New insight into mechanisms of pruritus from molecular studies on familial primary localized cutaneous amyloidosis

Lichen Amyloidosis in an Atopic Patient Treated with Dupilumab: A New Therapeutic Option

Lichen amyloidosis (LA) is a type of cutaneous amyloidosis characterized by brownish hyperkeratotic and itchy papules on the lower leg, back, forearm, or thigh. It is associated with itching and atopic dermatitis (AD) according to an etiopathogenetic mechanism that has not yet been fully elucidated. Currently, the available therapies for this condition include oral antihistamines, laser, cyclosporine, topical corticosteroids, and phototherapy, but, in light of the overlap with AD, Dupilumab may also be indicated. We report the case of a female, 52 years old, who had been suffering from AD and LA for about 27 years. She had lesions attributable to both diseases on the trunk and lower limbs associated with severe itching and had proved resistant to cyclosporine therapy. It was decided to opt for Dupilumab with the induction of 2 fl of 300 mg and maintenance with 1 fl every other week. The therapy proved to be effective, returning a total resolution of both diseases one year after the beginning of the treatment. Dupilumab demonstrated efficacy and safety in the LA related to AD and led to clinical and quality of life improvements in this patient. Therefore, Dupilumab should be considered when treating LA. Further studies should be conducted focusing on the efficacy of the drug on LA (whether or not related to AD), changes in the skin lesions after discontinuation, and the safety of long-term application.

Efficacy of topical gabapentin in women with primary macular amyloidosis: A side-by-side triple-blinded randomized clinical trial

BACKGROUND

Primary cutaneous macular amyloidosis (PCMA) is a chronic pruritic cutaneous disease characterized by heterogeneous extracellular deposition of amyloid protein in the skin.

AIMS

This study aimed to evaluate the efficacy of topical 6% gabapentin cream for the treatment of patients with PCMA.

MATERIALS AND METHODS

In this triple-blind clinical trial, a total of 34 patients, who were diagnosed with PCMA, treated using two different strategies of topical gabapentin as the active group and vehicle cream as the control group.

RESULTS

Pruritus score reduction in both groups was statistically significant compared with the baseline value (p < 0.001). There was a significant pigmentation score reduction in intervention group compared with control group after 1 month of the study (p < 0.001). The differences of pigmentation score changes between the groups were not significant at month 2 (p = 0.52) and month 3 (p = 0.22).

CONCLUSIONS

The results of this study suggest that topical gabapentin cream may be effective as a topical agent in the treatment of pruritus associated with PCMA without any significant adverse effects. It is recommended to perform similar studies with a larger sample size and longer duration in both sexes.

Clinical Characteristics of Lichen Amyloidosis Associated with Atopic Dermatitis: A Single Center, Retrospective Study

BACKGROUND

Lichen amyloidosis is a chronic pruritic skin disorder associated with atopic dermatitis, however, the pathogenetic link between these two conditions remains to be elucidated. Only limited research has been performed on patients diagnosed with both pruritic dermatological conditions.

OBJECTIVE

This study aimed to analyze the clinical features of lichen amyloidosis associated with atopic dermatitis.

METHODS

We conducted a matched case-control study of incident lichen amyloidosis with atopic dermatitis between March 2020 and February 2022. Among the 2,481 patients with atopic dermatitis, 20 patients diagnosed with lichen amyloidosis and atopic dermatitis were included as case patients, and 20 patients diagnosed with atopic dermatitis were enrolled as controls. The controls were matched to cases (1:1) by age and sex. We retrospectively reviewed the medical records of the patients.

RESULTS

The prevalence of lichen amyloidosis associated with atopic dermatitis was approximately 0.8%, with a male:female sex ratio of 2.33:1. The recorded onset of lichen amyloidosis associated with atopic dermatitis was more common in adult patients, with moderate-to-severe atopic dermatitis. Lichen amyloidosis lesions in patients with atopic dermatitis were most commonly found on the extremities, sparing the head and neck region. The presence of lichen amyloidosis had no significant impact on severity of atopic dermatitis.

CONCLUSION

In patients with lichen amyloidosis associated with atopic dermatitis, the clinical manifestations of lesions are similar to those of conventional lichen amyloidosis lesions in terms of morphology and regional distribution. Further research is required to elucidate the link between the pathogenesis of these two pruritic dermatological conditions.

Oncostatin M suppresses IL31RA expression in dorsal root ganglia and interleukin-31-induced itching

Background

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by intermittent itchy rash. Type 2 inflammatory cytokines such as interleukin (IL)-4, IL-13, and IL-31 are strongly implicated in AD pathogenesis. Stimulation of IL-31 cognate receptors on C-fiber nerve endings is believed to activate neurons in the dorsal root ganglion (DRG), causing itch. The IL-31 receptor is a heterodimer of OSMRβ and IL31RA subunits, and OSMRβ can also bind oncostatin M (OSM), a pro-inflammatory cytokine released by monocytes/macrophages, dendritic cells, and T lymphocytes. Further, OSM expression is enhanced in the skin lesions of AD and psoriasis vulgaris patients.

