Nail involvement associated with palmoplantar pustulosis

Drugs and the skin: A concise review of cutaneous adverse drug reactions

Drug-induced skin disease or cutaneous adverse drug reactions (CADRs) are terms that encompass the clinical manifestations of the skin, mucosae and adnexa induced by a drug or its metabolites. The skin is the organ most frequently affected by drug reactions, which may affect up to 10% of hospitalized patients and occur in 1-3% of multimedicated patients. Most CADRs are mild or self-resolving conditions; however, 2-6.7% of could develop into potentially life-threatening conditions. CADRs represent a heterogeneous field and can be diagnostically challenging as they may potentially mimic any dermatosis. Currently, there are between 29-35 different cutaneous drug-reaction patterns reported ranging from mild dermatitis to an extensively burnt patient. The most frequently reported are maculopapular rash, urticaria/angioedema, fixed drug eruption and erythema multiforme. Less common but more severe patterns include erythroderma, drug reaction with eosinophilia and systemic symptoms, and Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum. Almost any drug can induce a CADR, but antibiotics, nonsteroidal anti-inflammatory drugs and antiepileptics are the most frequently involved. Different mechanisms are involved in the pathogenesis of CADRs, although in some cases, these remain still unknown. CADRs could be classified in different ways: (i) type A (augmented) or type B (bizarre); (ii) immediate or delayed; (iii) immune-mediated or nonimmune-mediated; (iv) nonsevere or life-threatening; and (v) by their phenotype, including exanthematous, urticarial, pustular and blistering morphology. Recognizing a specific CADR will mostly depend on the ability of the physician to perform a detailed clinical examination, the proper description of the morphology of the skin lesions and supporting laboratory and/or skin biopsy findings.

Autoinflammatory Keratinization Diseases-The Concept, Pathophysiology, and Clinical Implications

Recent advances in medical genetics elucidated the background of diseases characterized by superficial dermal and epidermal inflammation with resultant aberrant keratosis. This led to introducing the term autoinflammatory keratinization diseases encompassing entities in which monogenic mutations cause spontaneous activation of the innate immunity and subsequent disruption of the keratinization process. Originally, autoinflammatory keratinization diseases were attributed to pathogenic variants of CARD14 (generalized pustular psoriasis with concomitant psoriasis vulgaris, palmoplantar pustulosis, type V pityriasis rubra pilaris), IL36RN (generalized pustular psoriasis without concomitant psoriasis vulgaris, impetigo herpetiformis, acrodermatitis continua of Hallopeau), NLRP1 (familial forms of keratosis lichenoides chronica), and genes of the mevalonate pathway, i.e., MVK, PMVK, MVD, and FDPS (porokeratosis). Since then, endotypes underlying novel entities matching the concept of autoinflammatory keratinization diseases have been discovered (mutations of JAK1, POMP, and EGFR). This review describes the concept and pathophysiology of autoinflammatory keratinization diseases and outlines the characteristic clinical features of the associated entities. Furthermore, a novel term for NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) describing the spectrum of autoinflammatory keratinization diseases secondary to NLRP1 mutations is proposed.

Pustular psoriasis in Malaysia: A review of the Malaysian Psoriasis Registry 2007-2018

Pustular psoriasis (PP) is an uncommon subtype of psoriasis with distinct genetic features and clinical phenotypes. Patients with PP tend to experience frequent flares and significant morbidity. This study aims to determine the clinical characteristics, co-morbidities and treatment of PP patients in Malaysia. This was a cross-sectional study of patients with PP notified to the Malaysian Psoriasis Registry (MPR) between January 2007 and December 2018. Of 21 735 psoriasis patients, 148 (0.7%) had pustular psoriasis. Of these, 93 (62.8%) were diagnosed with generalized pustular psoriasis (GPP) and 55 (37.2%) with localized PP (LPP). The mean age for pustular psoriasis onset was 31.71 ± 18.33 years with a male to female ratio of 1:2.1. Patients with PP were more likely to have dyslipidaemia (23.6% vs. 16.5%, p = 0.022), severe disease (Body surface area >10 and/or Dermatology Life Quality Index [DLQI] >10) (64.8% vs. 50%, p = 0.003) and require systemic therapy (51.4% vs. 13.9%, p < 0.001) compared to non-PP patients. Patients with PP also suffered greater impairment to their quality of life (DLQI >10, 48.9% vs. 40.3%, p = 0.046), had more days off school/work (2.06 ± 6.09 vs. 0.5 ± 4.91, p = 0.004) and a higher mean number of hospitalizations (0.31 ± 0.95 vs. 0.05 ± 1.22, p = 0.001) in 6 months compared to non-PP patients. Overall, 0.7% of psoriasis patients in the MPR had pustular psoriasis. Patients with PP had a higher rate of dyslipidaemia, severe disease, greater impairment of quality of life and systemic therapy usage compared to other psoriasis subtypes.

