Deciphering the Complex Immunopathogenesis of Alopecia Areata.

Alopecia areata (AA) is an autoimmune-mediated disorder in which the proximal hair follicle (HF) attack results in non-scarring partial to total scalp or body hair loss. Despite the growing knowledge about AA, its exact cause still needs to be understood. However, immunity and genetic factors are affirmed to be critical in AA development. While the genome-wide association studies proved the innate and acquired immunity involvement, AA mouse models implicated the IFN-γ- and cytotoxic CD8+ T-cell-mediated immune response as the main drivers of disease pathogenesis. The AA hair loss is caused by T-cell-mediated inflammation in the HF area, disturbing its function and disrupting the hair growth cycle without destroying the follicle. Thus, the loss of HF immune privilege, autoimmune HF destruction mediated by cytotoxic mechanisms, and the upregulation of inflammatory pathways play a crucial role. AA is associated with concurrent systemic and autoimmune disorders such as atopic dermatitis, vitiligo, psoriasis, and thyroiditis. Likewise, the patient's quality of life (QoL) is significantly impaired by morphologic disfigurement caused by the illness. The patients experience a negative impact on psychological well-being and self-esteem and may be more likely to suffer from psychiatric comorbidities. This manuscript aims to present the latest knowledge on the pathogenesis of AA, which involves genetic, epigenetic, immunological, and environmental factors, with a particular emphasis on immunopathogenesis.

Comprehensive Insight into Lichen Planus Immunopathogenesis.

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Current Concepts of Vitiligo Immunopathogenesis.

Vitiligo is an acquired immune-mediated disorder of pigmentation clinically characterized by well-defined depigmented or chalk-white macules and patches on the skin. The prevalence of vitiligo varies by geographical area, affecting 0.5% to 2% of the population. The disease imposes a significant psychological burden due to its major impact on patients' social and emotional aspects of life. Given its autoimmune background, vitiligo is frequently associated with other autoimmune diseases or immune-mediated diseases. Vitiligo is a multifaceted disorder that involves both genetic predisposition and environmental triggers. In recent years, major predisposing genetic loci for the development of vitiligo have been discovered. The current findings emphasize the critical role of immune cells and their mediators in the immunopathogenesis of vitiligo. Oxidative-stress-mediated activation of innate immunity cells such as dendritic cells, natural killer, and ILC-1 cells is thought to be a key event in the early onset of vitiligo. Innate immunity cells serve as a bridge to adaptive immunity cells including T helper 1 cells, cytotoxic T cells and resident memory T cells. IFN-γ is the primary cytokine mediator that activates the JAK/STAT pathway, causing keratinocytes to produce the key chemokines CXCL9 and CXCL10. Complex interactions between immune and non-immune cells finally result in apoptosis of melanocytes. This paper summarizes current knowledge on the etiological and genetic factors that contribute to vitiligo, with a focus on immunopathogenesis and the key cellular and cytokine players in the disease's inflammatory pathways.

Current Concepts of Psoriasis Immunopathogenesis.

Psoriasis is a recurrent, chronic, immune-mediated, systemic inflammatory disease of the skin, joints, and other organic systems. After atopic dermatitis, chronic stationary psoriasis is the most common inflammatory skin disease, affecting an average of 2-4% of the world's population. The disease carries a significant burden due to its numerous comorbidities and the major impact on patients' social and emotional aspects of life. According to current knowledge, psoriasis is a multifactorial disease that occurs in genetically predisposed individuals under various environmental factors, which trigger an immune response disorder with a series of complex inflammatory cascades. The disease is initiated and maintained by mutual interaction of the innate and adaptive immune cells, primarily dendritic cells, T lymphocytes, and keratinocytes, whose leading role alternates at different stages of the disease, consisting mainly in the IL-23/Th17 pathway. Inflammatory events result in consequent epidermal and dermal changes and evolution of the characteristic psoriatic phenotype, respectively. This paper aims to present a comprehensive overview of current knowledge on psoriasis genetic and environmental etiological factors, immunopathogenesis, and the leading cellular and cytokine participants in the inflammatory pathways of this disease.

The possible involvement of granulysin mediated cytotoxicity in keratinocytes disruption in lichen planus.

Lichen planus is a chronic mucocutanous disorder histopathologically characterized with a keratinocytes apoptosis, subsequent basal cell layer liquefaction and accumulation of the inflammatory infiltrate in papillary dermis. A formation of apoptotic bodies in basal cell layer is due to a cytotoxic lymphocyte attack to the basal keratinocytes. It has been demonstrated that the cytotoxic molecules included in this attack are perforin and granzyme B. Both molecules are found upregulated in CD8+ lymphocytes that are in close contact to keratinocytes. However, their amount is lower in lichen planus than in other skin disease characterized by liquefaction and vacuolar degeneration of the basal epidermal layer. This could speculate about other cytotoxic molecule such as granulysin that could mediate keratinocyte apoptosis. Therefore, in this article we hypothesize about the crucial role of granulysin molecule in keratinocytes killing that could contribute to a lichen planus pathogenesis.