Objective

The current study aimed to examine the contributions of OSM to AD pathogenesis and symptom expression.

Methods

The expression levels of the OSM gene (OSM) and various cytokine receptor genes were measured in human patient skin samples, isolated human monocytes, mouse skin samples, and mouse DRG by RT-qPCR. Itching responses to various pruritogens were measured in mice by counting scratching episodes.

Results

We confirmed overexpression of OSM in skin lesions of patients with AD and psoriasis vulgaris. Monocytes isolated from the blood of healthy subjects overexpressed OSM upon stimulation with IL-4 or GM-CSF. Systemic administration of OSM suppressed IL31RA expression in the mouse DRG and IL-31-stimulated scratching behavior. In contrast, systemic administration of OSM increased the expression of IL-4- and IL-13-related receptors in the DRG.

Conclusion

These results suggest that OSM is an important cytokine in the regulation of skin monocytes, promoting the actions of IL-4 and IL-13 in the DRG and suppressing the action of IL-31. It is speculated that OSM released from monocytes in skin modulates the sensitivity of DRG neurons to type 2 inflammatory cytokines and thereby the severity of AD-associated skin itch.

Characterization of Epidermal Function in Individuals with Primary Cutaneous Amyloidosis

Purpose

To compare epidermal biophysical properties, indicators of epidermal function, in individuals with and without primary cutaneous amyloidosis (PCA).

Patients and Methods

This study incorporated 189 patients with PCA and 166 healthy individuals. The GPSkin Barrier was employed to measure transepidermal water loss (TEWL) rates and hydration levels of the stratum corneum. The Sebumeter and the Skin pH Meter were utilized to determine the skin surface's sebum content and pH, respectively. The severity of pruritus in participants was evaluated using the visual analog scale (VAS).

Results

Compared to the control group without PCA, individuals with PCA displayed a notable increase in skin surface pH and TEWL and a decrease in the hydration levels of the stratum corneum (p<0.0001 for all parameters). Additionally, the sebum content was markedly lower in those with PCA than in the controls (p<0.0001). Of particular note, both TEWL and skin surface pH at the lesion sites on the back and the shin were more elevated in lichenoid amyloidosis (LA) and in macular amyloidosis (MA), whereas hydration levels of the stratum corneum and sebum levels were diminished in LA compared to MA (p<0.05). In conclusion, both hydration levels of the stratum corneum and sebum content exhibited an inverse relationship with pruritus severity, whereas TEWL and skin surface pH demonstrated a positive correlation with pruritus intensity.

Conclusion

The function of the epidermis is compromised in individuals diagnosed with PCA. However, the mechanisms underlying these changes await further investigation.

Unusual presentation of transthyretin (ATTR) cardiac amyloidosis: A case report of pruritus as a possible initial symptom and challenging diagnosis

Key Clinical Message

This case emphasizes the significance of cardiac amyloidosis as a potential diagnosis in individuals manifesting with lesion-free pruritus and normal liver tests.

Abstract

Amyloidosis is a complex disorder in which misfolded proteins accumulate in various organs of the body. Cardiac amyloidosis (CA) can lead to heart failure, cardiac arrhythmia, sudden cardiac death, and deposition of proteins in coronary arteries. Diagnosing CA can be difficult, as the cardiac manifestations of amyloidosis can be similar to more prevalent etiologies. In addition, the accumulation of proteins in soft tissues, including the skin, can cause pruritus. In this paper, we present a 70-year-old man with generalized pruritus and no skin lesions, later diagnosed as CA after detecting ascites fluid. This case underscores the importance of considering amyloidosis in patients presenting with nonspecific symptoms, particularly those affecting the skin, and highlights the need for increased awareness of this disease among clinicians.

Successful treatment of lichen amyloidosis coexisting with atopic dermatitis by dupilumab: Four case reports

BACKGROUND

Lichen amyloidosis (LA) is a chronic, severely pruritic skin disease, which is the most common form of primary cutaneous amyloidosis. The treatment of LA has been considered to be difficult. LA may be associated with atopic dermatitis (AD), and in this setting, the treatment options may be more limited. Herein, we report four cases of LA associated with AD successfully treated by dupilumab.

CASE SUMMARY

In this article, we describe four cases of patients who presented with recurrent skin rash accompanied by severe generalized intractable pruritus, diagnosed with refractory LA coexisting with chronic AD. Previous treatments had not produced any apparent improvement. Thus, we administered dupilumab injection subcutaneously at a dose of 600 mg for the first time and 300 mg every 2 wk thereafter. Their lesions all markedly improved.

CONCLUSION

Dupilumab may be a new useful treatment for LA coexisting with AD.

