Histological differentiation between palmoplantar pustulosis and pompholyx

Immunohistochemical evaluation of keratins and involucrin in differentiating between palmoplantar pustulosis and pompholyx

BACKGROUND

Palmoplantar pustulosis (PPP) and pompholyx are chronic diseases characterized by pustules and vesicles on the palms and soles. These disorders often have similar clinicopathological features, which lead to diagnostic difficulties. We aimed to investigate the expression patterns of keratins and involucrin in PPP and pompholyx using immunohistochemical staining.

METHODS

Skin biopsies from patients with PPP (n = 40) and pompholyx (n = 22) were immunohistochemically analyzed for Keratin 5, 9, 14, and involucrin expression.

RESULTS

K5 expression was higher in PPP than in pompholyx, with diffusely positive expression in the basal, spinous, and granular layers. K14 expression did not differ between groups. K9 expression was observed near the pompholyx vesicle (P = 0.014) and stratum spinosum (P < 0.001) but was almost absent around PPP pustules. Involucrin expression was diffused around the PPP pustules and partially around the pompholyx vesicles, but without statistical significance (P = 0.123). Involucrin expression was elevated in the basal layer of the PPP compared with that in the pompholyx (P = 0.023).

CONCLUSION

PPP and pompholyx exhibited distinctive differentiation in the expression of K5, K9, and involucrin.

A fluorescence imaging technique suggests that sweat leakage in the epidermis contributes to the pathomechanism of palmoplantar pustulosis

Sweat is an essential protection system for the body, but its failure can result in pathologic conditions, including several skin diseases, such as palmoplantar pustulosis (PPP). As reduced intraepidermal E-cadherin expression in skin lesions was confirmed in PPP skin lesions, a role for interleukin (IL)-1-rich sweat in PPP has been proposed, and IL-1 has been implicated in the altered E-cadherin expression observed in both cultured keratinocytes and mice epidermis. For further investigation, live imaging of sweat perspiration on a mouse toe-pad under two-photon excitation microscopy was performed using a novel fluorescent dye cocktail (which we named JSAC). Finally, intraepidermal vesicle formation which is the main cause of PPP pathogenesis was successfully induced using our "LASER-snipe" technique with JSAC. "LASER-snipe" is a type of laser ablation technique that uses two-photon absorption of fluorescent material to destroy a few acrosyringium cells at a pinpoint location in three-dimensional space of living tissue to cause eccrine sweat leakage. These observatory techniques and this mouse model may be useful not only in live imaging for physiological phenomena in vivo such as PPP pathomechanism investigation, but also for the field of functional physiological morphology.

A Case of Eosinophilic Pustular Folliculitis with Vegetating Lesions on the Lower Legs and Feet Resembling Pemphigus Vegetans

Abstract is missing (Short communication)

Recent advances in palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is a chronic inflammatory condition where crops of sterile pustules with erythematous keratotic lesions causing bleeding and pain appear on the palms and soles. Recently, the European Rare and Severe Expert Network considered PPP as a variant of pustular psoriasis with or without psoriasis vulgaris.

The prevalence of PPP varies from 0.050 to 0.12%. PPP occurs more frequently in women and the highest prevalence occurred between the ages of 50 and 69 years. Nail psoriasis seems to be frequent in PPP, ranging from 30 to 76%, and psoriatic arthritis in 8.6 to 26% of PPP patients.

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome and pustulotic arthro-osteitis are considered PPP-associated disorders. PPP has been reported with other co-morbidities such as psychiatric disorders, thyroid-associated disease, altered calcium homeostasis, gluten sensitivity diabetes, obesity, and dyslipidemia, but larger studies are required to prove such associations. Environmental exacerbating factors might contribute to the onset or worsening of PPP such as cigarette smoking, stress, focal infections, metal allergies, and drug intake. Genetic predisposition plays an important role in PPP.

In PPP, both the innate and the adaptive immune systems are activated. The acrosyringeal expression of IL-17 has been demonstrated, indicating that the eccrine sweat gland is an active component of the skin barrier and an immune-competent structure. Increased levels of several inflammatory molecules, including IL-8, IL-1α, IL-1β, IL-17A, IL-17C, IL-17D, IL-17F, IL-22, IL-23A, and IL-23 receptor, have been detected in PPP biopsies. Increased serum levels of TNF-α, IL-17, IL-22, and IFN-γ have been detected in patients with PPP in comparison to healthy subjects, suggesting a similar inflammatory pattern to psoriasis vulgaris. Oral and tonsillar infections serve as trigger factors for PPP.

Long-term therapy is required for many patients, but high-quality data are limited, contributing to uncertainty about the ideal approach to treatment.