Biologic and Targeted Therapy in the Treatment of Psoriasis - A Retrospective Study from a National Referral Center.

Psoriasis is one of the most common chronic inflammatory skin disorders worldwide with a significant number of patients suffering from moderate to severe disease and requiring systemic therapy. Over the past two decades, better knowledge of disease pathophysiology has translated into treatment advances for both primary disease and its associated comorbidities. However, it is important to review the use of biologic or targeted therapy in a clinical setting in order to understand how to optimize therapeutic results and recognize any unmet needs in this patient subpopulation. We conducted a retrospective study on a cohort of patients diagnosed with psoriasis that had received at least one dose of biologic or targeted therapy for the treatment of psoriasis at the Rijeka Clinical Hospital Center. By documenting treatment trends and specific patient characteristics, we will be able to address any unmet needs in this patient population and provide individualized care strategies.

Tumor Necrosis Factor Antagonists in the Treatment of Pyoderma Gangrenosum, Acne, and Suppurative Hidradenitis (PASH) Syndrome.

The clinical triad of pyoderma gangrenosum (PG), acne and suppurative hidradenitis (HS) has been described under the acronym PASH syndrome and is considered to represent a distinct entity in the group of autoinflammatory diseases. It is a fairly new, only recently recognized disorder with a limited number of reported cases and without defined treatment recommendations. We aimed to summarize currently available data on the use of tumor necrosis factor (TNF) antagonists in the management of PASH syndrome and report on our own experience with the use of adalimumab in a patient presenting with this specific constellation of clinical signs and symptoms. Among the 11 cases identified in the literature, infliximab and adalimumab were the most commonly used agents, both exhibiting favorable effects in the majority of, but not all, patients. This was particularly evident in terms of relatively rapid remission of PG whereas HS lesions seemed to be more resistant to treatment. In our patient, adalimumab monotherapy resulted in a remarkable and sustained remission, although significant improvement of HS lesions was observed only from week 16 of therapy onwards. In summary, TNF antagonists are a promising treatment for PASH; however, conclusions regarding the choice of a specific agent, optimal dosing or use in combination with other treatment modalities cannot yet be drawn.

Satisfaction with life and coping skills in the acute and chronic urticaria.

BACKGROUND: The purpose of this study was to examine the differences in satisfaction with life and coping strategies between patients with acute and chronic urticaria. SUBJECTS AND METHODS: Sixty patients with urticaria were divided into 2 groups after 6 weeks of standardized dermatology treatment (33 patients with acute and 27 patients with chronic urticaria). At baseline, all patients answered the following questionnaires: Satisfaction with Life Scale (SWLS), Personal Wellbeing Index (PWI-A), The Multidimensional Coping Inventory (COPE) and General questionnaire (age, gender, education, employment, marital status). After six weeks all the participants were re-tested with 2 questionnaires: SWLS and PWI-A. RESULTS: Six weeks after the initial testing there was a statistically significant difference in satisfaction with life between patients with acute and chronic urticaria. Patients with acute urticaria were more satisfied with their lives than patients with chronic urticaria. Also, there was a statistically significant difference in the use of emotion-focused coping, seeking social support for emotional reasons and seeking social support for instrumental reasons. Patients with acute urticaria used emotion-focused coping and sought social support for emotional and instrumental reasons to a greater degree than patients with chronic urticaria. CONCLUSION: Patients with acute urticaria were more satisfied with their lives than patients with chronic urticaria. Patients with acute urticaria used emotion-focused coping and sought social support for emotional and instrumental reasons to a greater degree than patients with chronic urticaria.

Cytotoxic T lymphocytes as a potential brake of keratinocyte proliferation in psoriasis.

Psoriasis is a chronic papulosquamous skin disease, histologically characterized by epidermal hyperproliferation and dermal infiltration of inflammatory cells. The majority of T lymphocytes infiltrating dermis are CD4+ T lymphocytes secreting type 1 and type 17 cytokines. These cytokines are responsible for triggering keratinocyte proliferation as well as chemokine secretion and subsequent migration of other inflammatory cells in the skin. Contrarily, lymphocytes that accumulate in epidermis are mainly CD8+ T lymphocytes. According to the recent findings, these cells can also secrete type 1 and type 17 cytokines. However, it is demonstrated so far that epidermal CD8+ T lymphocytes contain higher amounts of cytolytic molecules, such as perforin, granzyme B and granulysin whose role in psoriasis pathogenesis is still unknown. Therefore, in this article we hypothesize the active involvement of cell mediated cytotoxicity in killing the proliferating keratinocytes as a mechanism of potential self-defense and possible brake in psoriatic plaque formation, maintaining skin homeostasis.