Amyloidosis cutis dyschromica cases caused by GPNMB mutations with different inheritance patterns

BACKGROUND

Amyloidosis cutis dyschromica (ACD) is a rare form of primary cutaneous amyloidosis featured by reticulate dotted hypo- and hyperpigmentation. Recently, loss-of-function mutations in GPNMB, encoding glycoprotein (transmembrane) nonmetastatic melanoma protein B, were found in autosomal-recessive or semi-dominant ACD.

OBJECTIVE

This study aims to detect the genetic defect underlying ACD in nine separate cases and to investigate the functional consequences of the mutants.

METHODS

Nine ACD cases were collected including eight with autosomal-recessive pattern and one with autosomal-dominant pattern. Whole-exome sequencing or Sanger sequencing of the GPNMB gene was performed to detect the pathogenic mutations. Haplotype analysis was employed to determine the origin of mutation c.565C > T using adjacent highly polymorphic SNPs. Immunoblotting and subcellular localization assessments were performed to evaluate the expression of the mutants using HEK293 cells transfected with the GPNMB constructs.

RESULTS

We detected four recurrent mutations (c.393 T > G, p.Y131*; c.565C > T, p.R189*; c.1056delT, p.P353Lfs*20; c.1238 G > C, p.C413S) and two novel mutations (c.935delA, p.N312Tfs*4; c.969 T > A, p.C323*) in GPNMB. Mutation c.565C > T found in six separate ACD cases shared a common haplotype. The two novel mutations caused a decreased abundance of truncated proteins. The c.1238 G > C mutation, which was detected in the autosomal-dominant case, caused abnormal reticular subcellular localization of the protein. A major percentage of wildtype changed its expression pattern when co-expressed with this mutant.

CONCLUSIONS

Our findings proved that the recurrent mutation c.565C > T originated from a founder effect. The autosomal-dominant ACD associated mutation p.C413S played its pathogenic role through a dominant-negative effect on wild-type GPNMB. This study expands the genotype and inherited modes of ACD and improves our understanding of the pathogenesis of this disorder.

Primary Localized Cutaneous Amyloidosis: A Retrospective Study of an Uncommon Skin Disease in the Largest Tertiary Care Center in Switzerland

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is defined by the deposition of amyloid protein in the skin without systemic involvement. There are four subtypes of PLCA: lichen amyloidosis (LA), macular amyloidosis (MA), biphasic amyloidosis (BA), and nodular amyloidosis (NA). PLCA occurs most frequently in Latin Americans and Asians. Treatment is not standardized.

OBJECTIVES

To identify subtypes, demographic and clinical features and treatment efficacy in patients with histopathologically confirmed PLCA.

MATERIALS AND METHODS

Data of PLCA patients were extracted from the electronic hospital database and included if diagnosis of PLCA was histopathologically confirmed and if sufficient information regarding treatment and follow-up was available. The evaluation of the treatment efficacy was based on a novel score to assess the reduction of itch and skin lesions.

RESULTS

In this retrospective, monocentric study, 37 cases of PLCA diagnosed between 2000 and 2020 were included (21 females) with a mean age of 52 years. LA was the most frequent subtype found in 21 patients (56.8%), followed by MA in 10 patients (28%) and BA in 6 patients (16.2%). No cases of NA were included. 22 patients (59.4%) had skin phototype II or III. Regarding treatment, a combination of UVA1 phototherapy with high-potency topical corticosteroids seemed to show the highest efficacy with complete clearance of symptoms in 4 patients (10.8%). A substantial improvement of symptoms was found in 5 patients (12.7%) treated with high-potency topical corticosteroids alone or in combination either with UVA1 or bath PUVA or monotherapy with UVA1 phototherapy or capsaicin (0.075%) cream. Low-/medium-potency topical corticosteroids alone or in combination with UVBnb (311 nm) phototherapy showed a lower efficacy.

CONCLUSION

Our data show that PCLA is a rare disease in central Europe but can also be expected in a predominantly Caucasian population. The best treatment response was achieved with a combination of UVA1 phototherapy and high-potency topical corticosteroids.

Prominent Role of Type 2 Immunity in Skin Diseases-Beyond Atopic Dermatitis

Type 2 immunity, illustrated by T helper 2 lymphocytes (Th2) and downstream cytokines (IL-4, IL-13, IL-31) as well as group 2 innate lymphoid cells (ILC2), is important in host defense and wound healing.¹ The hallmark of type 2 inflammation is eosinophilia and/or high IgE counts and is best recognized in atopic diathesis. Persistent eosinophilia, such as seen in hypereosinophilic syndromes, leads to fibrosis and hence therapeutic Type 2 inhibition in fibrotic diseases is of high interest. Furthermore, as demonstrated in cutaneous T cell lymphoma, advanced disease is characterized by Th1 to Th2 switch allowing cancer progression and immunosuppression. Development of targeted monoclonal antibodies against IL-4Rα (eg, dupilumab) led to a paradigm shift for the treatment of atopic dermatitis (AD) and stimulated research to better understand the role of Type 2 inflammation in other skin conditions. In this review, we summarize up to date knowledge on the role of Type 2 inflammation in skin diseases other than AD and highlight whether the use of Type 2 targeted therapies has been documented or is being investigated in clinical trials. This manuscript reviews the role of Type 2 inflammation in dermatitis, neurodermatitis, IgE-mediated dermatoses (eg, bullous pemphigoid, chronic spontaneous urticaria), sclerodermoid conditions and skin neoplasms.

