A case report of Grover's disease from immunotherapy-a skin toxicity induced by inhibition of CTLA-4 but not PD-1

Rheumatic adverse events of immune checkpoint inhibitors in cancer immunotherapy

INTRODUCTION

The advent of immune checkpoint inhibitors (ICIs) in cancer treatment has marked a transformative era, albeit tempered by immune-related adverse events (irAEs), including those impacting the musculoskeletal system. The lack of precise epidemiologic data on rheumatic irAEs is attributed to factors such as potential underrecognition, underreporting in clinical trials, and the tendency to overlook manifestations without immediate life-threatening implications, further complicating the determination of accurate incidence rates, while the complete understanding of the mechanisms driving rheumatic irAEs remains elusive.

AREAS COVERED

This literature review comprehensively examines rheumatic irAEs in cancer patients undergoing ICI therapy, encompassing epidemiology, risk factors, mechanisms, clinical manifestations, and current management guidance for prevalent conditions such as inflammatory arthritis, polymyalgia rheumatica, and myositis. Less frequent rheumatic and musculoskeletal irAEs are also explored, alongside insights into ongoing clinical trials testing therapeutic and preventive strategies for irAEs. A thorough literature search on Medline and the National Cancer Institute Clinical Trials Database was conducted up to October 2023 to compile relevant information.

EXPERT OPINION

In light of the evolving landscape of cancer immunotherapy, there is a compelling need for prospective longitudinal studies to enhance understanding and inform clinical management strategies for rheumatic irAEs.

Cutaneous Side Effects of Modern Targeted Therapy and Immunotherapy in Patients with Dermatological Malignancies

The advent of immunotherapy and targeted therapies in treating dermatological malignancies has dramatically changed the landscape of dermato-oncology in recent years. Their superior efficacy compared to previous therapeutic options, such as chemotherapy, has resulted in their use in treating devastating malignancies, such as melanoma or unresectable/metastatic basal cell and squamous cell carcinoma. Skin toxicity is a critical safety consideration, among other adverse reactions, that can occur under treatment with these agents. This article aims to summarize the cutaneous side effects of immune checkpoint inhibitors and targeted dermato-oncological therapies. Although the skin side effects of these agents are primarily mild, they can occasionally affect the decision for treatment continuation and the quality of life of the affected patients. Therefore, physicians must be acquainted with the specific cutaneous toxicity profile of such treatments to mitigate their impact on the patients and optimize the overall outcome of dermato-oncological therapy.

An Unusual Trigger of Grover's Disease (GD)

Grover's disease (GD) is a rare skin condition that presents as a pruritic, erythematous papular, or papulovesicular rash. We report a unique case of GD triggered by honeybee stings. An 80-year-old Caucasian male presented with a pruritic papulovesicular rash on his trunk and arms after being stung by honeybees. He had a history of honeybee venom allergy and developed immediate erythema at the sting sites, which progressed over two days. His laboratory tests were unremarkable, including a complete blood count and comprehensive metabolic profile. Despite using oral antihistamines, emollients, and topical steroids, his rash continued to progress onto his neck, face, scalp, and back. A skin biopsy of the rash revealed suprabasilar and intraspinous acantholysis with focal corps ronds and upper dermis lymphocytic infiltrate -- the histopathologic finding of GD. He had failed first-line treatment for GD. However, after five months and significant morbidity, he was successfully treated with systemic steroids, high-potency topical steroids, emollients, and antihistamines for extensive and prolonged GD. This case report highlights honeybee venom as a possible trigger of GD and discusses a potential immune-mediated etiopathogenesis, which can be used to guide further research and management of this rare disease.