So close, and yet so far away: The dichotomy of the specific immune response and inflammation in psoriasis and atopic dermatitis

Characterization of the complex interplay between cytokines, chemokines and microorganisms has led to a better understanding of the pathogenesis of both psoriasis and AD and resulted in new therapeutics targeting distinct immune responses. Psoriasis and AD share many characteristics: they are highly prevalent, chronic, cause primarily skin inflammation, but are associated with comorbidities, and come with a devastating quality of life due to itch and stigmatization. However, the pathogenesis of psoriasis and AD is opposing - psoriasis is dominated by a Th17 immune response that causes neutrophil migration, induction of innate immunity and exaggerated epithelial metabolism. Leading cytokines of this Th17 immune response are IL-17A and F, IL-22 and TNF-a. AD is characterized by Th2 immunity characterized by the signature cytokines IL-4 and IL-13 leading to an impaired epidermal barrier, dampened innate immunity and eosinophil migration. This review compares genetics, microbiome and T-cell infiltrate and resulting epithelial response in psoriasis and AD. Whilst the antagonistic course of psoriasis and AD is confirmed by response to specific biologics targeting the key cytokines of inflammation in psoriasis and AD, respectively, clinically overlapping phenotypes are challenging in our daily clinical practice. We conclude this review by summarizing what is known about these mixed phenotypes and how the identification of clinically relevant endotypes and molecular-driven decision-making is the next step in the field of dermato-immunology.

[Pitfalls in occupational dermatology]

Occupational dermatology has become a vibrant and interesting specialty, particularly in recent years. This includes more than hand eczema (HE). The increasing prevalence of atopic dermatitis (AD) has led to an increase of atopic hand eczema which can be worsened in certain occupations. New systemic therapies have improved the range of treatments for HE. The current guideline on hand eczema includes a variety of topical and systemic therapies. Nevertheless, in daily occupational dermatological practice, there are still chronic cases, especially vesicular hand eczema. They can often not be assigned to a clear cause, which is often a problem for those who are affected. In addition, co-factors such as chronic infectious comorbidities and psychological factors/illnesses must be considered. We present challenges in occupational dermatology by reporting special cases.

Ayurvedic visha hara (antitoxic) chikitsa in recurrent dyshidrotic eczema skin disease: A case report

Dyshidrotic eczema is a chronic, enigmatic condition that usually affects the hands and feet that probably accounts for about 5%–20% of hand eczemas. In Ayurveda various skin manifestation are mentioned under different chapter & context like kushtha, visarpa, kshudra kushtha, vidradi, krimi roga, keeta visha (insect bite), Garavisha & Dooshi visha (latent toxicity).Visphota variety of kushtha is characterized by pustules which are either white or reddish in appearance. These pustules have a thin skin and it is pitta-kapha predominant. The ayurvedic diagnosis was made as “Dushivisha janya visaphota kushtha” and treatment was done basis on this. There was not a single cases on the internet treated on Ayurvedic line of management thus the present article was prepared to assess the role of Visha Hara and Rasayan Chikitsa in such emerging automimmune skin condition. Improvement in the skin lesion were observed after a period of 1 months of regular treatment and complete remission with no further attack after 2-month follow-up. The improvement was observable through the follow-up photograph.

Diagnosis, Screening and Treatment of Patients with Palmoplantar Pustulosis (PPP): A Review of Current Practices and Recommendations

Palmoplantar pustulosis (PPP) is a rare, chronic, recurrent inflammatory disease that affects the palms and/or the soles with sterile, erupting pustules, which are debilitating and usually resistant to treatment. It has genetic, histopathologic and clinical features that are not present in psoriasis; thus, it can be classified as a variant of psoriasis or as a separate entity. Smoking and upper respiratory infections have been suggested as main triggers of PPP. PPP is a challenging disease to manage, and the treatment approach involves both topical and systemic therapies, as well as phototherapy and targeted molecules. No gold standard therapy has yet been identified, and none of the treatments are curative. In patients with mild disease, control may be achieved with on-demand occlusion of topical agents. In patients with moderate-to-severe PPP, phototherapy or a classical systemic agent (acitretin being the best treatment option, especially in combination with PUVA) may be effective. Refractory patients or those with contraindications to use these therapies may be good candidates for apremilast or biologic therapy, particularly anti-IL-17A and anti-IL-23 agents. Recent PPP trials are focusing on blockage of IL-36 or IL-1 pathways, which play an important role in innate immunity. Indeed, IL-36 isoforms have been strongly implicated in the pathogenesis of psoriasis. Therefore, blockage of the IL-36 pathway has become a new treatment target in PPP, and three studies are currently evaluating the use of monoclonal antibodies that block the IL-36 receptor in PPP: ANB019 and spesolimab (BI 655130). In this review, we explore the diagnosis, screening and treatment of patients with PPP.

Palmoplantar Pustulosis: Recent Advances in Etiopathogenesis and Emerging Treatments

Palmoplantar pustulosis (PPP) is a chronic, recurrent skin disease belonging to the spectrum of psoriasis. It is characterized by an eruption of sterile pustules on the palms and soles. Recent studies in PPP have focused on genetic differences between pustular phenotypes and the role of the innate immunological system and the microbiome in the etiopathogenesis of the disease. Mutations in IL36RN (a major predisposing factor for generalized pustular psoriasis) were found in selected patients with PPP and were associated with earlier disease onset. Studies have shown that the interleukin (IL)-17 and IL-36 pathways might be involved in the pathogenesis of PPP. A microbiome has been demonstrated in the vesicopustules of PPP, and an abundance of Staphylococcus appears to be increased by smoking. Improved understanding of the underlying etiopathogenesis of PPP has led to advances in treatment options, and targeted therapies for PPP have been evaluated or are under evaluation against more than 12 molecules in ongoing clinical trials. These targets include CXCR2 (IL-8 receptor type B), granulocyte colony-stimulating factor receptor, IL-1 receptor, IL-8, IL-12, IL-23, IL-17A, IL-17 receptor, IL-36 receptor, phosphodiesterase-4, and tumor necrosis factor-α.

