Pathophysiology of generalized pustular psoriasis

Case report: Successful treatment of acute generalized pustular psoriasis with multiple comorbidities with oral tacrolimus

Acute generalized pustular psoriasis (GPP) is a serious illness. Despite various treatment methods, there is still lack of effective treatment plans for refractory cases with multiple comorbidities. This case report presents a 67-year-old woman with acute GPP, stage 4 chronic kidney disease (CKD), type 2 diabetes, and cardiovascular disease, in whom skin symptom disappearance and kidney function improvement were observed after the use of oral tacrolimus as the sole therapy. This is the first report on the application of tacrolimus in the treatment of acute GPP, especially refractory acute GPP. The successful treatment indicates that there are shared immune pathways between acute GPP and CKD, and the pathways can be interdicted by tacrolimus. Further studies are needed to optimize the therapy to maximize efficacy and minimize toxicity.

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.

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.

Serum procalcitonin and C-reactive protein in the evaluation of bacterial infection in generalized pustular psoriasis

Background

There is an obvious need for more prompt and specific biomarkers of bacterial infections in generalized pustular psoriasis patients.

Objective

The aim of this study was to evaluate the diagnostic properties and define appropriate cut-off values of procalcitonin and C-reactive protein in predicting bacterial infection in generalized pustular psoriasis patients.

Methods

Sixty-four generalized pustular psoriasis patients hospitalized from June 2014 to May 2017 were included in this retrospective study. The values of procalcitonin, C-reactive protein, details of infection, and other clinical parameters were analyzed.

Results

Receiver operating characteristic curve analysis generated similar areas (p = 0.051) under the curve for procalcitonin 0.896 (95% CI 0.782–1.000) and C-reactive protein 0.748 (95% CI 0.613–0.883). A cut-off value of 1.50 ng/mL for procalcitonin and 46.75 mg/dL for C-reactive protein gave the best combination of sensitivity (75.0% for procalcitonin, 91.7% for C-reactive protein) and specificity (100% for procalcitonin, 53.8% for C-reactive protein). Procalcitonin was significantly positively correlated with C-reactive protein levels both in the infected (r = 0.843, p = 0.040) and non-infected group (r = 0.799, p = 0.000).

Study limitations

The sample size and the retrospective design are limitations.

Conclusions

The serum levels of procalcitonin and C-reactive protein performed equally well to differentiate bacterial infection from non-infection in generalized pustular psoriasis patients. The reference value of procalcitonin and C-reactive protein applied to predicting bacterial infection in most clinical cases may not be suitable for generalized pustular psoriasis patients. C-reactive protein had better diagnostic sensitivity than procalcitonin; however, the specificity of procalcitonin was superior to that of C-reactive protein.

Generalized pustular psoriasis induced by systemic steroid dose reduction

Generalized pustular psoriasis, or psoriasis of von Zumbusch, is an acute and severe clinical form of psoriasis, which usually occurs in patients with psoriasis undergoing aggravating factors. In this work, we report the case of a female patient, 70 years old, who developed generalized pustular psoriasis symptoms while reducing the dose of oral corticosteroids, improperly introduced for the treatment of alleged acute generalized exanthematous pustulosis. The differential diagnosis of generalized pustular psoriasis should be made with other pustular dermatoses, such as subcorneal pustulosis, IgA pemphigus and especially with acute generalized exanthematous pustulosis. Personal history of psoriasis and histopathological findings with psoriasiform changes and subcorneal pustule favored the diagnosis. She was treated with acitretin 30 mg / day, progressing to complete regression of the lesions.

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.

