Acquired diffuse palmoplantar erythema with keratoderma in Chinese patients with pustular psoriasis: A predictor for IL36 receptor antagonist c.115+6T>C mutation?

Several studies have suggested that mutation of the interleukin 36 receptor antagonist gene (IL36RN) is related to generalized pustular psoriasis (GPP), and the presence of IL36RN mutation may affect the clinical manifestations and treatment responses. However, genetic testing is not routinely available in clinical practice for the diagnosis of GPP. Previously, GPP patients with acrodermatitis continua of Hallopeau (ACH) were found to have a high percentage of carrying IL36RN mutation. In this study, we reported six patients with pustular psoriasis presenting as diffuse palmoplantar erythema with keratoderma among 60 patients who carried IL36RN mutation. ACH was present in five patients and five patients had acute flare of GPP. This unique presentation may serve as a predictor for IL36RN mutation in patients with pustular psoriasis, similar to ACH.

A retrospective analysis of 65 patients with acrodermatitis continua of Hallopeau

There are limited data on acrodermatitis continua of Hallopeau (ACH), particularly among Asian populations. The primary aim was to evaluate the clinical features of ACH and treatment approaches in a sizeable multicentre Asian cohort. We analysed data from adult patients diagnosed with ACH. Of 65 patients with ACH, seven patients had ACH with GPP. Females were more frequently affected in both conditions. Five (71.4%) developed GPP 5-33 years after ACH onset, while two (28.6%) developed GPP concurrently with ACH. The onset age for ACH with GPP (27.9 ± 13.6 years) was earlier than that of isolated ACH (39.8 ± 17.3 years). Metabolic comorbidities were common. ACH exhibited a chronic persistent course. Among systemic non-biologics, acitretin was the most frequently prescribed, followed by ciclosporin and methotrexate. Acitretin and ciclosporin demonstrated similar marked response rates, which surpassed that of methotrexate. Regarding biologics, a marked response was more commonly observed with interleukin-17 inhibitors than with tumour necrosis factor inhibitors. Females are predominant in both conditions. The onset age for ACH among Asian patients is earlier (late 30s) than that for Caucasian patients (late 40s). Interleukin-17 inhibitors may be more effective than tumour necrosis factor inhibitors in managing ACH.

Successful treatment of acrodermatitis continua of Hallopeau coexisting with generalized pustular psoriasis with spesolimab: a case report

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory pustular dermatosis that presents as painful erythema with sterile pustules on nonacral skin. No unified standard and guideline for the treatment of GPP has been established. Several biologics have been tried for GPP, with varying success. Acrodermatitis continua of Hallopeau (ACH) is a very rare disabling variant of pustular psoriasis characterized by sterile pustules on the fingers and toes, including the nail bed. Comparatively, treating ACH is highly challenging due to its commonly therapy-resistant disease course. The pathogenic role of IL-36 signaling axis has been currently identified in GPP development. Spesolimab, the first anti-interleukin-36 receptor biologic, has been approved for treating GPP flares and shown promising results. In view of a shared pathogenesis between GPP and ACH, specolimab may be an effective treatment for ACH. Currently, there is no case and clinical trial data exist on this condition. Therefore, this case was aim to describe real-world experience of spesolimab use in ACH coexisting with GPP. We report an Asian patient with a 16-year-history of GPP and ACH with marked pustulosis on the nail bed and onychodystrophy. He received conventional systemic regimen acitretin, cyclosporine and biologics adalimumab and secukinumab, but experienced relapse for skin lesions and refractory for nail lesions. He was then treated with a single dose of spesolimab in combination with secukinumab, which resulted in skin clearance and nearly complete resolution of nail lesions over a 32-week period. Our observation suggests that spesolimab should be considered for the treatment of ACH, especially in the patients with intractable nail lesions and concomitant GPP.

