Successful treatment of severe acrodermatitis continua of hallopeau with Bimekizumab: A case report

Abstract

Acrodermatitis continua of Hallopeau is a rare form of pustular psoriasis affecting the acral fingers and toes, characterized by recurrent eruptions of sterile pustules that lead to significant pain and potentially irreversible destruction of the nail apparatus. Symptoms are often refractory to topical and systemic therapies for psoriasis. This case report presents a healthy 23-year-old female with severe acrodermatitis continua of Hallopeau, destructing all 10 fingernails. Treatment with Bimekizumab, a monoclonal antibody that inhibits interleukin-17, led to 50% improvement by 2 months, and complete normal regrowth of all fingernails by 1 year. The medication was tolerated well without any reported side effects. This is the second reported case of successful acrodermatitis continua of Hallopeau treatment with Bimekizumab, highlighting its potential as an effective and safe option for this challenging and recalcitrant condition.

Introduction

Acrodermatitis continua of Hallopeau (ACH) is a rare variant of pustular psoriasis primarily affecting the acral fingers and toes. It is characterized by recurrent sterile pustules around the nails, which can lead to significant pain, inflammation, and irreversible destruction of the nail apparatus. Over time, these pustules may coalesce to form larger collections of pus and may spread proximally to involve the dorsal aspects of the hands and feet. ¹ ACH is often resistant to conventional topical and systemic therapies for psoriasis, posing a significant therapeutic challenge. Recent insights into pustular psoriasis have revealed dysregulation in neutrophil and keratinocyte-driven inflammatory pathways, including mutations in the genes encoding interleukin-36 (IL-36), IL-17, CARD14, and AP1S3. ² This pathophysiology is shared by other pustular skin diseases, such as generalized pustular psoriasis and palmoplantar pustulosis. Bimekizumab, a monoclonal antibody that inhibits both IL-17A and IL-17F, has shown promise in treating these conditions by targeting these key inflammatory pathways.

Here, we present a case of severe ACH successfully treated with Bimekizumab, marking the second reported case of its use for this condition. ³ This case highlights Bimekizumab’s potential as an effective and safe treatment option for ACH, a rare and difficult-to-treat disease that often defies conventional approaches. Written patient consent was obtained for this study.

Case description

A 23-year-old woman presented to the emergency department in early 2023 with acute pain, swelling, and progressive destruction of her fingernails. She had a prior history of mild psoriasis managed with topical steroids, with the current flare-up triggered by a stressful life event. Examination revealed near-complete destruction of all 10 fingernails, accompanied by erythema, scaling, and pustules (Figure 1). Additional findings included erythematous plaques with white micaceous scales on the scalp. A clinical diagnosis of ACH and plaque psoriasis was made. Family history was notable for psoriasis affecting multiple relatives. The patient was otherwise healthy and not taking any medications.

Figure 1.

Presentation of ACDH.

Given the rapid progression of the condition and significant morbidity, systemic therapy was pursued. The patient expressed plans for a future pregnancy, which precluded the use of the traditional systemic treatments acitretin and methotrexate. Initially, she was co-managed with topical calcipotriol/betamethasone dipropionate and lemborexant for sleep disruption while awaiting coverage and through the first month of treatment with Bimekizumab in June 2023.

By 2 months of treatment, she reported a 50% improvement in her nail appearance and pain (Figures 2 and 3). By 1 year, she was asymptomatic, and on clinical exam, she had 100% resolution with complete normal regrowth of all nails. The treatment was well tolerated, with no reported adverse effects. One year after treatment initiation, the patient became pregnant. The risks and benefits of continuing Bimekizumab during pregnancy were discussed. After careful consideration, the patient chose to continue the treatment. At the time of this report, she is 6 months pregnant without any notable adverse effects to the pregnancy.

Figure 2.

After 2 months of treatment.

Figure 3.

After 2 months of treatment.

Discussion

Due to the rarity of ACH, there are no standardized treatment guidelines and treatment is often refractory to traditional topical and oral psoriasis therapies. ²

Multiple case reports and studies have highlighted the potential for biologic therapies, such as IL-12/23, IL-23, IL-1, IL-36, IL-17, and TNF-α inhibitors, to offer rapid and sustained improvement in ACH. Based on a recent systematic review of case reports, IL-12/23 inhibitors (ustekinumab) and IL-23 inhibitors (guselkumab and risankizumab) showed the highest frequency of improvement, with a complete resolution of 52.6% (n = 10/19) of cases within 22.4 weeks. TNF-α inhibitors (infliximab, adalimumab, and etanercept) showed the second highest frequency of improvement, albeit with a higher incidence of adverse events or lack of sustained response. IL-17 inhibitors (ixikizumab, secukinumab, and brodalumab) had the lowest frequency of improvement of the biological classes. ⁴ However, this review did not include Bimekizumab given the lack of published cases at the time. By the time of this report, there was one other reported case in the literature for ACD treated with Bimekizumab with a complete response noted at just 2 months. ³ Theoretically, through its broader mechanism of action targeting both IL-17A and IL-17F, this medication may have superior efficacy in treating ACH and other forms of pustular psoriasis compared to other IL-17 inhibitors. Experimental studies have shown that Bimekizumab can normalize the elevated levels of IL-36 expression, a key player in the inflammatory pathways of pustular psoriasis, in psoriatic plaques to levels in non-lesional skin. ⁵

Conclusion

This case adds to the growing body of evidence supporting Bimekizumab as an effective and safe treatment for ACH, especially in patients who have not responded to or are contraindicated for conventional therapies. This is the second reported case of Bimekizumab for ACH, and our patient had complete normal nail regrowth by 1 year. Based on its broader inhibition of IL-17A and IL-17F and potential inhibition of IL-36, ⁵ Bimekizumab may have greater efficacy for variants of pustular psoriasis such as ACH, which frequently carry IL-36 mutations. Ongoing research, ideally prospective and randomized trials, is required to further assess the efficacy of Bimekizumab in pustular psoriasis and ACH specifically. Lastly, while our patient had no noted adverse events during her pregnancy up to 6 months, further research into the safety of Bimekizumab in pregnancy is required.