Correlation of IL36RN mutation with different clinical features of pustular psoriasis in Chinese patients

Different studies have reported various values for the percentage of patients with IL36RN mutations, and it has also been reported that the sites of these mutations differ among different ethnicities. The current study was a cross-sectional study conducted to investigate the risk factors predicting IL36RN mutation in Chinese patients with different clinical features of pustular psoriasis. 57 Han Chinese patients, including 32 with generalized pustular psoriasis, 14 with palmoplantar pustulosis, 9 with plaque-type psoriasis with pustules, and 2 with erythrodermic psoriasis, were enrolled between March 2013 and July 2014. Blood samples were collected, genomic DNA was extracted from leukocytes, and polymerase chain reaction (PCR)-based Sanger sequencing was used to analyze the coding exons and flanking introns of the IL36RN gene. The patients with generalized pustular psoriasis exhibited the highest IL36RN mutation rate (75 %) among the aforementioned patient types, with the subgroup consisting of those patients who had features of acrodermatitis continua of Hallopeau exhibiting the highest c.115+6T>C mutation rate (93.8 %). In addition, early onset, ever generalized pustular psoriasis (more than two attacks), ever acrodermatitis continua of Hallopeau, inverse psoriasis, and a family history of pustular psoriasis were associated with IL36RN mutation. The c.115+6T>C mutation was the most common and the most important variant in all subtypes of pustular psoriasis with IL36RN mutations among our sample of Chinese patients.

Characteristics of fever, etiologic factors, antibiotic use and prognosis in febrile dermatology inpatients

BACKGROUND

Generally, fever is observed in >30% of hospitalized patients. However, little is known about fever in dermatology inpatients.

OBJECTIVES

The aim of this study was to investigate and document the incidence, characteristics, and etiologic factors of fever in febrile dermatology inpatients and to describe the practice of antibiotic use and prognosis in the same group.

METHODS

The medical records for 928 inpatients were retrospectively analyzed.

RESULTS

The incidence of fever was found to be 16.2%. Mean length of hospital stay was found to be longer in febrile patients. Of the 176 febrile episodes, 79 (44.9%) occurred in patients without infections, 43 (24.4%) in patients with community-acquired infections, 25 (14.2%) in patients with healthcare-associated infections, 18 (10.2%) in patients classified with fever of non-infectious/infectious causes, and 11 (6.3%) in a group for whom the etiologic factors of fever were undetermined. Antibiotic treatment was started in 36.2% of febrile inpatients. The overall mortality rate was 0.6%.

CONCLUSIONS

This is the first study to investigate febrile episodes in dermatology inpatients. Fever is a frequently encountered symptom in dermatology inpatients. Febrile episodes resulted from mostly non-infectious entities, mainly consisting of inflammatory dermatologic disorders. Antibiotics were ordered in a higher percentage of patients in the febrile group. Dermatologists started prophylactic or empiric antibiotic therapy in febrile patients with non-infectious or inflammatory diagnoses on the assumption that these patients had an increased risk for infection as a result of impaired skin integrity and use of immunosuppressive drug therapy. The overall mortality rate was very low in the study group of dermatology inpatients.

Interleukin-36-receptor antagonist deficiency and generalized pustular psoriasis

BACKGROUND

Generalized pustular psoriasis is a life-threatening disease of unknown cause. It is characterized by sudden, repeated episodes of high-grade fever, generalized rash, and disseminated pustules, with hyperleukocytosis and elevated serum levels of C-reactive protein, which may be associated with plaque-type psoriasis.

METHODS

We performed homozygosity mapping and direct sequencing in nine Tunisian multiplex families with autosomal recessive generalized pustular psoriasis. We assessed the effect of mutations on protein expression and conformation, stability, and function.

RESULTS

We identified significant linkage to an interval of 1.2 megabases on chromosome 2q13-q14.1 and a homozygous missense mutation in IL36RN, encoding an interleukin-36-receptor antagonist (interleukin-36Ra), an antiinflammatory cytokine. This mutation predicts the substitution of a proline residue for leucine at amino acid position 27 (L27P). Homology-based structural modeling of human interleukin-36Ra suggests that the proline at position 27 affects both the stability of interleukin-36Ra and its interaction with its receptor, interleukin-1 receptor-like 2 (interleukin-1 receptor-related protein 2). Biochemical analyses showed that the L27P variant was poorly expressed and less potent than the nonvariant interleukin-36Ra in inhibiting a cytokine-induced response in an interleukin-8 reporter assay, leading to enhanced production of inflammatory cytokines (interleukin-8 in particular) by keratinocytes from the patients.

CONCLUSIONS

Aberrant interleukin-36Ra structure and function lead to unregulated secretion of inflammatory cytokines and generalized pustular psoriasis. (Funded by Agence Nationale de la Recherche and Société Française de Dermatologie.).