Immune-Related Uncommon Adverse Events in Patients with Cancer Treated with Immunotherapy

Immunotherapy has dramatically changed the therapeutic landscape of oncology, and has become standard of care in multiple cancer types in front or late lines of therapy, with some longstanding responses and outstanding results. Notwithstanding, its use has brought a totally unique spectrum of adverse events, characterized by a myriad of diverse manifestations affecting nearly every organ and system of the body, including the endocrine, nervous, cardiac, respiratory and gastrointestinal systems. Uncommon adverse events, defined as those occurring in less than 1% of patients, comprise an even more heterogeneous group of diseases that are being seen more recurrently as the use of immune check-point inhibitors increases and indications spread in different tumor types and stages. Here, we comprehensively review some uncommon, but exceedingly important, immune-related adverse events, with special emphasis in the clinical approach and diagnostic workup, aiming to reunite the evidence published previously, allowing an increase in awareness and knowledge from all specialists implicated in the diagnosis, treatment, and care of cancer patients treated with immunotherapy.

Challenging Dermatologic Considerations Associated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have emerged as a new paradigm in oncologic care for many malignancies. However, nonspecific immune activation has led to "collateral damage" in the form of immune-related adverse events, with skin being a commonly affected organ. Cutaneous immune-related adverse events include a wide spectrum of clinical presentations and challenging considerations, often necessitating dermatology referral to support diagnosis and management, particularly for atypical presentations or more severe, cutaneous immune-related adverse events that may require specialized dermatologic evaluations including biopsy and histopathology. Close collaborations between oncologists and dermatologists may optimize clinical decision making in the following challenging management settings: non-steroidal therapies for corticosteroid-refractory, cutaneous immune-related adverse events, immune checkpoint inhibitor rechallenge, balancing cutaneous immune-related adverse events and treatments, and immune checkpoint inhibitors in patients with pre-existing autoimmune disease, skin conditions, and organ transplants. These complex clinical decisions that often lack rigorous data should be made in close collaboration with dermatologists to minimize unnecessary morbidity and mortality. This article provides a review of approaches to challenging dermatologic considerations associated with immune checkpoint inhibitor therapies.

"Skin rashes" and immunotherapy in melanoma: distinct dermatologic adverse events and implications for therapeutic management

Immune checkpoint inhibitors have shown efficacy in the treatment of different cancers by stimulating the antitumoral activity of the patient's immune system, representing a major breakthrough in the field of cancer therapy. Monoclonal antibodies including anti-cytotoxic T-lymphocyte-associated protein 4, anti-programmed cell death protein 1 and its ligand inhibitors have been approved for advanced melanoma among other solid cancers. Although immunotherapy demonstrated a good safety profile, a new spectrum of multisystemic immune-related adverse events has been recently reported due to their use. Cutaneous reactions represent one of the leading adverse events, often reported in literature as "skin rash", and rarely further characterized in distinct dermatologic entities. Herein we describe the distinctive cutaneous rashes occurring during immunotherapies for advanced melanoma, discussing implications in the treatment management.

Mechanisms underlying immune-related adverse events during checkpoint immunotherapy

Immune checkpoint (IC) proteins are some of the most important factors that tumor cells hijack to escape immune surveillance, and inhibiting ICs to enhance or relieve antitumor immunity has been proven efficient in tumor treatment. Immune checkpoint blockade (ICB) agents such as antibodies blocking programmed death (PD) 1, PD-1 ligand (PD-L) 1, and cytotoxic T lymphocyte-associated antigen (CTLA)-4 have been approved by the U.S. Food and Drug Administration (FDA) to treat several types of cancers. Although ICB agents have shown outstanding clinical success, and their application has continued to expand to additional tumor types in the past decade, immune-related adverse events (irAEs) have been observed in a wide range of patients who receive ICB treatment. Numerous studies have focused on the clinical manifestations and pathology of ICB-related irAEs, but the detailed mechanisms underlying irAEs remain largely unknown. Owing to the wide expression of IC molecules on distinct immune cell subpopulations and the fact that ICB agents generally affect IC-expressing cells, the influences of ICB agents on immune cells in irAEs need to be determined. Here, we discuss the expression and functions of IC proteins on distinct immune cells and the potential mechanism(s) related to ICB-targeted immune cell subsets in irAEs.

