A clinical review of phototherapy for psoriasis

Abstract

Psoriasis is an autoimmune inflammatory skin disease. In the past several decades, phototherapy has been widely used to treat stable psoriatic lesions, including trunk, scalp, arms and legs, and partial nail psoriasis. A variety of light/lasers with different mechanisms of action have been developed for psoriasis including ultraviolet B (UVB), psoralen ultraviolet A (PUVA), pulsed dye laser (PDL), photodynamic therapy (PDT), intense pulsed light (IPL), light-emitting diodes (LED), and so on. Because light/laser each has specific therapeutic and adverse effects, it is important to adequately choose the sources and parameters in management of psoriasis with different pathogenic sites, severities, and duration of the disorder. This review aims at providing most updated clinic information to physicians about how to select light/laser sources and individual therapeutic regimens. To date, UV light is primarily for stable plaque psoriasis and PDL for topical psoriatic lesions with small area, both of which are safe and effective. On the other hand, PUVA has better curative effects than UVB for managing refractory psoriasis plaques, if its side effects can be better controlled. PDL provides optimal outcomes on nail psoriasis compared with other lasers. Although the trails of low-level light/laser therapy (LLLT) are still small, the near infrared (NIR) and visible red light with low energy show promise for treating psoriasis due to its strong penetration and encouraging photobiomodulation. IPL is rarely reported for psoriasis treatment, but PDT-IPL has been found to offer a moderate effect on nail psoriasis. In brief, various phototherapies have been used either in different combinations or as monotherapy. The modality has become a mainstay in the treatment of mild-to-moderate psoriasis without systemic adverse events in today’s clinical practice.

Quantification of histopathological changes in patients with psoriasis before and after phototherapy

“…PUVA therapy is preferably indicated as a second‐line treatment for large thick plaques involving extensive psoriasis. UVB‐NB phototherapy is recommended as a first‐line treatment (level of evidence A) in adults with extensive and moderate psoriasis with smaller and more superficial plaques, presenting few immediate adverse effects, lower risk of drug‐induced photosensitivity, and without need for ocular photoprotection after treatment …”

“…Absence of granular layer treatment. 23,24 The histopathological analysis is usually descriptive, focusing on just a few aspects present in psoriasis. 3,15,16,25 Hence, further studies that observe histopathological changes through total scores are required, constituting a comprehensive quantitative method.…”

Rapamycin ameliorates psoriasis by regulating the expression and methylation levels of tropomyosin viaERK1/2 andmTORpathways in vitro and in vivo

“…Psoriasis is one of the most serious autoimmune diseases with numerous of obvious pathological changes in the lesional skin, including epidermal abnormal proliferation, aberrant differentiation and so on, and these events would induce erythematous plaques on the patient's skin, which is itchy and even very painful. [12,[30][31][32] Due to the complex pathogenesis of psoriasis, there are very few effective treatments for the patients of psoriasis. [30,33,34] Traditionally, various topical therapies can be used to treat the patients with mild disease of psoriasis, such as topical retinoids, corticosteroids, vitamin D and its analogues.…”

Treatment of psoriatic skin lesions with a new Er:Yag laser technology: A case series study

“…Patients are selected for SMA method treatment on the basis of the same principles that are used for other laser and phototherapy methods of treating psoriasis: the main indication is symptoms of psoriasis vulgaris or inverse psoriasis that have been developing stably. Laser and photo treatment is not recommended for widespread and unstable psoriasis vulgaris or for drop‐shaped, pustular, or erythrodermic psoriasis (Zhang & Wu, ).…”

“…Laser and photo treatment is not recommended for widespread and unstable psoriasis vulgaris or for drop-shaped, pustular, or erythrodermic psoriasis (Zhang & Wu, 2017).…”