Guselkumab for the Treatment of Palmoplantar Pustulosis: A Japanese Perspective

Palmoplantar pustulosis (PPP) is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles. PPP is refractory to various therapies such as topical ointment, oral medicine, and phototherapies. Pustulotic arthro-osteitis (PAO) is a major comorbidity of PPP that severely impairs patients’ quality of life. Recently, guselkumab, a monoclonal antibody against IL-23, has been available for the treatment of PPP in Japan. The purpose of the present review is to describe the characteristics of Japanese PPP patients and biologic therapy of PPP/PAO using guselkumab. Most Japanese dermatologists consider PPP as a distinct entity and co-existence of PPP and psoriasis is rare. However, outside Japan, PPP is often considered to be palmoplantar psoriasis, and extra-palmoplantar lesions associated with PPP are regarded as psoriasis. PPP develops or exacerbates either with or without arthralgia, following focal infections, such as tonsillitis, odontogenic infection, and sinusitis. Treatment of focal infection results in dramatic effects on cutaneous lesions as well as joint pain. By contrast, we sometimes see patients whose skin/joint symptoms do not improve after treatment of focal infection, whose focus of infection cannot be identified even in a detailed examination, and/or who refuse tonsillectomy even if strongly recommended. Such cases are considered to be indications of biologics. In this review, clinical features, pathophysiology and guselkumab therapy are discussed.

Similarity and difference between palmoplantar pustulosis and pustular psoriasis

Palmoplantar pustulosis is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles. Palmoplantar pustulosis has many similar aspects to psoriasis, either plaque and pustular type, namely familial occurrence between palmoplantar pustulosis and psoriasis, the appearance of the Köbner phenomenon, joint involvement, and nail involvement. Pustular psoriasis is classified into generalized and localized types, and there are a number of papers regarding palmoplantar pustulosis as an acral variant of localized pustular psoriasis. Many Japanese dermatologists consider palmoplantar pustulosis to be a distinct entity from pustular psoriasis, and the coexistence of palmoplantar pustulosis and psoriasis is rare. However, outside Japan, palmoplantar pustulosis is often considered to be palmoplantar psoriasis or palmoplantar pustular psoriasis, and extra-palmoplantar lesions are also considered to be psoriasis. The purpose of the current review is to compare the similarities and differences between palmoplantar pustulosis and generalized/localized pustular psoriasis. Japanese patients with palmoplantar pustulosis have a close relationship with focal infection, and the associated bone-joint manifestation exclusively involves the anterior chest wall. Furthermore, pediatric occurrence of palmoplantar pustulosis is extremely rare, and difference of genetic background between palmoplantar pustulosis and psoriasis has also been reported. Treatment of focal infection often results in dramatic effects on both cutaneous lesions and joint pain of palmoplantar pustulosis. Those findings suggest that palmoplantar pustulosis should be separately considered from either palmoplantar psoriasis or palmoplantar pustular psoriasis. The clinicopathological features and therapeutic approach of both diseases are discussed.

Simultaneous occurrence of Pyoderma Gangrenosum and Palmoplantar Pustular Psoriasis: Is it an association or coincidental findings?

Pyoderma Gangrenosum and Palmoplantar Pustular Psoriasis share the common pathogenesis, histological features, age group, and female preponderance that suggests a common etiological link.

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.

Microscopic Examination of Nail Clippings from Patients with Palmoplantar Pustulosis

This study describes the clinical characteristics and microscopic findings of nails from 25 patients with palmoplantar pustulosis.

Methods

This is a cross-sectional study of adult patients with clear-cut palmoplantar pustulosis. Onychodystrophy severity was evaluated in fingernails using the nail psoriasis severity index (NAPSI). A fragment of the most dystrophic fingernail was collected from each patient and submitted to routine histotechnical processing. The following microscopic parameters were evaluated: nail plate and subungual region thickness, presence or absence of parakeratosis, number of layers of parakeratosis, and presence of neutrophils, serous lakes, bacteria, blood, and fungi.

Results

Twenty-one patients (84%) presented onychodystrophy with a mean NAPSI score of 12.67. The most common nail change was pitting (76.19% of patients). On average, nail plate thickness and subungual region thickness measured 0.42 and 0.14 mm, respectively. Neutrophils and fungi were not observed, but serous lakes were found in 4.7%, bacteria in 28.57%, blood in 4.76%, and parakeratosis in 19.05% of the patients.

Conclusions

although palmoplantar pustulosis is a disease with great amounts of neutrophils in the epidermis, those cells were not found in the nail clippings studied herein. Furthermore, when clinical aspects and microscopic findings of palmoplantar pustulosis are compared to those of similar studies in psoriasis vulgaris, they show different characteristics.