Skin Manifestation Induced by Immune Checkpoint Inhibitors

In accordance with recent therapeutic progress of immune checkpoint inhibitors for certain cancers, various disorders are induced as immune-related adverse events (irAEs) affecting the skin, gut, thyroid gland, lung, and liver. Among such irAEs, mucocutaneous manifestation is the most common. Cutaneous manifestations are categorized into several groups, ie, inflammatory reactions, immunobullous reactions, alterations of epidermal keratinocytes, and alterations of epidermal melanocytes; however, there are additionally various cutaneous toxicities, unclassified into those groups. Blocking of programmed cell death 1 (PD-1)/programmed cell death ligand 1(PDL1) can lead to the induction of autoimmune reaction, via activation of cytotoxic T cells, inhibition of regulatory T cell function, and alteration of cytokine balance. Similarly, blockade of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) reduces the suppressive function of regulatory T cells. Due to those mechanisms, various autoimmune conditions can be induced, in addition to nonspecific drug eruptions. Dermatologists should be aware of various types of those mucocutaneous manifestations, either common or rare, as well as the management of such conditions. Herein, various mucocutaneous manifestations of irAEs and cases involving Japanese patients have been described, based on a single institute's experience.

Cutaneous Adverse Events Associated with Immune Checkpoint Inhibitors: A Review Article

Immune checkpoint inhibitors (ICIs) have emerged as novel options that are effective in treating various cancers. They are monoclonal antibodies that target cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), and programmed cell death-ligand 1 (PD-L1). However, activation of the immune systems through ICIs may concomitantly trigger a constellation of immunologic symptoms and signs, termed immune-related adverse events (irAEs), with the skin being the most commonly involved organ. The dermatologic toxicities are observed in nearly half of the patients treated with ICIs, mainly in the form of maculopapular rash and pruritus. In the majority of cases, these cutaneous irAEs are self-limiting and manageable, and continuation of the ICIs is possible. This review provides an overview of variable ICI-mediated dermatologic reactions and describes the clinical and histopathologic presentation. Early and accurate diagnosis, recognition of severe toxicities, and appropriate management are key goals to achieve the most favorable outcomes and quality of life in cancer patients.

Understanding of Immune Escape Mechanisms and Advances in Cancer Immunotherapy

Tumor immune escape has emerged as the most significant barrier to cancer therapy. A thorough understanding of tumor immune escape therapy mechanisms is critical for further improving clinical treatment strategies. Currently, research indicates that combining several immunotherapies can boost antitumor efficacy and encourage T cells to play a more active part in the immune assault. To generate a more substantial therapeutic impact, it can establish an ideal tumor microenvironment (TME), encourage T cells to play a role, prevent T cell immune function reversal, and minimize tumor immune tolerance. In this review, we will examine the mechanisms of tumor immune escape and the limits of tumor immune escape therapy, focusing on the current development of immunotherapy based on tumor immune escape mechanisms. Individualized tumor treatment is becoming increasingly apparent as future treatment strategies. In addition, we forecast the future research direction of cancer and the clinical approach for cancer immunotherapy. It will serve as a better reference for researchers working in cancer therapy research.

Drug-induced Grover's disease: a case report and review of the literature

BACKGROUND

Grover's disease (GD) is a relatively rare transient dermatosis that can be idiopathic or acquired. Acquired GD may occur secondary to internal triggers such as medications and malignancies and external factors such as friction.

OBJECTIVE

The purpose of this report is to describe the clinical and histological presentation of drug-induced Grover's disease (DIGD) and discuss potential pathogenic mechanisms.

METHODS

A systemic review of the literature was performed to identify medications implicated in DIGD.