Clinical and laboratory features in acute generalized pustular psoriasis: a retrospective study of 34 patients

BACKGROUND

Acute generalized pustular psoriasis (AGPP) is a rare variant of psoriasis that can be lethal without proper treatment. It can be caused by the withdrawal of corticosteroids and, among its extra-cutaneous manifestations, liver abnormalities are frequently under-reported or attributed to drugs.

OBJECTIVE

The aim of this study was to assess the clinical and laboratory data, treatment options, and disease outcome in patients with AGPP and to search for significant differences between subgroups of these patients.

STUDY DESIGN

This was a retrospective analysis of the clinical files from inpatients with AGPP observed in our department between 1973 and 2008. Statistical tests were performed at a significance level of 5%.

SETTING

This was an inpatient, single-center study.

MAIN OUTCOME MEASURES

Outcome measures were a previous history of psoriasis, corticosteroid use before admittance, mortality rate, white blood cell count, absolute neutrophil count, and abnormalities in liver enzymes.

RESULTS

A total of 34 patients fulfilled the inclusion criteria, of whom 61% were men and 65% had a previous history of psoriasis vulgaris. Topical corticosteroids were applied by 50% of patients before admittance. Skin lesions remitted with methotrexate, etretinate, or acitretin treatment in all but two patients who died of sepsis. Abnormalities in liver enzymes were present in 47% of patients. Patients without a previous history of psoriasis had a significantly younger age at the first episode of AGPP. In the comparison between the groups of patients with and without liver abnormalities, a male preponderance and higher leukocyte counts were found in the former, with a positive correlation between the absolute neutrophil count and total bilirubin also being observed. Previous use of retinoids or methotrexate was not associated with these hepatic alterations.

LIMITATIONS

Limitations of the data were that this was a single-center, retrospective study with a small sample size.

CONCLUSIONS

Withdrawal of systemic or topical corticosteroids can precipitate or worsen AGPP and these agents should not be used in these patients. Liver abnormalities can be considered an extra-cutaneous manifestation of AGPP. As in other series, no association between the use of drugs and changes in liver tests was found and therefore the deleterious withdrawal of efficient drugs, namely acitretin and methotrexate, should be avoided.

Generalized pustular psoriasis in childhood

Generalized pustular psoriasis is a rare form of psoriasis consisting of a generalized eruption of sudden onset with erythema and sterile pustules. In children, generalized pustular psoriasis is even more uncommon and may present as a severe and potentially life-threatening disorder. In this study, we present demographics, clinical aspects, treatment response, and follow-up of seven children with generalized pustular psoriasis. Retrospective study reviewing the records of seven children with generalized pustular psoriasis including age, gender, age of onset, presence of scalp and nail involvement, family history, concomitant diseases, precipitating factors, treatment modalities, and outcome. Age of first symptoms ranged from 1 month to 11 years. All patients received systemic retinoids at one time of the follow-up period. Other treatment modalities included immunosuppressive drugs, biologics, phototherapy, and sulfasalazine. Two patients presented with severe constitutional illness, secondary infection and septic shock, including one fatal outcome. All further cases have remained free of recurrences for a mean period of up to 3 years. In our study, generalized pustular psoriasis presented a wide clinical spectrum in children ranging from mild, asymptomatic outbreaks to more severe, life-threatening episodes. One fatality was observed. Children generally responded well to systemic retinoids. Further studies and long-term follow-up periods are needed to define potential trigger factors, efficacy and safety of different treatment modalities in children with generalized pustular psoriasis.

Psoriasis: the epidermal component

Besides the infiltrate of immune cells in psoriatic lesions, the principal characteristic changes in the skin are changes of the epidermal architecture and alterations of keratinocyte differentiation, which are distinct from other inflammatory skin diseases clinically and histologically. Several lines of evidence suggest that 3 of the 9 psoriasis susceptibility loci identified today might play a role in the keratinocyte differentiation program. Therefore, besides the dysregulation of the immune system, intrinsic epidermal components are also likely to play a role in triggering and/or sustaining the disease process and contribute to the chronicity of psoriasis and its frequent relapses.