Pustular psoriasis: A distinct aetiopathogenic and clinical entity

Pustular psoriasis is a distinct subset of psoriasis that presents with involvement of the skin in the form of sterile pustules along with systemic manifestations. Though it has been conventionally grouped under the umbrella of psoriasis, recent research has shed light on its pathogenetic mechanisms associated with the IL-36 pathway, which is distinct from conventional psoriasis. Pustular psoriasis in itself is a heterogeneous entity consisting of various subtypes, including generalised, localised, acute, and chronic forms. There is confusion regarding its current classification as entities like deficiency of IL-36 antagonist (DITRA) which are closely related to pustular psoriasis both in their pathogenetic mechanism and its clinical manifestations, are not included under pustular psoriasis. Entities like palmoplantar pustulosis, which presents with similar clinical features but is pathogenetically distinct from other forms of pustular psoriasis, are included under this condition. Management of pustular psoriasis depends upon its severity; while some of the localised variants can be managed with topical therapy alone, the generalised variants like Von Zumbusch disease and impetigo herpetiformis may need intensive care unit admission and tailor-made treatment protocols. The advent of newer biologics and better insight into the pathogenesis of pustular psoriasis has opened the way for newer therapies, including tumour necrosis factor-alpha inhibitors, interleukin-1 inhibitors, interleukin-17 inhibitors, and granulocyte monocyte apheresis. It continues to be an enigma whether pustular psoriasis is actually a variant of psoriasis or an entirely different disease entity, though we feel that it is an entirely different disease process.

Acrodermatitis continua of Hallopeau and generalised pustular psoriasis: Should they be the same or different entities?

Pustular psoriasis is characterised by eruptions of neutrophilic sterile pustules. The European Rare and Severe Psoriasis Expert Network consensus defines pustular psoriasis into three subtypes; generalised pustular psoriasis (GPP), palmoplantar pustulosis and acrodermatitis continua of Hallopeau (ACH). Mixed forms are categorised according to their predominant features. However, the Japanese Dermatological Association includes ACH under the diagnosis of GPP. This article aims to review the similarities and differences between ACH and GPP. Based on our review, interleukin (IL)-36RN mutations, the most frequent genetic findings in pustular psoriasis are found most commonly in GPP, followed by ACH. Genotypes of IL-36RN mutations among GPP patients and ACH patients are different between European and Asian ethnicities. IL-36 signalling pathway is the main mechanism. Metabolic diseases are common comorbidities and joint involvement can occur in 20.5%-36.4% of both conditions. Associated plaque psoriasis is more common in GPP than in ACH. Generally, ACH, even the generalised type, does not have systemic inflammation whereas GPP can occur with or without systemic inflammation. ACH can occur before, simultaneously, or after the development of GPP. However, response to treatment for GPP and ACH even in the same patients appear to be different. ACH seemed to be more recalcitrant to treatment than GPP but severe flare of GPP can lead to morbidity and mortality. Although GPP and ACH share genotypes and pathogenesis, we believe that ACH should be classified separately from GPP, and not under diagnosis of GPP. Future research is warranted to satisfactorily distinguish the two conditions.

Deficiency of interleukin-36 receptor antagonist (DITRA): An analysis of 58 Chinese patients in a tertiary hospital in Taiwan

DITRA, acronym for deficiency of interleukin-36 receptor antagonist (IL36RN), leads to unopposed pro-inflammatory signalling which typically manifests as pustular psoriasis. In Asian patients, c.115 + 6 T > C mutation is the most common and important single-nucleotide variant in DITRA. We present the largest case series consisting of 58 DITRA patients carrying heterozygous or homozygous c.115 + 6 T > C mutation. The mean age of onset (±SD) was 20.74 (±20.86), and the median age of onset was 13 years old. Twelve patients (20.7%) had disease onset before the age of two. Twenty-two patients (37.9%) had disease onset between the ages of 2-18. Main clinical phenotype was generalized pustular psoriasis (GPP) with systemic symptoms (33 patients, 56.9%), followed by acrodermatitis continua of Hallopeau (ACH) (16 patients, 27.6%). Nearly half of our patients (27 patients, 46.6%) ever had ACH, and only three of them are free of ACH currently, which indicates that the development of ACH is relatively persistent and irreversible. Thirty-four patients (58.6%) had recurrent GPP and 29 patients (50%) have been admitted due to GPP flare. Compared to those with heterozygous (C/T) mutation, more patients carrying homozygous mutation (C/C) have recurrent episodes of GPP (C/T vs. C/C: 25.53 vs. 76.47%, p = 0.0367). Two patients with squamous cell carcinomas arising from the pustular psoriasis skin lesions were noted. Two patients had elevated serum IgG4 levels.

