation of the cells when applied topically. This means that the overgrowth of skin cells leading to thickened plaques seen in psoriasis is reduced. It also has significant anti-inflammatory action.Tazarotene is effective in treating mild to moderate psoriasis with stable plaque lesions. It is more effective when combined with topical steroids and calcipotriene.
Side effects of tazarotene
Tazarotene is associated with higher degree of the skin irritation and may cause peeling of the skin. It should be avoided in the areas of acute or eczematous skin lesions, as it can cause severe irritation of the skin. It is contraindicated in the pregnant woman because of the risk of fetal deformity.
Keratolytics for psoriasis
The keratolytic agents dissolve intercellular matrix in the horny skin layer and are used to soften the dry thick skin lesions seen in psoriasis. The epidermal cells become swollen, smooth and eventually they desquamate with use of keratolytic agents.
- Salicylic acid is commonly used as a keratolytic agent. It is used as 10 to 20% solution which is applied twice daily.
- Other keratolytic agents are resorcinol (3% to 10%) and urea (5% to20%).
Emollients for psoriasis
Emollients are bland oily substances which are applied to the dry and cracked skin to soften the skin and produce smoothening effect. It forms a protective covering over the skin and restore elasticity of the skin. Commonly used emollients are sesame oil, olive oil, hard and soft paraffin, wax of bees and liquid paraffin.
Coal tar for psoriasis
Coal tar is a crude ointment preparation having several phenolic compounds which can induce remission of the psoriasis skin lesions in most of the patients. However there is high chance of relapse following discontinuation of coal tar therapy. The use of coal tar has declined due to its offensive smell, staining and irritant property, and due to the high incidence of allergic reactions associated with its use.
Anthralin for psoriasis
Anthralin reduces the skin lesions in psoriasis, but it is rarely used because of skin irritation, staining, severe itching and discoloration of the skin associated with its use. It may be occasionally used in combination with UV light therapy (phototherapy).
Phototherapy is beneficial in treatment of psoriasis. Natural or artificial ultraviolet light may be used for this purpose. Natural sunlight or artificial ultraviolet A or B (UVA or UVB) radiation either alone or in combination with photosensitizing drugs are used for treating psoriasis. Common adverse effects of phototherapy are redness, itching, skin irritation and skin burns. The adverse effects are of varying severity depending on the type of therapy. Long term exposure to UV radiation also increases risk of skin cancers.
Types of light therapy
Important phototherapy approaches include :
- brief exposure to the sunlight daily
- controlled exposure to artificial UVB radiatios for small localized lesions of mild to moderate psoriasis
- narrow band UVB therapy
- psoralen ultraviolet A (PUVA) therapy
PUVA for psoriasis
PUVA therapy is one of the most popular forms of light therapy utilized in the treatment of psoriasis. Psoralen sensitizes the skin to UV-A rays, whether from natural or artificial sources. Psoralens are taken orally (methoxsalen 0.4 to 0.6mg/kg) or applied topically (methoxsalen 1% solution) on the psoriatic lesions following which the patient is exposed to the UV-A rays. Such sessions are given 3 times a week, and several such sessions are required before any significant clinical improvement is seen.
UV-B for psoriasis
UV-B rays may also be used in combination with coal tar for treatment of psoriasis. This is known as Goeckerman regimen, named after the physician who made this treatment popular. This approach is not widely utilized these days as it is time consuming and modern drugs may be both more effective and convenient. Furthermore UV-B rays are associated with an increased risk of developing premature skin aging, sunburn and the increased risk of skin cancers.