Dermatophyte Infections in Primorsko-Goranska County, Croatia: a 21-year Survey.

This study examined the frequency of dermatophytoses in the Primorsko-Goranska County, a north-western part of Croatia, over a period of 21 years (1988-2008). All fungal samples were microscopically examined with 20% potassium hydroxide (KOH) solution. Fungal infections were confirmed in 26.9% cases. Out of these, dermatophytes were isolated in 38.3%, Candida spp. infection in 55.1% cases, while non-dermatophyte molds were identified in 6.6% isolates. The most frequently isolated dermatophyte was Trichophyton (T.) mentagrophytes var. interdigitalis (55.4%), followed by Mycrosporum (M.) canis (36.9%), T. violaceum (3.2%), M. gypseum (2.2%), and T. verrucosum (1.3%). Epidermophyton (E.) floccosum (0.9%) and T. rubrum (0.1%) were identified only sporadically. The most common dermatophytosis diagnosed in the 21-year period was tinea pedis (26.2%) followed by tinea capitis (21.8%) and tinea corporis (20.1%). Toenail onychomycosis (14.5%) was more common than fingernail onychomycosis (2.0%). T. mentagrophytes var. interdigitalis was the major pathogen causing tinea pedis (86.6%) as well as toenail onychomycosis (93.9%), while M. canis was most frequently isolated in tinea capitis (98.6%), tinea corporis (62.1%), and tinea faciei (40.2%). With regard to age and sex, T. mentagrophytes var. interdigitalis infections were predominant in middle-aged men. M. canis affected mostly children up to 9 years with a slight predominance in girls. Data from epidemiological trend analysis such as presented in our study are important for evidence-based public health measures for the prevention and control of dermatophytoses.

[Guidelines for the diagnosis and treatment of psoriasis]. / Smjernice za dijagnostiku i lijecenje vulgarne psorijaze.

Croatian dermatovenerological society of the Croatian Medical Association formed the working group which consists of leading experts for psoriasis in Croatia. After a critical analysis of relevant scientific papers, the working group has developed guidelines for the diagnosis and treatment of psoriasis.

Adverse reactions and alleged allergy to local anesthetics: analysis of 331 patients.

The aim of this study was to determine the prevalence of true local anesthetic (LA) allergy among patients referred for suspected hypersensitivity and to describe the main characteristics of adverse drug reactions (ADR) induced by LA in our population. We retrospectively analyzed the medical files of patients referred to the Department of Dermatovenereology, University Hospital Center Rijeka, Rijeka, Croatia, for the investigation of LA hypersensitivity in the period between January 2000 and December 2012. A total of 331 patients underwent skin testing and, in cases of negative results, subcutaneous exposition to LA. In patients with suspected delayed reaction, patch test was performed. Altogether, 331 patients reported 419 independent ADR occurring during 346 procedures. Most commonly, patients reported having only one ADR, but 41 (12.4%) of them had two reactions, 14 (4.2%) had three, five (1.5%) had four and in one patient (0.3%) five ADR to LA were observed. The majority of reactions occurred during dental procedures when most commonly lidocaine and articaine were used. Local reactions were reported in 44 patients, whereas 490 general symptoms occurred during 375 independent ADR in 287 patients. The most common symptoms were cardiovascular system reactions in 89 patients (18.2%). Allergic reaction was detected in three patients (0.91%). One patient showed immediate-type reaction to bupivacaine and two patients had a delayed-type reaction to lidocaine. Adverse reactions to LA are common and are mostly due to their pharmacological properties and drug combinations or psychogenic origin. Allergic accidents to LA are rare.

Expression of TWEAK in normal human skin, dermatitis and epidermal neoplasms: association with proliferation and differentiation of keratinocytes.