Successful treatment of acrodermatitis continua of Hallopeau with tildrakizumab: A case report

Acrodermatitis continua of Hallopeau is a rare, localized variant of pustular psoriasis commonly associated with join disease and severe quality of life impairment. While there are no standard treatment guidelines, therapies used for psoriasis vulgaris are commonly tried. We report a case of severe acrodermatitis continua of Hallopeau in a patient with multiple comorbidities (advanced malignancy, recurrent empyema, psoriatic arthritis) where tildrakizumab lead to a rapid resolution of skin and joint disease which was maintained 1 year later. To date, there are only four cases reporting the use of IL-23 inhibitors class in acrodermatitis continua of Hallopeau and none for tildrakizumab. However, IL-23 inhibitors should be strongly considered among the treatment of choice for acrodermatitis continua of Hallopeau, especially in patients with ongoing malignancy and/or high risk of infections.

Targeting IL-17A for the treatment of pustular psoriasis: a comprehensive review

INTRODUCTION

Pustular psoriasis (PP) is a rare subtype of psoriasis. Overall, the growing evidence - in particular for acute generalized PP (GPP) - supports that it is a separate entity with a specific pathogenetic pathway. Interleukin (IL)-17/T-helper 17 (Th17) axis involvement may play an important role in the pathophysiology of PP. Biologicals, often required to achieve clinical remission, have changed the treatment of PP.

AREAS COVERED

We provide the reader with an overview of all the available evidence on the use of the antibody-based therapy targeting IL-17A in patients with PP.

EXPERT OPINION

Although papers reported in this review do not provide definitive evidence (due to methodological limitations) to support the use of IL-17 inhibitors as potential first-line for the treatment of PP, based on our own experience and according to most of the reported literature, targeting IL-17A, may represent the best therapeutical approach in this peculiar clinical spectrum of psoriasis.

Clinical Characteristics of Patients with Pustular Psoriasis: A Single-Center Retrospective Observational Study

Clinical and epidemiologic data on pustular psoriasis are scarce. To investigate the phenotypes of pustular psoriasis and the patients’ characteristics observed in a real-life retrospective observational study. The number of incident cases of pustular psoriasis registered in the period 2005–2021 was retrieved from the electronic medical records of the University Hospital of Verona. One hundred and forty cases of pustular psoriasis were collected. Ninety-one out of 140 patients (65%) were females, with a median (IQR) age of 57 (43–66) years. According to the ERASPEN classification criteria, 116 patients (83%) had palmoplantar pustulosis (PPP), 13 (9%) generalized pustular psoriasis (GPP), and 11 (8%) acrodermatitis continua of Hallopeau (ACH). Gender distribution and median age were consistent among the three groups. The prevalence of psoriatic arthritis in GPP, ACH, and PPP was 8%, 36%, and 28%, respectively. During the same period, a total of 4718 cases of plaque psoriasis were retrieved, with a 1:34 ratio of pustular over plaque psoriasis. Pustular psoriasis is much rarer than plaque psoriasis, with PPP being the more common subtype.

Palmoplantar pustulosis and acrodermatitis continua of Hallopeau: demographical and clinical comparative study in a large multicentre cohort

Background

Acral pustular disease within the pustular psoriasis/psoriasis‐like spectrum mainly includes palmoplantar pustulosis (PPP) and acrodermatitis continua of Hallopeau (ACH). Scarce data argue for a distinction between these two entities, but no study has compared the clinical and epidemiologic characteristics of ACH and PPP.

Objectives

We aimed to perform a comparative description of the epidemiological and clinical characteristics of PPP and ACH in a multicentre retrospective cohort.