IL-31, itch and hematological malignancies

Pruritus is one of the most common symptoms experienced by neoplastic patients. The pathogenesis of neoplastic itch is complex and multifactorial and could be due to an unbalanced production of humoral mediators by altered immune effector cells. IL-31 is a pro-inflammatory cytokine produced by CD4 + T helper cells. The aim of this review was to evaluate the role of this Th2 cytokine and its receptor IL-31RA, in the onset of neoplastic pruritus. We analysed scientific literature looking for the most relevant original articles linking IL-31to itch in oncologic diseases. Interleukin-31 seems to be a main itch mediator in several hematologic disease such as Cutaneous T cells lymphomas. In these patients IL-31 was positively linked to itch level, and IL-31 matched with disease stage. IL-31 seems to play an important role in the signalling pathway involved in pruritus, but it is also suggested to play a proinflammatory and immunomodulatory role which could play a part in the progression of the neoplastic disease. Further studies will be fundamental in facing pruritus in oncologic patients, since this problem compromise their quality of life worsening an already critic picture.

Epigenetic editing: Dissecting chromatin function in context

How epigenetic mechanisms regulate genome output and response to stimuli is a fundamental question in development and disease. Past decades have made tremendous progress in deciphering the regulatory relationships involved by correlating aggregated (epi)genomics profiles with global perturbations. However, the recent development of epigenetic editing technologies now enables researchers to move beyond inferred conclusions, towards explicit causal reasoning, through 'programing' precise chromatin perturbations in single cells. Here, we first discuss the major unresolved questions in the epigenetics field that can be addressed by programable epigenome editing, including the context-dependent function and memory of chromatin states. We then describe the epigenetic editing toolkit focusing on CRISPR-based technologies, and highlight its achievements, drawbacks and promise. Finally, we consider the potential future application of epigenetic editing to the study and treatment of specific disease conditions.

Successful treatment of primary cutaneous localized amyloidosis with a combined therapy of ablative fractionated CO2 laser, topical retinoid, corticosteroids and levovitamin C: Five cases with two-year follow-up

Primary cutaneous localized amyloidosis (PCLA) is a pruritic disorder with no radical cure. We trialed a combined therapy of ablative fractionated CO2 laser, topical retinoid, corticosteroids and levovitamin C on five patients. All patients responded with no intolerant signs. Two-year follow-up visit showed no recurrence. This might be a effective method awaiting more samples for further stronger evidence.

Genodermatoses with itch as a prominent feature

A number of inherited conditions cause chronic itch as a part of the recognized phenotype. Advances in the understanding of the genetic factors that cause these diseases elucidate the molecular underpinning of itch as a symptom. Our knowledge of the causes of chronic itch has also advanced, providing an opportunity to integrate the genetic pathophysiology with the molecular landscape of chronic itch mediators. This article reviews select genodermatoses that have itch as a predominant feature with a focus on the pathophysiology of the disease, how it may lead to itch and potential therapeutic targets.

Interleukin-31 and interleukin-31 receptor: New therapeutic targets for atopic dermatitis

Atopic dermatitis (AD) is characterized by chronic, eczematous, severe pruritic skin lesions caused by skin barrier dysfunction and T helper (Th)2 cell-mediated immunity. Interleukin (IL)-31 is a potent pruritogenic cytokine primarily produced by Th2 cells. Both IL-31 transgenic mice and wild-type mice treated with IL-31 exhibit AD-like skin lesions and scratching behaviour. IL-31 receptor α-chain (IL-31RA) is also expressed in peripheral nerves and epidermal keratinocytes, and the roles of IL-31 on pruritus and skin barrier have been investigated. Recently, an anti-IL-31 receptor antibody was shown to significantly improve pruritus in AD patients. This review focuses on IL-31 and IL-31RA in AD.

Clinical and genetic features of Chinese patients with lichen and macular primary localized cutaneous amyloidosis

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is a chronic pruritic skin disorder. The genetic basis of familial (f)PLCA involves mutations in the oncostatin M receptor (OSMR) and interleukin-31 receptor A (IL31RA) genes, but the disease pathophysiology is not fully understood.

AIM

To investigate the OSMR mutation spectrum in patients with sporadic (s)PLCA/fPLCA, lichen/macular PLCA in mainland China.

METHODS

This study was carried out on 64 patients with sPLCA, along with 36 with fPLCA and 10 unaffected individuals collected from 23 unrelated Chinese families. Genomic DNA was extracted from peripheral blood samples. Mutation screening of 17 OSMR exons was performed by Sanger sequencing.

