Topical drug therapy is one of the main methods indispensable in the treatment of psoriasis, with the advantages of safety, low transdermal absorption and low systemic adverse effects, and is applicable to the majority of psoriasis patients.
Most patients with mild to moderate psoriasis can adequately control the disease with topical drugs or phototherapy alone, and the maintenance period of topical drugs for patients with moderate to severe psoriasis can delay relapse.
Topical treatment drugs include retinoids, glucocorticosteroids, etc. What are the specific indications, methods of use, improvement effects, and possible adverse effects in the course of treatment? Next, let’s take a look.
Retinoic acid drugs
1.Vitaminic acid drugs
Effects and indications: Retinoic acid drugs can reduce the epidermal inflammatory response, promote the normal differentiation of epidermal cells and inhibit the proliferation of sebaceous cells, and can selectively bind receptors, regulate the transcription of psoriasis-related genes, thereby inhibiting epidermal proliferation and regulating epidermal keratinocyte differentiation.
The commonly used topical retinoids are 0.05% and 0.1% tazarotene ointment, which are suitable for resting plaque psoriasis with a body surface area of <20%, trunk and extremities.
Adverse effects and precautions: Local skin irritation can occur during treatment with retinoids, so they should be avoided on the face, around the eyes, vulva and skin folds, and are contraindicated in pregnant and lactating women. Their safety and efficacy in pediatric and adolescent populations have yet to be confirmed, and the level of evidence for topical retinoids in the treatment of psoriasis in children is V.
Glucocorticoids
2.Glucocorticosteroids
Actions and indications: Glucocorticoids can exert anti-inflammatory, anti-proliferative and immunosuppressive effects and are usually well tolerated.
Weak glucocorticosteroids are usually used on the face, neck, folds, external genitalia and children’s diaper area.
Moderately potent glucocorticoids are mostly used on the scalp, trunk and extremities.
Ultra-potent glucocorticoids are generally limited to hypertrophic, palmoplantar lesions or recalcitrant lesions that have failed to respond to treatment.
Medium- and strong-acting glucocorticoids are recommended for plaque psoriasis, while weak- and medium-acting glucocorticoids are recommended for pustular psoriasis and erythrodermic psoriasis to prevent exacerbation of the disease by stimulation.
Adverse reactions: Common adverse reactions of glucocorticoids include skin atrophy, capillary dilation, atrophic lines, purpura and hirsutism. Although glucocorticosteroids have more adverse reactions, topical glucocorticosteroids have landmark significance in the treatment of skin diseases, especially in the treatment of psoriasis.
Precautions: When topical hormones are used, it is necessary to avoid sudden discontinuation of the drug after the lesions are basically controlled, and in principle, the dosage should be gradually reduced after obvious curative effects are achieved. The time limit for using super-potent glucocorticoids is usually 2-4 weeks, and long-term continuous use is not advocated.
At the same time, intermittent, combined, rotating and sequential treatment strategies can be used to avoid adverse reactions caused by long-term or continuous topical application.
3.Vitamin D3 derivatives
Actions and indications: Vitamin D3 derivatives were applied in clinical practice in the 1990s, with good efficacy and low toxicity, and soon became the first-line drugs for psoriasis treatment.
Its alternate application with glucocorticosteroids is the classical scheme of topical drug treatment for psoriasis.
In addition, for patients with moderate-to-severe psoriasis, vitamin D3 derivatives can be combined with phototherapy narrow-spectrum medium-wave ultraviolet light or combined with systemic drugs to enhance the efficacy and reduce the adverse effects of the respective drugs.
Adverse effects and precautions: Common adverse effects of vitamin D3 derivatives are local irritation, such as erythema and pruritus. Excessive doses may lead to hypercalcemia or hypercalciuria, so these drugs are often prescribed with a maximum weekly dose, and patients need to be monitored for blood calcium and renal function when necessary.
References
[1] Yao XY, Zhao K, Wang MY, et al. Development history and insights of topical drugs for psoriasis [J]. Chinese Journal of Frontiers in Medicine (Electronic Edition),2021,13(12):19-24.