Methods

In this multicentre national retrospective cohort study, we compared the epidemiological characteristics, comorbidities and psoriasis characteristics of patients with PPP and ACH.

Results

A total of 234 patients were included: 203 (87%) with PPP, 18 (8%) with ACH and 13 (6%) with both, according to 2017 ERASPEN criteria. As compared with ACH, PPP was associated with female sex, smoking activity and higher median BMI (P = 0.01, P = 0.02 and P = 0.05 respectively). A family background of psoriasis was more frequent in PPP than ACH. Age of onset of palmoplantar disease was similar between PPP and ACH patients, median age 44 and 48 years respectively. Peripheral joint inflammatory involvement was the only rheumatic disease associated with ACH. The association with another psoriasis type was similar in PPP and ACH (57.6% and 61.1% respectively).

Conclusion

Our study confirms in a large PPP cohort the predominance of females and a high prevalence of smoking and elevated body mass index but also shows an association of these features in PPP as compared with ACH. In addition, it highlights peripheral arthritis as the only arthritis endotype associated with ACH. Increased knowledge of the immunogenetic backgrounds underlying these two entities is warranted to better stratify pustular psoriasis or psoriasis‐like entities for precision medicine.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Epidemiology and clinical features of pustular psoriasis: A 15-year retrospective cohort

Pustular psoriasis (PuP) is a rare variant of psoriasis with a unique immunopathogenesis, unlike its more prevalent plaque-type counterpart. However, data available are limited due to its low prevalence. This study aimed to describe the demographic profile, precipitating factors, clinical presentations, and treatments among patients with different PuP subtypes from a 15-year retrospective cohort study in Thailand. A total of 60 patients were included in this study. There was female predominance (73.3%) and mean age of onset was 38.1 ± 17.6 years. Generalized PuP (GPP) was the most prevalent subtype (80.0%), followed by acrodermatitis continua of Hallopeau (13.3%) and palmoplantar pustulosis (6.7%). Precipitating factors included corticosteroid withdrawal, upper respiratory tract infection, and pregnancy. One-third of PuP occurred concomitantly with other psoriasis variants, especially the plaque type. The most prescribed systemic and topical treatments were oral acitretin (60.0%) and topical corticosteroids (98.3%), respectively. Only two patients were treated with narrow-band ultraviolet B. In conclusion, four out of every five PuP patients in this center had GPP. Corticosteroid withdrawal, upper respiratory tract infection, and pregnancy are important precipitating factors. Coexistence with other psoriasis variants was identified in one out of every three patients. Acitretin remains the mainstay of systemic treatment.

Biologics in the treatment of pustular psoriasis

INTRODUCTION

Pustular psoriasis is a group of skin diseases characterized by neutrophil infiltration in the epidermis and formation of sterile pustules. Conventional treatments, such as retinoids and immunosuppressive drugs, have improved the clinical manifestations; however, many patients suffer from drug-related toxicity or are resistant to therapy.

AREAS COVERED

In this review, the authors focus on the efficacy and safety of these biologics, including anti-IL-1β (gevokizumab and canakinumab), anti-IL-1 R (anakinra), anti-IL-36 R (BI 655130), anti-tumor necrosis factor-α (etanercept, infliximab, and adalimumab), anti-IL-12/23 (ustekinumab), anti-IL-17A (secukinumab and ixekizumab), anti-IL-17RA (brodalumab), anti-IL-2 R (basiliximab), anti-IL-6 R (tocilizumab), and anti-IL-23 (risankizumab and guselkumab), for treating pustular psoriasis.

EXPERT OPINION

Patients with pustular psoriasis treated with biologics demonstrated positive responses. Anti-TNF-α is the most available biologics for the treatment of pustular psoriasis, and anti-IL-12/23 and anti-IL-17A might be considered as the first- or second-line therapy for moderate-to-severe and refractory pustular psoriasis. Anti-IL-17A can be used in the pustular psoriasis patients who failed to respond to anti-TNF agents and anti-IL-12/23. Therapeutic efficacy of biologics in pustular psoriasis might have no association with IL-36 RN mutation status.

