52 Educational Learning
A Comprehensive Guide to Treating Moderate to Severe Psoriasis Learning Objectives Psoriasis is a chronic multisystem autoimmune disease with prominent skin manifestations and multiple potential co-morbidities such as arthritis, inflammatory bowel disease, cardiovascular disease, and depression. Moderate-severe psoriasis is usually defined by the extent of skin involvement, although special sites or significant impact on quality of life are also considered. Topical measures should still be utilised to manage more severe psoriasis, but advanced systemic and biologic therapies have revolutionised the management of psoriasis. Phototherapy involves use of ultraviolet B or A (in combination with the photosensitiser psoralen). Systemic agents for moderate-severe psoriasis include methotrexate, ciclosporin, apremilast, acitretin, and fumaric acidic esters. Biologic targets include tumour necrosis factor alpha, interleukin-12/23, interleukin-17, and interleukin-23 inhibitors. Oral steroids should never be used to treat psoriasis due to the significant risk of potentially serious rebound flares once they are stopped and given that extremely effective targeted agents are now available. Written by Dr Cathal O’Connor, RCPI dermatology specialist registrar in dermatology dual training in general paediatrics, ICAT paediatric dermatology fellow
Introduction Psoriasis is a chronic multisystem autoimmune disease with cutaneous involvement. It is characterised by the rapid growth of skin cells, leading to the formation of thick, red, and scaly plaques, although other presentations can occur. Approximately 73,000 people have psoriasis in Ireland. Individuals with moderate to severe psoriasis often experience significant physical and psychological co-morbidities. Most patients with psoriasis can be treated in primary care or in the outpatient setting. However, life-threatening presentations such as erythrodermic psoriasis or pustular psoriasis can require intensive inpatient management. While severe psoriasis should be managed by consultant dermatologists with access to advanced therapeutics, this article explores the various treatment options available for moderate to severe psoriasis, highlighting the importance of personalised and multimodal approaches. Understanding Moderate-Severe Psoriasis Psoriasis is driven by immune dysfunction that mistakenly targets healthy skin cells, triggering rapid cell turnover. This abnormal cell proliferation leads to the formation of plaques, commonly found on the elbows, knees, scalp, and lower back. Other patterns of psoriasis include guttate, flexural, pustular, and erythrodermic.
than 10% of the body surface affected, or a psoriasis area and severity index (PASI) over 10. Special sites that may warrant intensive treatment for localised disease include the face, palms and soles, and genitals. Additionally, individuals with severe psoriasis may be more likely suffer from arthritis, uveitis, inflammatory bowel disease, and cardiometabolic complications, highlighting the importance of a systemic approach to treatment. Systemic or biologic therapy should be considered for extensive disease, but topical treatments are often required for localised resistant areas, in tandem with these advanced therapies. Referral to Dermatology Referral to a dermatologist should be considered in the following settings: • The diagnosis is unclear • The response to topical treatment is inadequate • There is significant impact on quality of life • The patient has widespread severe disease (over 10% body surface area) • The patient has persistent involvement of ‘special sites’ – face, palms/soles, genitals • In cases of co-morbidities, psoriatic arthritis, referral and/ or collaboration with other specialties (eg rheumatology in the case of arthritis) Treatment Modalities Treatment for psoriasis can be prescribed in a step-wise ladder, with topical treatments for mild
Moderate to severe psoriasis is usually defined by the extent of skin involvement, with more MARCH 2024 • HPN | HOSPITALPROFESSIONALNEWS.IE
Figure 1
disease and phototherapy, systemic agents, or biologic agents for more severe disease (Figure 1). There are theoretically more potential side effects with immunomodulatory systemic or biologic medications given that they are administered systemically, although they are usually well tolerated when prescribed under the conscientious care of a dermatologist. Topical Treatments Emollients Hydration and emollients are valuable and inexpensive adjuncts to psoriasis treatment. Keeping psoriatic skin soft and moist minimizes the symptoms of itching and tenderness. Additionally, maintaining proper skin hydration can help prevent irritation and thus the potential for subsequent Koebnerisation (development of new psoriatic lesions at sites of trauma). There is no secret emollient of choice for
psoriasis, and patients should be led by which emollient they find most helpful. Corticosteroids Topical corticosteroids exert antiinflammatory, antiproliferative, and immunosuppressive actions. However topical corticosteroids have more limited ability to modify disease when used as monotherapy, so they are often combined with other topical preparations such as vitamin D analogues eg betamethasone/ calcipotriol foam. Less potent topical steroids such as hydrocortisone 1% or Eumovate should be used for facial and genital psoriasis due to greater propensity for skin thinning. There is no benefit to application more frequently than once daily, and adherence to greater than once daily topical corticosteroid therapy is very low. Topical corticosteroids generally can be continued as