RESULTS

We identified 13 reports of patients with DIGD. Most patients presented with a papular or papulovesicular morphology involving the trunk and extremities. Pruritus was the most common symptom. The majority of the offending agents were cancer therapeutics. Discontinuation of the culprit medication was sufficient for rash clearance and symptom resolution in most cases.

CONCLUSION

The overlap in morphology and associated symptoms in DIGD and GD makes the diagnosis of DIGD challenging and has potentially led to underdiagnosis. However, in cases of more extensive involvement and treatment recalcitrance, a drug-induced eruption should be considered.

Cutaneous Toxicities in the Setting of Immune Checkpoint Blockade:: The Era of Oncodermatopathology

Advancements in cancer therapy with monoclonal immune checkpoint antibody blockade have impacted the practice of all medical specialties. Cutaneous immune-related adverse events (irAEs) are a frequent, unintended, off-target consequence of immune checkpoint inhibitor (ICI) therapy that have ushered in the era of oncodermatopathology. Knowledge of the diverse morphologic types of cutaneous irAEs from ICI therapy allows further classification of cutaneous irAEs according to major histopathologic reaction patterns. Early studies suggest that immune mechanisms of lichenoid dermatitis irAE, psoriasiform dermatitis irAE, and bullous pemphigoid irAE show some similarities and differences from their histopathologic counterparts not associated with ICI therapy.

Immune-related adverse events and immune checkpoint inhibitor tolerance on rechallenge in patients with irAEs: a single-center experience

BACKGROUND

Given the widespread use of immune checkpoint inhibitors (ICIs), newer immune related adverse events (irAEs) have come to light, including flare-ups of preexisting autoimmune disorders (AIDs) and delayed immune-related events. We aimed to identify the frequency and severity of new IRAEs, including AID flares in cancer patients treated with ICIs at our institution. We also studied the tolerability of ICIs upon rechallenge in patients with irAEs and hospital admissions due to irAEs in a community setting in rural Maine.

METHODS

We conducted a retrospective chart review analysis of all patients with cancer who received anti-PDL1/PDL1 inhibitors nivolumab, pembrolizumab, atezolizumab, and durvalumab at our tertiary care center from November 2015 to March 2019. Demographic data, cancer type and stage, irAEs, hospital admissions due to irAEs, and drug treatment information was extracted.

RESULTS

We included 465 patients who received ICIs, 115 (out of 465 25%) developed new irAEs. Preexisting AID were identified in 47 (out of 465) (10%), AID flares were observed in 12 patients (25% of 47). 17 (out of 47 36%) were on immunosuppression for underlying AID, 5 (out of 17, 29%) developed flares. Overall, 148 (32% of 465) irAEs occurred, as some patients had multiple toxicities. Majority were treated for Lung cancer (63%), followed by melanoma and genitourinary cancers. Due to irAE severity, treatment was permanently discontinued in 15% (out of 465) patients. Hospital admissions due to irAEs were required for 34 patients (7.3% of 465). ICI rechallenge was performed in 27 patients (6% of 465), and majority tolerated well.

CONCLUSION

Our study shows that ICIs were generally well tolerated and can be used safely even in patients with preexisting AIDs; it is encouraging to see majority tolerated rechallenge with ICIs well.

The Clinical and Histopathological Features of Cutaneous Immune-Related Adverse Events and Their Outcomes