Acrodermatitis continua of Hallopeau: clinical perspectives

Acrodermatitis continua of Hallopeau (ACH) is a rare, sterile pustular eruption of one or more digits. The condition presents with tender pustules and underlying erythema on the tip of a digit, more frequently arising on a finger than a toe. As far as classification, ACH is considered a localized form of pustular psoriasis. The eruption typically occurs after local trauma or infection, but such a history is not always present and various other etiologies have been described including infectious, neural, inflammatory, and genetic causes. The natural progression of ACH is chronic and progressive, often resulting in irreversible complications such as onychodystrophy that can result in anonychia, as well as osteitis that can result in osteolysis of the distal phalanges. Because of the rarity of ACH, there have been no randomized controlled studies to evaluate therapies, resulting in an absence of standardized treatment guidelines. In clinical practice, a wide variety of treatments have been attempted, with outcomes ranging from recalcitrance to complete resolution. In recent years, the introduction of biologics has provided a new class of therapy that has revolutionized the treatment of ACH. Specifically, rapid and sustained responses have been reported with the use of anti-tumor necrosis factor agents like infliximab, adalimumab, and etanercept; IL-17 inhibitors like secukinumab; IL-12/23 inhibitors like ustekinumab; and IL-1 inhibitors like anakinra. Nevertheless, there remains a considerable need for more research into treatment for the benefit of individual patients with ACH as well as for the clinical knowledge gained by such efforts. The purpose of this review is to provide a comprehensive overview of the key features of ACH as well as a discussion of clinical management strategies for this unique and debilitating condition.

Outcomes of various types of therapy in patients with treatment-resistant acrodermatitis continua of Hallopeau

Background: Chronic acrodermatitis continua of Hallopeau (ACH) is a rare form of pustular psoriasis predominantly affecting the distal phalanges of the fingers and toes. The disease manifests by pustular rash with marked infiltration, fissures, and often results into severe dystrophy of nail plates. ACH is refractory to most of psoriasis standard of care (SOC) therapies.

Objective: The objective of this study is to assess the prospects of secukinumab therapy of ACH based on current clinical observation.

Methods: We observed a female patient with ACH. Number of SOC treatments were applied in that case including local PUVA therapy, systemic retinoids, methotrexate, and biologic agents.

Result: Secukinumab, a IL-17 inhibitor, demonstrated pronounced clinical effect in the case of ACH refractory to other SOC therapies.

Conclusion: IL-17 inhibition provided by secukinumab was linked to clinically meaningful improvement in the heavily pretreated ACH. Further exploration and clinical studies may be important to provide more data on secukinumab effects in ACH.

Biologic therapy for acrodermatitis continua of Hallopeau: Successful treatment with secukinumab and review of the literature

Acrodermatitis continua of Hallopeau (ACH) is a rare pustular psoriasis variant refractory to many conventional treatments. We report the successful treatment with secukinumab of a patient with a long history of ACH with marked onychodystrophy with frank pustulosis on the nail bed and with accompanying arthritis. Blockade of the IL-17 receptor A has shown promise in the treatment of psoriatic erythroderma and generalized pustular psoriasis not responsive to conventional treatment. A rapid response was observed in our patient, in both skin lesions and arthritic symptoms, underlining the ability of secukinumab to improve symptoms beyond those of plaque psoriasis.

The Use of Biologic Therapy in the Treatment of Acrodermatitis Continua of Hallopeau: A Review

Acrodermatitis continua of Hallopeau is a rare subtype of pustular psoriasis that presents as a sterile, pustular eruption commonly in the finger tips and toes. This disease inflicts both the skin and nail bed, and causes severe disfigurement of the distal phalanges. Because it is a variant of pustular psoriasis, acrodermatitis continua of Hallopeau is commonly managed with antipsoriatic medications. Common approaches to treatment include topical therapy (corticosteroids, vitamin D analogs, and calcineurin inhibitors), systemic therapy, and in more severe cases, biologic therapy. This review will discuss how acrodermatitis continua of Hallopeau is diagnosed and how it is managed, with a particular emphasis on the use of biologics.