Efficacy and Safety of Oral Alitretinoin in Hand Eczema and Palmoplantar Pustulosis in Korean Patients

Background

Previous studies have demonstrated efficacy and safety of oral alitretinoin in hand eczema (HE) whereas in palmoplantar pustulosis (PPP), which can be difficult to distinguish from HE, efficacy of alitretinoin is still controversial.

Objective

This study aimed to investigate the efficacy and safety of oral alitretinoin in HE and PPP and factors that affect the response of these disorders to alitretinoin.

Methods

We retrospectively analyzed Korean adult patients with moderate-to-severe HE and PPP treated with oral alitretinoin, 46 patients for efficacy assessment and 55 patients for safety assessment.

Results

Among 46 patients who were treated with alitretinoin for at least 1 month, 29 patients (61.1% in HE and 40.0% in PPP) showed response to alitretinoin in the median 14 weeks after treatment. Hyperkeratotic HE showed higher response rate than either vesicular HE or PPP (p=0.026 and p=0.026, respectively). However, PPP with hyperkeratotic features showed as much response as hyperkeratotic HE (p=0.554). When responders and non-responders in total patients were compared, morphology, not diagnosis or initial severity, was the only significantly different factor between the two groups. After alitretinoin discontinuation in responders, relapse rate was 63.6% (7/11) and median time to relapse was 150 days (range, 76~730 days). Adverse events occurred in 47.3% (26/55); however, there were no serious adverse events.

Conclusion

In HE or PPP, lesions with hyperkeratotic morphology can be predicted to respond well to alitretinoin regardless of diagnosis.

Molecular diagnostics of inflammatory disease: New tools and perspectives

This essay reviews current approaches to establish novel molecular diagnostic tools for inflammatory skin diseases. Moreover, it highlights the importance of stratifying patients according to molecular signatures and revising current outdated disease classification systems to eventually reach the goal of personalized medicine.

What do we know about palmoplantar pustulosis?

Palmoplantar pustulosis is characterized by a chronic eruption of sterile pustules on palms and soles. The disease affects mainly women in the sixth and seventh decade of life. Some authors consider palmoplantar pustulosis a separate entity, whereas others consider it a condition in the spectrum of psoriasis. Aim of this study was to summarize the most recent data about PPP which aimed at establishing the nosological position of palmoplantar pustulosis. A systematic search of published literature was carried out. General characteristics of patients with PPP in different populations were present. We reviewed histological, immunological and genetic studies, as well as treatment options for PPP. PPP presents with clinical features, which are not present in psoriasis; however, the common coexistence of psoriasis vulgaris and/or positive family history for psoriasis indicates at least a close relationship between PPP and psoriasis. At present, there are not sufficient data to exclude PPP from psoriasis group.

A comparison of inflammatory mediator expression between palmoplantar pustulosis and pompholyx

BACKGROUND

Both palmoplantar pustulosis (PPP) and pompholyx are clinically characterized by acute eruptions of vesicles or pustules on the palms or soles.

OBJECTIVES

This study aims to compare the expression of certain inflammatory mediator genes and proteins between patients with PPP and pompholyx using skin tissue samples.

METHODS

Skin biopsies obtained from lesional skin from patients with PPP (n = 7) and pompholyx (n = 5) were analysed by quantitative RT-PCR to measure the mRNA levels of nine genes, including IL-4, IL-8, IL-9, IL-17, IL-22, IFN-γ, CCL-20, granzyme and perforin. For immunohistochemical analysis, 34 paraffin-embedded skin specimens (PPP, n = 22; pompholyx, n = 12) were stained with anti-IL-8, IL-17A, IL-22 and granzyme B antibodies.

RESULTS

Of genes analysed, IL-8 and IL-17A mRNA expression levels were significantly higher in the PPP group than the pompholyx group (P = 0.012 in both), whereas the mRNA expression of granzyme B was significantly higher in pompholyx when compared with PPP (P = 0.004). Regarding the IL-17A immunohistochemical staining, tissue from the PPP lesions contained significantly more IL-17A(+) cells in both the epidermis and papillary dermis when compared with pompholyx (P < 0.001 and P = 0.019 respectively). Moreover, the intensity of the IL-8 immunoreactivity was also greater in the PPP skin lesions than the pompholyx tissue (P < 0.001).

CONCLUSIONS

IL-8 and IL-17A, both are increased in PPP tissue, may represent important immunologic mediators that help to differentiate this clinical entity from pompholyx. This study may provide useful clues in distinguishing PPP from pompholyx, as well as helping to understand the pathogeneses of these two diseases.