Immune checkpoint inhibitors (ICIs) cause a variety of inflammatory eruptions. The understanding of ICI-induced inflammatory eruptions with detailed histopathological findings is not adequate, particularly in Asian populations. In this study, we retrospectively reviewed 51 patients who were histopathologically diagnosed with cutaneous immune-related adverse events (irAEs) following ICI therapy between 2014 and 2020 at the Department of Dermatology of Kyushu University Hospital. Of the 51 patients (30 men, 21 women), maculopapular rash (38/51, 74.5%), erythema multiforme (2/51, 3.9%), lichenoid reaction (3/51, 5.9%), psoriasiform reaction (3/51, 5.9%), bullous pemphigoid (3/51, 5.9%), scleroderma-like reaction (1/51, 2.0%), and Stevens–Johnson syndrome (1/51, 2.0%) were observed. The clinical and histopathological findings of these eruptions were equivalent to typical cases of common drug eruptions. The onset of maculopapular rash was relatively early (more than half of events occurred within 1 month), whereas lichenoid reactions and autoimmune diseases occurred relatively late (4–8 months). With appropriate treatment and/or interruption of ICIs, most rashes improved (50/51, 98.0%). The ICI-induced inflammatory eruptions shared similar clinical and histopathological features with classical inflammatory eruptions, but a variety of inflammatory eruptions may occur with different degrees of severity. Dermatologists play an important role in providing specialized care for cutaneous irAEs.

Cutaneous Adverse Events of Immune Checkpoint Inhibitors: A Literature Review

Immune checkpoints assist with self-tolerance and minimize collateral tissue damage when immune responses are activated. Although immune checkpoint inhibitors (CPIs) are characterized by a favorable risk/benefit ratio, immune checkpoint blockade has been associated with a new subset of autoimmune-like toxicities, named immune-related adverse events (irAEs). Dermatologic reactions are among the most prevalent irAEs triggered by CPIs. In a majority of cases they are self-limiting and readily manageable. However, it is not uncommon that they result in severe skin involvement and impairment of patients' quality of life. Awareness of the spectrum of cutaneous irAEs is mandatory for every clinician involved in the management of oncologic patients. The role of the dermatologists is essential because early recognition and appropriate management of skin toxicity may prevent dose modifications and discontinuation of CPIs. The latter is particularly relevant, considering that recent data suggest favorable oncologic response in patients developing irAEs.

New patterns of cutaneous drug eruptions

Cutaneous adverse drug reactions produce a significant clinical, financial, and psychological burden on our healthcare industry. The importance of considering a drug reaction in the cause of any dermatitis is underscored by the diversity of clinical manifestations and the prolific rate of drug discovery and approval. We present an update on the variety of drug reactions encountered in the inpatient and outpatient setting. Immunomodulatory drugs used in oncology will be reviewed separately as their clinical manifestations cross many reaction patters and morphologies.

Clinical features and treatments of transient acantholytic dermatosis (Grover's disease): a systematic review

Grover's disease (GD) is an itchy acantholytic disorder occurring on the trunk of middle-aged men. Based on the best evidence, this study aimed to provide a summary of the clinical characteristics, disease course and treatments of GD. A systematic review was performed according to PRISMA guidelines for original articles published between 01.01.1970-08.15.2019, assessing clinical features and/or any type of intervention for GD. A total of 263 articles were retrieved, and 116 original reports that were deemed relevant and satisfied the inclusion criteria were included in the analysis (88 case reports, 26 case series and two retrospective reviews). From these articles, 317 patients were identified, with a male-to-female ratio of 3.95. The mean age was 59 years (range 11-92). Typical lesions were itchy papules and vesicle-papules, generally located on the trunk. Spontaneous resolution within one week to eight months was described in 42 % of cases. Topical corticosteroids (TCSs) were the most frequent treatment (response rate of 70 %) followed by systemic retinoids and corticosteroids with response rates of 86 % and 64 %, respectively. According to the results of this review, TCS appears to be the most frequently employed treatment, and we suggest TCS as first-line therapy. Second-line treatments could include systemic retinoids or systemic corticosteroids.

Case of Bullous Grover Disease

ABSTRACT

Grover disease is an acquired acantholytic dermatosis affecting middle-aged men, with pruritus being the most commonly associated symptom. Grover disease tends to wax and wane and can last between several months to several years. Although Grover disease is usually papular, we report here a patient who presented with mainly vesicular and bullous lesions on his back originally concerning for folliculitis, contact dermatitis, or disseminated herpes simplex viral infection. Skin biopsy demonstrated acantholysis, suprabasal blisters, and a predominantly lymphocytic dermal infiltrate. Tzanck preparation for giant cells, immunohistochemistry for viral markers, and direct immunofluorescence staining were all negative. A diagnosis of bullous Grover disease was made based on clinicopathological correlation. Minocycline was recommended based on report of its efficacy. However, patient declined treatment and his rash self-resolved within a couple of months. This case brings awareness to this atypical variant of Grover disease and encourages physician to include Grover disease in their differential of vesiculobullous disorders.

Dermatologic toxicities to immune checkpoint inhibitor therapy: A review of histopathologic features

Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.

Immune-related adverse events of checkpoint inhibitors: Insights into immunological dysregulation

Immune checkpoint inhibitors (ICIs) targeting against programmed cell death-1(PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) have shown efficacy in cancer treatment. However, a spectrum of immune-related adverse events (irAEs) have raised concerns about their clinical application. IrAEs are distinct from traditional chemo- and radiotherapy-induced toxicities, as they are related in particular to the dysregulation of immune system and autoimmunity. The underlying pathogenesis of irAEs remains elusive. Understanding of the potential underlying mechanism is of great importance for the management of irAEs and the development of new ICIs with insignificant irAEs. In this review, we summarize the current evidence to provide insights into the biological basis of irAEs and provide a potential explanation for their pathogenesis, with focus on the relationship between checkpoint molecules and immune cell regulation.

Management of immune checkpoint inhibitor-related adverse events: A review of case reports

Immune checkpoint inhibitors represent a major breakthrough in cancer therapy. Immune‐related adverse events (irAEs) may occur during treatment due to their unique mechanism of action. Management of irAEs is based on clinical experience because it is not easy to conduct prospective trials to evaluate the best treatment strategy. Using a combination of search terms in the PubMed and Embase databases, we reviewed all cases in the English language citing toxicities associated with either pembrolizumab, nivolumab, ipilimumab, atezolizumab, tremelimumab, durvalumab, avelumab or any combination of these agents published before 20 May 2019. A total of 128 reports with 239 cases were included in the study. Here, we summarize the spectrum of toxicities, safety in special patients, rechallenging after irAEs and agents used for treatment of irAEs in those reports.

Pathology of immune-mediated tissue lesions following treatment with immune checkpoint inhibitors

Immune check point inhibitor (CPI) therapy has revolutionized treatment paradigms for several cancers, but at the cost of triggering a diverse spectrum of immune-mediated injury to non-cancer tissues. The complex biology of these toxicities remains incompletely understood, partly because tissue acquisition from affected areas can be challenging to retrieve, thus hindering development of targeted therapy. Here, we review the literature describing pathology of immune-mediated tissue lesions including gastrointestinal, skin, rheumatic, pulmonary, cardiac, renal and hepatic lesions and highlight key immunological insights.

IL17A Blockade Successfully Treated Psoriasiform Dermatologic Toxicity from Immunotherapy

Dermatologic toxicities are the most common immune-related adverse events (irAE) secondary to immune checkpoint inhibitors (ICI). First-line treatment for grade 3 or 4 skin irAEs is high-dose corticosteroids, which have their own side effects. Prolonged treatment with corticosteroids may abrogate antitumor ICI activity. The cellular causes of these dermatologic toxicities, which can manifest as a variety of clinical presentations, remain unclear. Beyond steroids, recommended treatment options are limited. We report a case of psoriasiform dermatologic toxicity, induced by inhibition of PD-1 with the mAb pembrolizumab, which resolved after treatment with systemic interleukin IL17A blockade. Introduction of IL17A blockade did not alter the patient's melanoma response to pembrolizumab. This case suggests a possible pathogenic role of Th17 cells the irAE of the skin in this metastatic melanoma patient.

What's New in Dermatopathology: Inflammatory Dermatoses

Inflammatory skin diseases encompass a vast array of conditions. The field continues to expand and evolve with resurgence of conditions, through newly recognized medication adverse effects, and via more detailed descriptions of known dermatoses. The importance of clinicopathologic correlation and an up to date knowledge of dermatologic conditions cannot be overstated. This review focuses on an array of recent important developments in the histologic diagnosis of inflammatory conditions that affect the skin.

Suprabasal acantholytic dermatologic toxicities associated checkpoint inhibitor therapy: A spectrum of immune reactions from paraneoplastic pemphigus-like to Grover-like lesions

Checkpoint inhibitors (CPIs) restore the function of effector immunocytes to target and destroy cancer cells. Immune-related adverse events (irAEs) are a consequence of immune reactivation, with unpredictable inflammatory response, loss of self-tolerance, and development of autoimmunity. Adverse events from CPIs that present as dermatologic toxicities have diverse clinical and histopathologic features. CPI-associated dermatologic toxicities may exhibit histopathologic features of lichenoid dermatitis, bullous pemphigoid, and granulomatous/sarcoid-like reactions. Suprabasal acantholytic dermatologic toxicities associated with CPIs are particularly rare but represent an emerging histopathologic pattern and include lichenoid dermatitis with suprabasal acantholysis/vesicle formation to Grover disease (transient acantholytic dermatosis). Here, we report two patients who developed suprabasal acantholytic dermatologic toxicities during CPI therapy. One patient exhibited a CPI-associated autoimmune blistering disease with paraneoplastic pemphigus (PNP)-like features restricted to histopathology and immunofluorescence, while the other patient had Grover-like lesions. A review of the literature revealed a spectrum of suprabasal acantholytic dermatologic toxicities associated CPIs that may present as lichenoid dermatitis with acantholysis/vesicle formation, Grover-like eruptions, and lesions with PNP-like features restricted to histopathology and immunofluorescence. It is important for clinicians and pathologists to recognize the types of dermatologic toxicities associated with CPIs to direct appropriate therapeutic strategies.

Immune Checkpoint Inhibitor Toxicity Review for the Palliative Care Clinician

Immune checkpoint inhibitors (ICIs) have opened an exciting chapter in the treatment of patients with advanced cancer. For the palliative care clinician, however, ICIs present several new challenges, including new ways to define treatment success, as well as treatment-related toxicities that differ in nature and timing from traditional chemotherapy. In this article, we review the mechanism of action of ICIs, as well as selected published data supporting the efficacy of ICIs in patients with advanced cancer. In addition, we summarize existing data of ICI toxicity prevalence, patterns of severity, and timing of onset. Finally, we briefly review key principles from published guidelines on the management of ICI toxicities.

Dermatologic Reactions to Immune Checkpoint Inhibitors : Skin Toxicities and Immunotherapy

The development of immune checkpoint inhibitors [monoclonal antibodies targeting cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1)] represents a major breakthrough in cancer therapy. Although they present a favorable risk/benefit ratio, immune checkpoint blockade therapies have a very specific safety profile. Due to their unique mechanism of action, they entail a new spectrum of adverse events that are mostly immune related [immune-related adverse events (irAEs)], notably mediated by the triggering of cytotoxic CD4+/CD8+ T cell activation. Cutaneous toxicities appear to be one of the most prevalent irAEs, both with anti-PD-1 and anti-CTLA-4 agents or with the newly developed anti-PD-L1 agents, which corresponds to a class effect. They are observed in more than one-third of the treated patients, mainly in the form of a maculopapular rash (eczema-like spongiotic dermatitis) and pruritus. A wide range of other dermatologic manifestations can also occur, including lichenoid reactions, psoriasis, acneiform rashes, vitiligo-like lesions, autoimmune skin diseases (e.g., bullous pemphigoid, dermatomyositis, alopecia areata), sarcoidosis or nail and oral mucosal changes. In addition, the use of anti-CTLA-4 and anti-PD-1 therapies in combination is associated with the development of more frequent, more severe and earlier cutaneous irAEs compared to single agents. In most cases, these dysimmune dermatologic adverse events remain self-limiting and readily manageable. Early recognition and adequate management, however, are critical to prevent exacerbation of the lesions, to limit treatment interruption and to minimize quality of life impairment. This review describes the variable clinical and histopathologic aspects of dermatologic irAEs induced by immune checkpoint inhibitors. Appropriate treatment and counseling are also proposed, with a step-by-step approach for optimized management by both practicing oncologists and dermatologists.

Immune-related adverse events with immune checkpoint inhibitors in thoracic malignancies: focusing on non-small cell lung cancer patients

Immune checkpoint inhibitors (ICIs) have revolutionized treatment landscape among non-small cell lung cancer (NSCLC) patients in first- and second-line setting, and may become soon new treatment options in other thoracic malignancies such as small cell lung cancer (SCLC) or mesothelioma. The use of these drugs has indubitably changed the toxicity profile the oncologists are familiar with, and new spectra of immune-related adverse events are being reported with the widespread use of immunotherapies in solid tumors. Clinical management and understanding of immune-related adverse events is new and complex but expertise is still limited. In this review, we are summarizing the incidence and management of main side effects related to ICIs focusing on NSCLC patients.

[Dermatologic toxicities of immune checkpoint inhibitors]

The development of immune checkpoint inhibitors (monoclonal antibodies targeting PD-1/PD-L1 or CTLA-4) represents a significant advance in the treatment of multiple cancers. Given their particular mechanism of action, which involves triggering CD4+/CD8+ T-cell activation and proliferation, they are associated with a specific safety profile. Their adverse events are primarily immune-related, and can affect practically all organs. In this context, dermatological toxicity is the most common, though it mostly remains mild to moderate and does not require discontinuation of treatment. More than a third of patients are faced with cutaneous adverse events, usually in the form of a maculopapular rash, pruritus or vitiligo (only in patients treated for melanoma). Much more specific dermatologic disorders, however, may occur such as lichenoid reactions, induced psoriasis, sarcoidosis, auto-immune diseases (bullous pemphigoid, dermatomyositis, alopecia areata), acne-like rash, xerostomia, etc. Rigorous dermatological evaluation is thus mandatory in the case of atypical, persistent/recurrent or severe lesions. In this article, we review the incidence and spectrum of dermatologic adverse events reported with immune checkpoint inhibitors. Finally, a management algorithm is proposed.

Erratum to: A case report of Grover's disease from immunotherapy-a skin toxicity induced by inhibition of CTLA-4 but not PD-1

[This corrects the article DOI: 10.1186/s40425-016-0157-6.].

Diverse types of dermatologic toxicities from immune checkpoint blockade therapy

Immunomodulatory drugs that leverages host immune mechanisms to destroy tumor cells have been met with great promise in the treatment of cancer. Immunotherapy, targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1) have shown tremendous improvements in the survival of patients with advanced solid tumors. However, the development of dermatologic toxicity (DT) is a consequence to immunotherapy. Review of published reports of the DT to immunotherapy revealed patients receiving anti-CTCLA-4 antibody or anti-PD-1/PD-L1 antibody often develop a DT of any type and grade. In this article, of the 3825 patients who were treated with anti-PD-1 and of 556 patients receiving anti-PD-L1, DT of any type and grade were reported in 1474 (∼39%) and 95 (∼17%) of patients, respectively. The emergence of specific types of DT to immunotherapy is beginning to be recognized can be categorized into four groups: (a) inflammatory, (b) immunobullous, (c) alteration of keratinocytes and (d) alteration of melanocytes. Lichenoid dermatitis and bullous pemphigoid appear to be DT more associated with anti-PD-1/PD-L1 antibody. The DT profile in patients receiving immunotherapy is diverse, and early recognition of specific types of DT that clinicians may encounter is critical for optimal patient care.