BACKGROUND: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) has been implicated in the pathogenesis of various inflammatory pathologies and cancer. We aimed to investigate its expression in normal human skin, inflammatory skin diseases and epidermal neoplasms. METHODS: Immunohistochemistry for TWEAK was performed in samples of healthy skin, plaque psoriasis, lichen planus, prurigo nodularis, discoid lupus erythematosus, lichen sclerosus, seborrheic keratosis, common warts, actinic keratosis, Bowen's disease, keratoacanthoma and basal and squamous cell carcinoma. Double immunofluorescence was used to investigate co-localization of TWEAK with cytokeratin-10 and proliferating cell nuclear antigen (PCNA). RESULTS: TWEAK was robustly expressed in the epidermis of healthy skin and decreased in inflammatory conditions, both in the context of epidermal hyperplasia and atrophy. Decreased TWEAK immunoreactivity was regularly observed in common warts, actinic keratosis and Bowen's disease, particularly in areas of marked proliferation as evidenced by PCNA-positive nuclei. In squamous cell carcinoma, expression of TWEAK ranged from strong to completely absent, and it mostly corresponded with the expression of cytokeratin-10. TWEAK was absent in keratoacanthoma and basal cell carcinoma. CONCLUSIONS: TWEAK is a constitutively expressed epidermal protein whose downregulation might be an early indicator of disturbed differentiation or pathologic proliferation of keratinocytes that accompany inflammatory and neoplastic skin diseases.

Increased expression of TRAIL and its death receptors DR4 and DR5 in plaque psoriasis.

TNF-related apoptosis-inducing ligand (TRAIL) is recognized as an important regulator of immune responses during infections and various autoimmune-mediated pathologies. Its role in inflammatory dermatoses is largely unknown. We aimed to investigate the expression of TRAIL and its receptors DR4 and DR5 in psoriasis vulgaris. Immunohistochemistry for TRAIL, DR4 and DR5 was performed on samples of lesional (n = 10) and non-lesional (n = 10) skin of patients with plaque psoriasis and skin of healthy volunteers (n = 10). Expression of TRAIL and its receptors was further examined by means of double immunofluorescence staining and co-localization with CD4, CD8, CD11c, CD68, CD16 and CD56 markers. Immunohistochemical staining for TRAIL was significantly enhanced in psoriatic lesional as well as non-lesional epidermis compared to the epidermis of healthy skin. Lesional epidermis also showed increased immunoreactivity for DR5. In addition, expression of TRAIL and both of its receptors was significantly increased in the dermis of lesional skin. As evidenced by double immunofluorescence, TRAIL was readily expressed by most of the examined cells of the inflammatory infiltrate in psoriatic lesions. In contrast, the expression of DR4 was found mostly among CD4+ and CD8+ cells but was only nuclear, while DR5 showed cytoplasmic staining in rare CD16+, CD56+ and CD68+ cells. According to abundant in situ presence of TRAIL and its receptors in lesional psoriatic skin, it seems that this cytokine participates in the complex interplay between keratinocytes and cells of the dermal infiltrate and thus contributes to the inflammatory cycle in psoriasis vulgaris.

Childhood and adulthood traumatic experiences in patients with psoriasis.

It is well known that several psychiatric disorders may be related to childhood psychological trauma. Recent studies have associated childhood exposure to trauma to some skin diseases. Our study aimed at exploring whether psoriasis is related to the reported positive and negative traumatic life events in different age intervals beginning from early childhood to adulthood. Furthermore, we investigated differences between psoriatics with early and late onset according to traumatic experiences in different age intervals. Also, we investigated the possible correlation of traumatic experiences with the disease severity. One hundred patients with psoriasis and 101 controls (patients with skin conditions considered to be "non-psychosomatic") were enrolled in the study. All participants completed a specific questionnaire measuring traumatic life experiences (Traumatic Antecedents Questionnaire, TAQ). The TAQ assesses positive personal experiences (competence and safety) and negative personal experiences (neglect, separation, secrets, emotional, physical and sexual abuse, trauma witnessing, other traumas and exposure to alcohol/drugs) from early childhood to adulthood. The severity of psoriasis was estimated according to the Psoriasis Area and Severity Index (PASI), a standardized measuring instrument. The amount of positive experiences did not differ significantly among groups, except for safety scores that were higher in controls compared with both psoriatic groups (early and late onset). On the other side, negative traumatic experiences appeared more frequently in patients with psoriasis during all developmental periods. We found no correlation between severity of psoriasis and traumatic experiences. The present study demonstrates an increased history of childhood and adulthood negative traumatic experiences in patients with psoriasis compared to the control group. Our findings suggest a relationship between retrospectively reported negative traumatic experiences and psoriasis.

[Systemic therapy in the treatment of psoriasis: drugs of prebiological era]. / Sustavna terapija u lijecenju psorijaze: lijekovi predbioloske ere.

Psoriasis is a chronic, recurrent skin disease that lasts a whole life. A quarter of adults are suffering from severe forms of psoriasis that requires the application of the systemic treatment. Despite the development of new groups of medicines, traditional therapy is still of great importance. Methotrexate, cyclosporine and acitretin are cost-effective and provide excellent disease control. Methotrexate and acitretin are good choice in terms of maintenance therapy, whereas cyclosporin would ideally be used as intermittent therapy. Fear of serious side effects of traditional drugs can be avoided by setting individualized plan for each patient and careful monitoring.