Clinical and genetic differences between pustular psoriasis subtypes

Background

The term pustular psoriasis indicates a group of severe skin disorders characterized by eruptions of neutrophil-filled pustules. The disease, which often manifests with concurrent psoriasis vulgaris, can have an acute systemic (generalized pustular psoriasis [GPP]) or chronic localized (palmoplantar pustulosis [PPP] and acrodermatitis continua of Hallopeau [ACH]) presentation. Although mutations have been uncovered in IL36RN and AP1S3, the rarity of the disease has hindered the study of genotype-phenotype correlations.

Objective

We sought to characterize the clinical and genetic features of pustular psoriasis through the analysis of an extended patient cohort.

Methods

We ascertained a data set of unprecedented size, including 863 unrelated patients (251 with GPP, 560 with PPP, 28 with ACH, and 24 with multiple diagnoses). We undertook mutation screening in 473 cases.

Results

Psoriasis vulgaris concurrence was lowest in PPP (15.8% vs 54.4% in GPP and 46.2% in ACH, P < .0005 for both), whereas the mean age of onset was earliest in GPP (31.0 vs 43.7 years in PPP and 51.8 years in ACH, P < .0001 for both). The percentage of female patients was greater in PPP (77.0%) than in GPP (62.5%; P = 5.8 × 10⁻⁵). The same applied to the prevalence of smokers (79.8% vs 28.3%, P < 10⁻¹⁵). Although AP1S3 alleles had similar frequency (0.03-0.05) across disease subtypes, IL36RN mutations were less common in patients with PPP (0.03) than in those with GPP (0.19) and ACH (0.16; P = 1.9 × 10⁻¹⁴ and .002, respectively). Importantly, IL36RN disease alleles had a dose-dependent effect on age of onset in all forms of pustular psoriasis (P = .003).

Conclusions

The analysis of an unparalleled resource revealed key clinical and genetic differences between patients with PPP and those with GPP.

Pustular psoriasis: pathophysiology and current treatment perspectives

Psoriasis vulgaris is a chronic inflammatory disease that classically affects skin and joints and is associated with numerous comorbidities. There are several clinical subtypes of psoriasis including the uncommon pustular variants, which are subdivided into generalized and localized forms. Generalized forms of pustular psoriasis include acute generalized pustular psoriasis, pustular psoriasis of pregnancy, and infantile and juvenile pustular psoriasis. Localized forms include acrodermatitis continua of Hallopeau and palmoplantar pustular psoriasis. These subtypes vary in their presentations, but all have similar histopathologic characteristics. The immunopathogenesis of each entity remains to be fully elucidated and some debate exists as to whether these inflammatory pustular dermatoses should be classified as entities distinct from psoriasis vulgaris. Due to the rarity of these conditions and the questionable link to the common, plaque-type psoriasis, numerous therapies have shown variable results and most entities remain difficult to treat. With increasing knowledge of the pathogenesis of these variants of pustular psoriasis, the development and use of biologic and other immunomodulatory therapies holds promise for the future of successfully treating pustular variants of psoriasis.

Case of acrodermatitis continua of Hallopeau following psoriasis with atypical clinical presentation

We present a 63-year-old Japanese woman who had clinically unique symmetrical skin rashes on her lower face, inframammary area, back and extremities, with some pustules on the cheeks. Skin biopsy specimens showed typical findings of psoriasis, and Psoriasis Area and Severity Index score was 5.9. After the skin lesions were treated successfully with vitamin D3 ointment, pustules developed on the tips of the fingers and toes, with paronychial and subungual involvement. The pathology of the nail matrix was consistent with pustular psoriasis, and the patient was diagnosed with acrodermatitis continua of Hallopeau (ACH) following psoriasis with an unusual clinical presentation. ACH was well controlled with a low dose of cyclosporin. Our patient is a rare case chronologically affected by two diseases in the same category. We confirmed that ACH is a variant of pustular psoriasis, and believe that the patient could provide another clue to determining the entity of ACH.