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.

Update on subcutaneous methotrexate for inflammatory arthritis and psoriasis Gino Antonio Vena,1,2 Nicoletta Cassano,1,2 Florenzo Iannone3 1Dermatology and Venereology Private Practice, Bari, 2Dermatology and Venereology Private Practice, Barletta, 3Department of Emergency and Organ Transplantation, Rheumatology Unit, University of Bari, Bari, Italy Methotrexate (MTX) is one of the mainstays of treatment for several immune-mediated inflammatory joint and skin diseases, especially rheumatoid arthritis (RA) and moderate-to-severe psoriasis. Oral MTX has been used for the treatment of such diseases for decades for many reasons. There is, however, a relevant interpatient variability of clinical and safety outcomes that can also be related to differences in patients’ individual pharmacogenomic profile. Orally administered MTX has been found to have a saturable intestinal absorption and nonlinear pharmacokinetics, with significant consequences on drug bioavailability and clinical efficacy. The current evidence shows that parenterally administered MTX results in rapid and complete absorption, higher serum levels, and less variable exposure than oral dosing. The use of parenteral MTX, particularly when administered as a subcutaneous (SC) injection, has recently raised great interest in order to overcome the limitations of oral MTX. The effectiveness and safety of SC MTX have mostly been assessed in rheumatological settings, especially in patients with RA. There are only a limited number of data on SC MTX in juvenile idiopathic arthritis and even fewer in psoriatic disease. Various clinical experiences have suggested that SC MTX is more effective than oral MTX and may provide significant benefit even in patients in whom oral MTX proved to be inadequate. The increased efficacy of SC MTX resulting from higher drug exposure compared with oral MTX has been associated with a similar safety profile and in various reports even with a lower frequency of gastrointestinal complaints. The aim of this article was to review the available literature data on SC MTX treatment of inflammatory arthritis, with special emphasis on RA and psoriasis, examining differences with oral MTX treatment. A brief mention of pharmacokinetics, pharmacodynamic features and pharmacoeconomic considerations is also given. Keywords: subcutaneous methotrexate, efficacy, tolerability, juvenile idiopathic arthritis, rheumatoid arthritis, psoriatic disease

The available information about the effects of pregnancy on psoriasis and those of psoriasis on pregnancy is almost limited, despite the high frequency of the disease in the general population, as well as in women in reproductive years. Considering the existing evidence, pregnancy does not tend to have a negative influence on psoriasis, as in most women who experience a change in the severity and course of their psoriasis during pregnancy, the change is more likely to be reported as an improvement. This assumption can be applied more convincingly to plaque-type psoriasis, while an exception may be represented by generalized pustular psoriasis, which has been somehow linked to impetigo herpetiformis. Conflicting findings emerged from the few available studies that explored the effect of psoriasis on pregnancy outcomes. Recent studies found an association between moderate-to-severe psoriasis and some pregnancy complications, including pregnancy-induced hypertensive diseases, and have emphasized a trend toward a newborn with low birth weight in patients with psoriasis, especially in those suffering from severe forms. The safety profile during pregnancy is not completely known for many drugs used to treat psoriasis. Moisturizers and low- to moderate-potency topical steroids or ultraviolet B phototherapy represent the first-line therapy for pregnant patients. Many dermatologists may, however, recommend discontinuing all drugs during pregnancy, in consideration of medico-legal issues, and also taking into account that common forms of psoriasis do not compromise the maternal and fetal health. Anyway, for those women whose psoriasis improves during pregnancy, the interruption of any therapy for psoriasis can be a reasonable strategy. The objective of this paper was to review the most relevant literature data on psoriasis in pregnancy, trying to give concurrently practical information about clinical and prognostic aspects, as well as counseling and management.

Emerging data have strengthened the importance of substance P (SP) as a proinflammatory mediator in human pathology. A role for SP in the pathogenesis of urticaria has long been hypothesized. Literature data regarding the possible role of SP in chronic urticaria/chronic spontaneous urticaria (CSU) have been reviewed and summarized in this manuscript. This review is based on pertinent articles that were retrieved by a selective literature search in the PubMed database. Articles in English published up to July 2018 were taken into consideration. Recent studies in patients with CSU have demonstrated that circulating levels of SP are significantly elevated, in correlation with disease severity, and that SP-positive basophils are upregulated. SP has been shown to trigger degranulation in basophils derived from CSU patients. Moreover, SP can be involved in pseudoallergic reactions and may act as a histamine-releasing factor in a subset of patients with CSU. Current evidence suggests that the biological activity of SP can be exerted not only through the conventional NK-1 receptor but also through the recently identified Mas-related G protein-coupled receptors. MRGPRX2 can cause mast cell activation and has been found to be upregulated in the skin of patients with severe chronic urticaria. Many findings seem to support the pathogenic involvement of SP in chronic urticaria/CSU. However, further studies are necessary to elucidate the role of SP as a mediator in CSU pathogenesis and a potential new therapeutic target.

The coexistence of psoriasis with autoimmune bullous diseases (AIBDs), particularly bullous pemphigoid (BP), has been documented in case reports and series, as well as in epidemiological studies. The onset of psoriasis precedes that of BP in the majority of cases. Patients with concomitant BP and psoriasis are generally younger at the onset of BP and present with fewer erosions and blisters as compared with patients suffering from isolated BP. Intriguingly, it has been speculated that some BP cases with comorbid psoriasis can actually correspond to anti-laminin gamma-1 pemphigoid, a rare form that was recently recognized as a distinct entity and which can mimic BP and/or other subepidermal AIBDs. The pathomechanisms underlying the BP–psoriasis association have not yet been identified, although several hypotheses have been proposed. The most credited among such hypotheses involves the so-called “epitope spreading” phenomenon, with tissue injury secondary to a primary inflammatory process (i.e., psoriasis) leading to the exposure of sequestered antigens evoking a secondary autoimmune disease (i.e., bullous pemphigoid). This narrative review aims to give a brief overview of the association between psoriasis and BP, examining epidemiological, clinical, and immunopathological features, the pathomechanisms underlying this association, the treatments for psoriasis incriminated as potential triggers of BP, and the therapeutic management of patients with psoriasis and BP.

Metabolic syndrome (MS) is a cluster of risk factors for cardiovascular disease and is considered a chronic low-level systemic inflammatory condition. Recent preliminary findings have shown an increased prevalence of MS among patients with chronic urticaria (CU) as compared to controls, with a particularly higher prevalence detected in patients with uncontrolled CU. Chronic spontaneous urticaria (CSU) appears to share some pathomechanisms with MS, including a pro-inflammatory state, increased oxidative stress, alterations in adipokine profile and activation of the coagulation system. Further studies are needed to assess the association of MS and its components with CU/CSU and to obtain more precise information regarding epidemiological aspects, clinical significance and implications. The aim of this review is to present the most relevant literature data on the link between CU/CSU and MS.