RESULTS

PLCA lesions are typically localized to the shins, forearm and back. Sequence analysis of OSMR exons demonstrated that the OSMR missense mutation rate in patients with fPLCA (63.89%) was significantly higher than that in patients with sPLCA (34.38%). The male/female ratio of patients carrying a homozygous OSMR mutation (0.29) was significantly lower than that of patients carrying a heterozygous OSMR mutation (1.08; P < 0.05) and of patients with wildtype OSMR (1.75; P < 0.01). Age of onset of PLCA with OSMR homozygous mutation (median age 20 years) was earlier than that of PLCA with OSMR heterozygous mutation (median age 32 years; P < 0.01) or PLCA with wildtype genotype (median age 32 years; P < 0.01).

CONCLUSION

The present data indicate OSMR mutations as not only the main cause of fPLCA, but also the potential source of the pathogenesis of sPLCA, although the exact molecular mechanism remains unknown.

Primary Localized Cutaneous Amyloidosis: A Systematic Treatment Review

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is characterized by extracellular deposition of heterogenic amyloid proteins in the skin without systemic involvement. Lichen amyloidosis, macular amyloidosis, and (primary localized cutaneous) nodular amyloidosis are different subtypes of PLCA.

OBJECTIVE

The aim of this study was to review the current reported treatment options for PLCA.

METHODS

This systematic review was based on a search in the PubMed database for English and German articles from 1985 to 2016.

RESULTS

Reports on the treatment of PLCA were limited predominantly to case reports or small case series. There were a few clinical trials but these lacked control groups. A variety of treatment options for PLCA were reported including retinoids, corticosteroids, cyclophosphamide, cyclosporine, amitriptyline, colchicine, cepharanthin, tacrolimus, dimethyl sulfoxide, vitamin D₃ analogs, capsaicin, menthol, hydrocolloid dressings, surgical modalities, laser treatment, and phototherapy.

CONCLUSION

No definitive recommendation of preferable treatment procedures can be made based on the analyzed literature. Randomized controlled trials are needed to offer patients an evidence-based therapy with high-quality standardized treatment regimens for PLCA.

Comparative proteomics analysis of primary cutaneous amyloidosis

Primary cutaneous amyloidosis (PCA) is a localized skin disorder that is characterized by the abnormal deposition of amyloid in the extracellular matrix (ECM) of the dermis. The pathogenesis of PCA is poorly understood. The objective of the present study was to survey proteome changes in PCA lesions in order to gain insight into the molecular basis and pathogenesis of PCA. Total protein from PCA lesions and normal skin tissue samples were extracted and analyzed using the isobaric tags for relative and absolute quantitation technique. The function of differentially expressed proteins in PCA were analyzed by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction analysis. The proteins that were most upregulated in PCA lesions were further analyzed by immunohistochemistry. A total of 1,032 proteins were identified in PCA lesions and control skin samples, with 51 proteins differentially expressed in PCA lesions, of which 27 were upregulated. In PCA lesions, the upregulated proteins were primarily extracellulary located. In addition, GO analysis indicated that the upregulated proteins were significantly enriched in the biological processes of epidermal development, collagen fiber organization and response to wounding (adjusted P<0.001). KEGG analysis indicated that the upregulated proteins were significantly enriched in the signaling pathways of cell communication, ECM receptor interaction and focal adhesion (adjusted P<0.001). Furthermore, the upregulated proteins were enriched in the molecular function of calcium ion binding, and the calcium binding proteins calmodulin-like protein 5, S100 calcium-binding protein A7 (S100A7)/fatty-acid binding protein and S100A8/A9 exhibited the highest levels of upregulation in PCA. This analysis of differentially expressed proteins in PCA suggests that increased focal adhesion, differentiation and wound healing is associated with the pathogenesis of PCA.

Multiple Endocrine Neoplasia: A Genetically Diverse Group of Familial Tumor Syndromes

Multiple endocrine neoplasia (MEN) syndrome is a familial cancer syndrome characterized by neuroendocrine tumors. The syndrome encompasses four major subtypes: MEN1, MEN2A, MEN2B, and MEN4. MEN1 is caused by mutations in the MEN1 gene, MEN2A and MEN2B are caused by mutations in RET, and MEN4 is caused by mutations in CDKNB1. All are inherited in an autosomal dominant pattern, but de novo cases do arise. While all subtypes are associated with neuroendocrine tumors, each has characteristic organ involvement. Identifying patients with the syndrome can aid in proper screening and treatment.

Macular Amyloidosis and Epstein-Barr Virus

Background. Amyloidosis is extracellular precipitation of eosinophilic hyaline material of self-origin with special staining features and fibrillar ultrastructure. Macular amyloidosis is limited to the skin, and several factors have been proposed for its pathogenesis. Detection of Epstein-Barr virus (EBV) DNA in this lesion suggests that this virus can play a role in pathogenesis of this disease. Objective. EBV DNA detection was done on 30 skin samples with a diagnosis of macular amyloidosis and 31 healthy skin samples in the margin of removed melanocytic nevi by using PCR. Results. In patients positive for beta-globin gene in PCR, BLLF1 gene of EBV virus was positive in 23 patients (8 patients in case and 15 patients in the control group). There was no significant difference in presence of EBV DNA between macular amyloidosis (3.8%) and control (23.8%) groups (P = 0.08). Conclusion. The findings of this study showed that EBV is not involved in pathogenesis of macular amyloidosis.

Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma

INTRODUCTION

The American Thyroid Association appointed a Task Force of experts to revise the original Medullary Thyroid Carcinoma: Management Guidelines of the American Thyroid Association.

METHODS

The Task Force identified relevant articles using a systematic PubMed search, supplemented with additional published materials, and then created evidence-based recommendations, which were set in categories using criteria adapted from the United States Preventive Services Task Force Agency for Healthcare Research and Quality. The original guidelines provided abundant source material and an excellent organizational structure that served as the basis for the current revised document.

RESULTS

The revised guidelines are focused primarily on the diagnosis and treatment of patients with sporadic medullary thyroid carcinoma (MTC) and hereditary MTC.

CONCLUSIONS

The Task Force developed 67 evidence-based recommendations to assist clinicians in the care of patients with MTC. The Task Force considers the recommendations to represent current, rational, and optimal medical practice.

Acquired hyperpigmentations

Cutaneous hyperpigmentations are frequent complaints, motivating around 8.5% of all dermatological consultations in our country. They can be congenital, with different patterns of inheritance, or acquired in consequence of skin problems, systemic diseases or secondary to environmental factors. The vast majority of them are linked to alterations on the pigment melanin, induced by different mechanisms. This review will focus on the major acquired hyperpigmentations associated with increased melanin, reviewing their mechanisms of action and possible preventive measures. Particularly prominent aspects of diagnosis and therapy will be emphasized, with focus on melasma, post-inflammatory hyperpigmentation, periorbital pigmentation, dermatosis papulosa nigra, phytophotodermatoses, flagellate dermatosis, erythema dyschromicum perstans, cervical poikiloderma (Poikiloderma of Civatte), acanthosis nigricans, cutaneous amyloidosis and reticulated confluent dermatitis

Reactive eccrine syringofibroadenomatosis secondary to primary cutaneous amyloidosis: a novel association

We report the unprecedented case of reactive eccrine syringofibroadenoma (ESFA) secondary to primary cutaneous amyloidosis. A 62-year-old woman of Asian ethnicity presented with a pruritic rash on the back of long-standing duration. Physical examination revealed diffuse hyperpigmentation localized to the interscapular region; there were a multitude of hyperpigmented macules merged in a rippled pattern intermixed with scattered papules and cobblestone-like areas. A punch biopsy from a papule was taken. Histopathological examination revealed a network of epithelial strands and cords hanging from the epidermis and harboring foci of ductal differentiation. Eosinophilic collections of amorphous material were found between the epithelial strands, obscuring the superficial dermis. The microscopic picture was consistent with primary cutaneous amyloidosis associated with reactive ESFA. Results of histochemical and immunohistochemical staining confirmed the diagnosis. We speculate that pathogenetic mechanisms intrinsic to primary cutaneous amyloidosis, in addition to unknown genetic factors, resulted in clinical changes of lichen amyloidosus associated with an abnormal hyperplastic epithelial response with histopathological features of ESFA rather than the common epidermal change of acanthosis and hyperkeratosis.

Understanding the pathophysiology of itch

Itch is the most common symptom described by our patients. Treating this symptom can be challenging. A revolution is ongoing in understanding the pathophysiology of itch and will allow this challenge to be met. The present authors review and update the current understanding of the pathophysiology of itch.

Thalidomide improves clinical symptoms of primary cutaneous amyloidosis: report of familiar and sporadic cases

Primary cutaneous amyloidosis (PCA), either familial or sporadic, poses a therapeutic challenge. We conducted an open trial using thalidomide to treat three cases of familial and three cases of sporadic PCA, at initial dose of 100 mg/day. Dosage adjustment was made according to improvement of symptoms or patient's own choice. All except one sporadic case experienced moderate to significant relief on the symptoms of itching, over an observational period of 8 weeks by visual analog score (from 8.08 ± 0.88 to 1.60 ± 0.68, on average) as well as clinical amelioration of symptoms. Side effects included fatigue, drowsiness, numbness, and facial and leg edema in some of the patients. From the present observation, it seems that thalidomide is a promising drug to treat PCA.

