Type III juvenile pityriasis rubra pilaris: a successful treatment with infliximab

Emerging Role of Biologic Drugs Targeting IL-17 and IL-23: Pityriasis Rubra Pilaris

Pityriasis rubra pilaris (PRP) is a rare, papulosquamous, inflammatory skin disease. PRP represents a therapeutic challenge. The rarity of this disease and its possible spontaneous remission makes the conduction and interpretation of therapeutic studies particularly difficult. Moreover, PRP not infrequently proves resistant to common topical and conventional systemic therapies. In this context, numerous biologic agents have been reported in PRP treatment. The aim of our manuscript was to review the current literature to evaluate the possible role of biologics targeting the IL17/23 axis in PRP management. Recent cases in the literature have highlighted the use of several promising drugs: IL-17 inhibitors, IL-23 inhibitors, and the IL-12/23p40 inhibitor ustekinumab. However, it should be noted that all these drugs are approved for moderate-to-severe plaque psoriasis and their use in PRP is off label. The treatment of PRP is based on clinical experience, case reports or case series reported in the literature, as randomized controlled trials are difficult to conduct due to the rarity of the condition. Despite data on the efficacy of drugs targeting IL-17 and IL-23 being promising, they are still limited. Certainly, further studies are desirable to better characterize PRP and establish shared guidelines.

Treatment Options for Juvenile Pityriasis Rubra Pilaris

Pityriasis rubra pilaris represents a group of familial and acquired disorders of cornification that affect both adult and pediatric patients. Treatment options are difficult to assess through clinical trials, given the rarity of the disorder and its tendency for spontaneous remission. Case reports and case series are therefore the primary means of assessment. Because of the heterogeneity of the disease, there is no universal approach to treatment, and multiple agents may need to be trialed to achieve disease control. At present, topicals are used for most pediatric patients, though monotherapy with topicals is only effective for less severe disease. Despite concerns over their side-effect profiles, oral retinoids are generally accepted as a first-line systemic therapy. However, interleukin-17 inhibitors and ustekinumab, an interleukin-12 and interleukin-23 inhibitor, may soon become first-line systemic treatment as well, given their efficacy and relative safety in trials thus far. Ustekinumab, in particular, is emerging as a first-line agent for patients with pityriasis rubra pilaris with CARD14 gene variations. When these therapies fail, second-line and adjunctive therapies to consider include tumor necrosis factor-alpha inhibitors, methotrexate, and phototherapy. However, further investigation is necessary to assess the safety and efficacy of many of these agents in juvenile pityriasis rubra pilaris.

Systemic therapies of pityriasis rubra pilaris: a systematic review

Pityriasis rubra pilaris (PRP) is a rare papulosquamous disorder. Treatment is challenging; the armamentarium consists of topical corticosteroids, phototherapy, classic systemic treatments such as retinoids or immunosuppressive drugs, and most recently biologicals. However, the relative effectiveness of therapies is unclear. Our objective was to review the published literature on systemic treatment of PRP. A systematic review was conducted on PubMed and the Cochrane Library up to 5 September 2017. Studies evaluating any systemic treatments of PRP (except for historical treatments) were included. Overall, 182 studies met the predefined inclusion criteria, and reported on 475 patients and 652 courses of treatment. 42.0 % (225/514) of all patients treated with retinoids achieved an excellent response (isotretinoin: 61.1 % [102/167], etretinate: 47 % [54/115], and acitretin: 24.7 % [43/174]) compared to an excellent response rate of 33.1 % (53/160) with methotrexate. Therapy with biologicals was successful in 51.0 % of patients (71/133) (ustekinumab: 62.5 % [10/16], infliximab: 57.1 % [28/49], etanercept: 53.3 % [16/30], and adalimumab: 46.4 % [13/28]). This review balances effectiveness, side effects, experience, and drug costs in order to suggest a treatment regimen starting with isotretinoin as first-line, methotrexate as second-line and biologicals as third-line treatment for this difficult-to-treat dermatosis.

Long-term ustekinumab treatment for refractory type I pityriasis rubra pilaris

BACKGROUND

Pityriasis rubra pilaris is a rare, chronic erythematous squamous disorder of unknown etiology. The disease is characterized initially by small follicular papules that coalesce into yellowish pink scaly plaques, palmoplantar keratoderma, diffuse furfuraceous scale of the scalp, and frequent progression to exfoliative erythroderma. Generally it is difficult to discern pityriasis rubra pilaris from other skin conditions but key-clinical features help in the diagnosis such as "islands" of spared skin within generalized erythroderma, follicular keratotic plugs, and an orange hue of the involved skin. Treatment options include topical vitamin D analogues, keratolytics, systemic acitretin, methotrexate, cyclosporine, azathioprine, fumaric acid esters, phototherapy, and anti-TNFα agents. Cases, of pityriasis rubra pilaris, successfully treated with a short-course ustekinumab therapy, have been reported.

MAIN OBSERVATIONS

We report a 31-year-old man with pityriasis rubra pilaris, refractory to conventional treatments, successfully treated with ustekinumab monotherapy for over 64 weeks. After failing conventional systemic agents (cyclosporine, aciretin and methotrexate), ustekinumab 45 mg has been prescribed, with the same dosing regimen as in psoriasis. The patient improved dramatically within 4 weeks of the first injection, with markedly less erythema and pruritus. Long-term control of the disease of the disease was achieved (64 weeks of treatment).

CONCLUSION

We report this case in order to show the striking and rapid efficacy of ustekinumab in reducing the signs and symptoms of the disease. Complete remission was achieved after the third injection, but also a long-term control of the disease. The therapy was well-tolerated in our patient and no adverse events occurred.

Infliximab in the treatment of plaque type psoriasis

Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-α drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-α has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis.