Recalcitrant anal and genital pruritus treated with dupilumab

Anal pruritus: Don’t look away

Anal pruritus is a common anorectal symptom that can significantly impair a patient’s quality of life, including their mental health. It can be one of the most difficult proctological conditions to treat. Patients often delay seeking medical attention, since it is an embarrassing but non-life-threatening situation. Pruritus ani can be associated with idiopathic and secondary causes, such as anorectal diseases, cancer (anal or colorectal), dermatological and sexually transmitted diseases, fungal infections and systemic diseases. If patients are referred for a colonoscopy, this can sometimes provide the first opportunity to evaluate the perianal area. Classifications of anal pruritus are based on the abnormalities of the perianal skin, one of the most commonly used being the Washington classification. A proper digital anorectal examination is important, as well as an anoscopy to help to exclude anorectal diseases or suspicious masses. Endoscopists should be aware of the common etiologies, and classification of the perianal area abnormalities should be provided in the colonoscopy report. Information on treatment possibilities and follow-up can also be provided. The treatment normally consists of a triple approach: proper hygiene, elimination of irritants, and skin care and protection. Several topical therapies have been described as possible treatments, including steroids, capsaicin, tacrolimus and methylene blue intradermal injections.

Dupilumab in Inflammatory Skin Diseases: A Systematic Review

Dupilumab was first approved for the treatment of atopic dermatitis (AD) and blocks the signaling of interleukin (IL)-4 and -13. Several other chronic skin conditions share mechanistic overlaps with AD in their pathophysiology, i.e., are linked to type 2 inflammation. Most recently, dupilumab was approved by the U.S. Food and Drug Administration for prurigo nodularis (PN). Given its relatively good safety profile, effective off-label use of dupilumab has been reported for a multitude of dermatologic diseases and several clinical trials for dermatologic skin conditions are currently ongoing. We conducted a systematic review of applications of dupilumab in dermatology other than AD and PN by searching the databases PubMed/Medline, Scopus, Web of Science and Cochrane Library as well as the clinical trial registry ClinicalTrials.gov. We found several reports for effective treatment of bullous autoimmune diseases, eczema, prurigo, alopecia areata, chronic spontaneous urticaria, Netherton syndrome and a variety of other chronic inflammatory skin diseases.

Successful use of dupilumab for the treatment of atopic dermatitis on the genitals, a neglected anatomical site

Atopic dermatitis (AD) is a chronic inflammatory disease that may involve any cutaneous site; involvement of the genital area may greatly impair patients' quality of life but, as the inspection of genitals is not usually conducted during the routine physical examination of patients with AD, the genital presentation of AD is frequently neglected and under-reported. We decided to evaluate the incidence of genital AD in patients with moderate-severe AD and the relative response to anti-interleukin (IL)-4/IL-13 dupilumab. In our study, a high incidence of genital AD emerged but the use of dupilumab allowed a generalized improvement.

Prominent Role of Type 2 Immunity in Skin Diseases-Beyond Atopic Dermatitis

Type 2 immunity, illustrated by T helper 2 lymphocytes (Th2) and downstream cytokines (IL-4, IL-13, IL-31) as well as group 2 innate lymphoid cells (ILC2), is important in host defense and wound healing.¹ The hallmark of type 2 inflammation is eosinophilia and/or high IgE counts and is best recognized in atopic diathesis. Persistent eosinophilia, such as seen in hypereosinophilic syndromes, leads to fibrosis and hence therapeutic Type 2 inhibition in fibrotic diseases is of high interest. Furthermore, as demonstrated in cutaneous T cell lymphoma, advanced disease is characterized by Th1 to Th2 switch allowing cancer progression and immunosuppression. Development of targeted monoclonal antibodies against IL-4Rα (eg, dupilumab) led to a paradigm shift for the treatment of atopic dermatitis (AD) and stimulated research to better understand the role of Type 2 inflammation in other skin conditions. In this review, we summarize up to date knowledge on the role of Type 2 inflammation in skin diseases other than AD and highlight whether the use of Type 2 targeted therapies has been documented or is being investigated in clinical trials. This manuscript reviews the role of Type 2 inflammation in dermatitis, neurodermatitis, IgE-mediated dermatoses (eg, bullous pemphigoid, chronic spontaneous urticaria), sclerodermoid conditions and skin neoplasms.

The emerging role of dupilumab in dermatological indications

INTRODUCTION

Dupilumab represents a breakthrough in the management of atopic dermatitis (AD), thanks to its powerful T-helper (Th)2-mediated immunity modulating activity. It can reduce the atopic skin molecular signature and induce a significant decrease in the clinical signs and symptoms of AD patients.

AREAS COVERED

Th2 activation has been confirmed or suspected in skin diseases other than AD, and several reports about the treatment with dupilumab in these conditions have been published. In order to review the new indications of dupilumab in dermatology, we performed a search on PubMed, Embase, Cochrane Skin databases, and clinicaltrials.gov.

EXPERT OPINION

The analysis of available literature suggests that dupilumab may have a large application in dermatology, besides AD. Clinical trials are underway on some widespread disease (i.e. chronic urticaria, bullous pemphigoid, alopecia areata, or allergic contact dermatitis). The data are still partial, but they seem to indicate that dupilumab is efficacious and safe. On the other hand, the dupilumab use in some rare skin diseases remains only hypothetical or linked to few case reports. Dupilumab could have a prominent position in the therapeutic algorithm of chronic skin diseases that significantly affect the quality of life of patients, require long-term treatment, or lacking effective therapies.

Treatment of patients with chronic pruritus of unknown origin with dupilumab

BACKGROUND

Chronic pruritus of unknown origin (CPUO) is a highly debilitating disease that lacks effective treatments. This study explores a new therapeutic strategy with dupilumab.

OBJECTIVES

To examine whether patients with CPUO demonstrate clinical response to dupilumab.

PATIENTS AND METHODS

This is a retrospective case series examining all patients with CPUO who were treated with dupilumab from March 2017 to December 2019 at a tertiary referral clinic at Washington University School of Medicine in St. Louis, MO. Numerical rating scale (NRS) itch score changes over time were recorded and analyzed.

RESULTS

Fifteen patients (67% women; mean [SD] age, 68.7 [12.6] years [range, 42-88 years]) were included in the analysis. All patients had a diagnosis of CPUO for a mean [SD] 2.6 [2.8] years. The median [IQR] pruritus NRS itch score before dupilumab injection was 8 [8-10] and the final median [IQR] NRS itch score was 1 [0-2.5]. The mean [SD] reduction in the NRS itch score was 7.0 [1.9]. Dupilumab was well tolerated with one report of mild injection site reaction that was self-resolving.

CONCLUSION

This study suggests that dupilumab may be an effective treatment for patients with CPUO and supports the design of future randomized placebo-controlled trials to prove its efficacy.

Dupilumab use in atopic dermatitis and beyond in skin diseases

Atopic dermatitis (AD) is a chronic inflammatory condition that affects 5-10% of adults and 9-18% of children and its pathology is rooted in the Th-2-mediated immune response. Dupilumab is a fully human IgG4 monoclonal antibody that targets the IL-4 receptor alpha subunit that is endogenously bound by the Th-2 cytokines IL-4 and IL-13. Successful clinical trials of dupilumab showing marked improvements in clinical signs of AD, patient reported symptoms and quality of life measures led to its approval for clinical use for moderate-to-severe AD in 2017. This review details the current body of evidence on the drug's mechanism of action, pharmacology, clinical efficacy and safety as well as post market and real world use.

Learning From Success and Failure: Biologics for Non-approved Skin Diseases

The impressive potential of biologics has been demonstrated in psoriasis, hidradenitis suppurativa, and urticaria. Numerous biologicals are entering the field for a restricted number of skin disorders. Off-label use of biologics in other recalcitrant skin diseases has increased. Mounting data point to the potential of already existing biologics acting on the IL-17/IL-23 pathway in skin disorders with epidermal hyperkeratosis (e.g., pityriasis rubra pilaris), acneiform inflammation (e.g., hidradenitis suppurativa), and loss of mucosal integrity (e.g., aphthosis). TNF-α blockers are also effective in the latter conditions but seem of particular value in granulomatous (e.g., granuloma annulare) and neutrophilic disorders (e.g., pyoderma gangrenosum). Failure of IL-17 blockade in skin diseases resulting from immune-mediated cell destruction (e.g., alopecia areata and vitiligo) illustrates its limited involvement in Th1-dependent skin immunology. Overall, disappointing results of TNF-α blockers in alopecia areata and vitiligo point to the same conclusion although promising results in toxic epidermal necrolysis suggest TNF-α exerts at least some in vivo Th1-related activities. Acting on both the Th1 and Th17 pathway, ustekinumab has a rather broad potential with interesting results in lupus and alopecia areata. The efficacy of omalizumab in bullous pemphigoid has revealed an IgE-mediated recruitment of eosinophils leading to bullae formation. Reconsidering reimbursement criteria for less common but severe diseases seems appropriate if substantial evidence is available (e.g., pityriasis rubra pilaris). For other disorders, investigator- and industry-initiated randomized clinical trials should be stimulated. They are likely to improve patient outcome and advance our understanding of challenging skin disorders.