Increased frequencies of IL-31-producing T cells are found in chronic atopic dermatitis skin

Interleukin (IL)-31 has been associated with pruritus, a characteristic feature of atopic dermatitis (AD). Local T cell responses may be responsible for the increased level of IL-31 mRNA observed in AD. We investigated the frequency of IL-31-producing T cells in AD lesions, as well as their cytokine profile. T cells were isolated from chronic AD lesions, autologous blood and healthy donor skin. Intracellular expression of IL-31, IFN-γ, IL-13, IL-17 and IL-22 was measured using flow cytometry. T cells from AD lesions contained significantly higher percentages of IL-31-producing T cells compared to autologous blood and donor skin. Many IL-31-producing T cells co-produced IL-13 and to lesser extent IL-22, but rarely IFN-γ or IL-17. A substantial part of the IL-31-producing T cells did not co-produce any of the other cytokines and could therefore not be linked to any of the known functionally different T cell subsets. The T cell infiltrates were also relatively enriched for Th2/Tc2 and Th22/Tc22 cells, while frequencies of Th1/Tc1 and Th17 cells were decreased. This is the first report describing the detection of IL-31 at protein level in skin-infiltrating T cells. We show here that T cells in chronic AD skin produce IL-31 and that AD lesions contain increased levels of these IL-31-producing T cells. This suggests that a substantial part of previously reported increased IL-31 mRNA levels in AD skin is T cell derived and that these cells may be involved in the pathogenesis of AD.

A clinico-epidemiological study of macular amyloidosis from north India

BACKGROUND

Macular amyloidosis (MA) is the most subtle form of cutaneous amyloidosis, characterized by brownish macules in a rippled pattern, distributed predominantly over the trunk and extremities. MA has a high incidence in Asia, Middle East, and South America. Its etiology has yet to be fully elucidated though various risk factors such as sex, race, genetic predisposition, exposure to sunlight, atopy and friction and even auto-immunity have been implicated.

AIM

This study attempts to evaluate the epidemiology and risk factors in the etiology of MA.

MATERIALS AND METHODS

Clinical history and risk factors of 50 patients with a clinical diagnosis of MA were evaluated. Skin biopsies of 26 randomly selected patients were studied for the deposition of amyloid.

RESULTS

We observed a characteristic female preponderance (88%) with a female to male ratio of 7.3:1, with a mean age of onset of MA being earlier in females. Upper back was involved in 80% of patients and sun-exposed sites were involved in 64% cases. Incidence of MA was high in patients with skin phototype III. Role of friction was inconclusive

CONCLUSION

Lack of clear-cut etiological factors makes it difficult to suggest a reasonable therapeutic modality. Histopathology is not specific and amyloid deposits can be demonstrated only in a small number of patients. For want of the requisite information on the natural course and definitive etiology, the disease MA remains an enigma and a source of concern for the suffering patients.

Skin lesions in hereditary endocrine tumor syndromes

OBJECTIVE

To review the main cutaneous manifestations of hereditary endocrine tumor syndromes and discuss currently known molecular mechanisms involved in their pathogenesis.

METHODS

On the basis of our collective experience and a comprehensive MEDLINE literature search of the English-language literature published between January 1957 and September 2010 using the search terms "skin," "cutaneous," "multiple endocrine neoplasia," "Carney complex," and "McCune-Albright syndrome," we reviewed the dermatologic findings in multiple endocrine neoplasia type 1 and type 2, Carney complex, and McCune-Albright syndrome.

RESULTS

Although the category of hereditary endocrine tumor syndromes consists of a broad spectrum of conditions, only the aforementioned few are prominently associated with cutaneous features. Because the cutaneous findings associated with these diseases are generally benign, they are often ignored or dismissed as ancillary findings in the context of severe systemic involvement. Accordingly, the pertinent literature is relatively scarce and often fails to provide a comprehensive insight about this issue. Nevertheless, timely recognition of such dermatologic manifestations may have a critical role in the early diagnosis and appropriate management of the related syndromes. Moreover, specific genotype-phenotype correlations may convey important prognostic implications.

CONCLUSION

Many physicians are unfamiliar with the cutaneous findings in the hereditary endocrine tumor syndromes described in this review. Nonetheless, knowledge of their existence can have a major role in establishing an early diagnosis of these syndromes and determining the patient's prognosis.

Case of primary localized cutaneous amyloidosis with protean clinical manifestations: lichen, poikiloderma-like, dyschromic and bullous variants

Primary localized cutaneous amyloidosis (PLCA) commonly presents as macular and lichen variants. We present a case of a 27-year-old Chinese woman with cutaneous features of the rarely reported poikiloderma-like, dyschromic and bullous forms of PLCA, and the commoner lichen variant. There were no syndromic associations or systemic involvement, and the various morphological subtypes occurred in isolation from one another. We review the clinical spectrum of PLCA, highlight its protean clinical manifestations in this patient, and discuss its postulated pathogenesis in relation to its histopathological features.

Targeted treatment of pruritus: a look into the future

Recent advances in pruritus research have elucidated mediators and neuronal pathways involved in itch transmission, and this fast emerging knowledge may possibly be translated into new therapies in the near future. In the skin and peripheral nerves, potential mediator and receptor therapeutic targets include the H4 histamine receptor, protease-activated receptor 2, serine proteases, cathepsin S, peripheral mu- and kappa-opioid receptors, interleukin-31, transient receptor potential vanilloid 1 and 3, fatty acid amide hydrolase, nerve growth factor and its receptor, acetylcholine, and the Mas-related G protein-coupled receptors. In the spinal cord, gastrin-related peptide and its receptor, as well as substance P and its receptor neurokinin receptor-1 serve as potential therapeutic targets. In the brain, reduction of itch perception and modulation of emotions may possibly be achieved through drugs acting on the anterior cingulate cortex. Clinically, management of pruritus should be instituted early and should address the skin pathology, peripheral neuropathy, central sensitization, and the cognito-affective aspects of the disease.

Targeted treatment of pruritus: a look into the future

Recent advances in pruritus research have elucidated mediators and neuronal pathways involved in itch transmission, and this fast emerging knowledge may possibly be translated into new therapies in the near future. In the skin and peripheral nerves, potential mediator and receptor therapeutic targets include the H4 histamine receptor, protease-activated receptor 2, serine proteases, cathepsin S, peripheral mu- and kappa-opioid receptors, interleukin-31, transient receptor potential vanilloid 1 and 3, fatty acid amide hydrolase, nerve growth factor and its receptor, acetylcholine, and the Mas-related G protein-coupled receptors. In the spinal cord, gastrin-related peptide and its receptor, as well as substance P and its receptor neurokinin receptor-1 serve as potential therapeutic targets. In the brain, reduction of itch perception and modulation of emotions may possibly be achieved through drugs acting on the anterior cingulate cortex. Clinically, management of pruritus should be instituted early and should address the skin pathology, peripheral neuropathy, central sensitization, and the cognito-affective aspects of the disease.

Chronic pruritus: a paraneoplastic sign

Chronic itch could be a presenting sign of malignancy. Pruritus of lymphoma is the common prototype of paraneoplastic itch and can precede other clinical signs by weeks and months. Paraneoplastic pruritus has also been associated with solid tumors and is an important clinical symptom in paraneoplastic skin diseases such as erythroderma, Grovers disease, malignant acanthosis nigricans, generalized granuloma annulare, Bazex syndrome, and dermatomyositis. In any case with high index of suspicion a thorough work-up is required. This review highlights the association between itch and malignancy and presents new findings related to pathophysiological mechanisms and the treatment of itch associated with malignancy. Combinative therapies reducing itch sensitization and transmission using selective serotonin and neuroepinephrine reuptake inhibitors, Kappa opioids, and neuroleptics are of prime importance in reducing this bothersome symptom.

Transcutaneous electrical nerve stimulation for reduction of pruritus in macular amyloidosis and lichen simplex

Lichen simplex (LS) is characterized by circumscribed, lichenified, pruritic patches that may develop on any part of the body. Macular amyloidosis (MA) is the form of primary localized cutaneous amyloidosis. Transcutaneous electrical nerve stimulation (TENS) uses a pulsed electric current generated transcutaneously by a device to cause impulses to be carried along large-diameter afferent nerves. In this article, we report the effects of TENS on the Dermatology Life Quality Index (DLQI) measures and visual analogue scale (VAS) scores in patients with pruritus, in whom LS and MA were diagnosed. All patients with MA and six (75%) patients with LS had relief of their pruritus with TENS therapy. At week 2, there was a significant difference in median VAS scores between baseline in the group of LS (P = 0.007). At 4 weeks of therapy, statistically significant differences were observed compared with the baseline and week 2 in the median VAS scores in the group of MA (P < 0.001). There was also a statistically significant improvement in median DLQI total scores with respect to baseline, which was achieved as early as week 2 in patients with LS and MA who were on the TENS treatment (P = 0.006, P = 0.001, respectively).

The molecular skin pathology of familial primary localized cutaneous amyloidosis

Familial primary localized cutaneous amyloidosis (FPLCA) is an autosomal dominant disorder associated with chronic itching and skin lichenification. In lesional skin, there are apoptotic basal keratinocytes and deposits of amyloid material on degenerate keratin filaments in the upper dermis. The genetic basis of FPLCA involves mutations in the OSMR and IL31RA genes but the disease pathophysiology is not fully understood. In this study, we identified new pathogenic heterozygous missense mutations in the OSMR gene (p.Val631Leu and p.Asp647Tyr) in two Dutch FPLCA families. We then compared gene expression profiles between FPLCA lesional skin (n = 4) and site-matched control skin (n = 6). There was twofold or greater upregulation of 34 genes and downregulation of 43 genes. Most changes in gene expression (verified by quantitative RT-PCR) reflected alterations in epidermal differentiation and proliferation consistent with lichenification, but we also noted a reduction in several interfollicular keratinocyte stem cell markers in FPLCA skin. Differences in gene expression were also noted for proteins involved in apoptosis and nerve conduction. Collectively, this study expands the molecular basis of FPLCA and provides new insight into the skin pathology of this condition.