Severe blistering eruptions induced by immune checkpoint inhibitors: a multicentre international study of 32 cases

Cutaneous adverse drug reactions

Cutaneous adverse drug reactions (ADRs) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Maculopapular exanthema and urticaria are the most common types of cutaneous ADR. Serious cutaneous ADRs, which may cause permanent sequelae or have fatal outcome, may represent 2% of all cutaneous ADR and must be quickly identified to guide their management. These serious reactions include bullous manifestations (epidermal necrolysis i.e. Stevens-Johnson syndrome and toxic epidermal necrolysis), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). Some risk factors for developing cutaneous ADRs have been identified, including immunosuppression, autoimmunity or genetic variants. All drugs can cause cutaneous ADRs, the most commonly implicated being antibiotics (especially aminopenicillins and sulfonamides), anticonvulsants, allopurinol, antineoplastic drugs, non-steroidal anti-inflammatory drugs and iodinated contrast media. Pathophysiology is related to immediate or delayed "idiosyncratic" immunologic mechanisms, i.e., usually not related to dose, and pharmacologic/toxic mechanisms, commonly dose-dependent and/or time-dependent. If an immuno-allergic mechanism is suspected, allergological explorations (including epicutaneous patch testing and/or intradermal test) are often possible to clarify drug causality, however these have a variable sensitivity according to the drug and to the ADR type. No in vivo or in vitro test can consistently confirm the drug causality. To determine the origin of a rash, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis (especially infectious etiologies) is required, completed with a literature search. Reporting to pharmacovigilance system is therefore essential both to analyze drug causality at individual level, and to contribute to knowledge of the drug at population level, especially for serious cutaneous ADRs or in cases involving newly marketed drugs.

Immune checkpoint inhibitor-induced epidermal necrolysis: A narrative review evaluating demographics, clinical features, and culprit medications

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment but can cause immune-related adverse events (irAEs). Severe cutaneous irAEs, including epidermal necrolysis, are rare but potentially life-threatening. There is limited understanding of the clinical features and management of ICI-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), so we aimed to analyze 95 cases of ICI-induced SJS/TEN (35 cases of SJS, 26 cases of TEN, two cases of SJS/TEN overlap, and 32 cases of unspecified) to increase knowledge of this condition among oncologists and dermatologists. We conducted a comprehensive search of PubMed for all relevant case reports published until the end of December 2022, and collected data on patient demographics, cancer type, ICI regimen, time to onset of SJS/TEN, clinical presentation, management strategies, and outcomes. PD-1 inhibitors were the most common ICIs associated with SJS/TEN (58.9%), followed by the combination of PD-1 and CTLA-4 inhibitors (11.6%), and PD-L1 inhibitors (6.3%). Lung cancer and melanoma were the most frequent malignancies treated (35.8% and 25.4%, respectively). SJS/TEN occurred most frequently within the first 4 weeks (51.7%), and corticosteroid monotherapy was the most commonly chosen systemic treatment (56.4%). The overall mortality rate of ICI-induced SJS/TEN was 30.8%. Our findings highlight the frequency and severity of ICI-induced SJS/TEN and the urgent need for predictive molecular biomarkers aimed at preventive measures and early intervention.

Drug reactions with eosinophilia and systemic symptoms induced by immune checkpoint inhibitors: an international cohort of 13 cases

Among dermatologic adverse events induced by immune checkpoint inhibitors (ICI), drug reactions with eosinophilia and systemic symptoms (DRESS) have been very rarely reported. The objective of this study is to better define the clinical and histologic features, treatment and prognosis of ICI-related DRESS. This retrospective case series was conducted between 01 January 2015 and 31 December 2021 by the dermatology departments of five international networks involved in drug reactions. Inclusion criteria were age ≥18 years old, DRESS with Regiscar score ≥4 (probable or certain) and ICI as a suspect drug. Clinical, biologic and follow-up data were extracted from the medical charts. Thirteen patients were included. The median time to onset was 22 days (3-11). No patients had a high-risk drug introduced in the past 3 months. A majority of patients presented fever (92%), diffuse exanthema (77%) and facial edema (69%). Biologic features included hypereosinophilia in eight patients (61.5%), hyperlymphocytosis in 3 (23%), elevated liver function tests in 11 (85%, grade 1 or 2 in most cases) and renal involvement in 5 (38%). Two patients (15%) had lung involvement. PCR evidence of viral replication was detected in five patients (38.5%). Treatment involved discontinuation of the suspect ICI and systemic steroids with variable dose and duration regimens. Among the four patients in which ipilimumab + nivolumab combination therapy was initially suspected, one was rechallenged with nivolumab monotherapy with good tolerance. Five patients were switched to another anti-PD-1 plus low-dose systemic steroids, with good tolerance in four cases. No patient died because of DRESS. DRESS induced by ICI are rare and of moderate severity. A consensus for management is still pending.

Pustular Lichenoid Eruptions Induced by Immune Checkpoint Inhibitors: Two Case Reports and a Review of the Literature

Immune checkpoint inhibitors (ICIs) have become the standard treatment for many types of cancer. After several years of using these therapies, many adverse events related to ICIs have been observed. Dermatologic toxicities such as nonspecific morbilliform rash, vitiligo, Stevens-Johnson syndrome/toxic epidermal necrolysis, and more rarely, lichenoid eruptions have been described in the literature. We report 2 cases of pustular lichenoid eruptions, 1 in a patient with nonsmall cell lung carcinoma and 1 in a patient with metastatic melanoma, induced by pembrolizumab and nivolumab, respectively. The 2 patients were treated with topical corticosteroids, and complete healing of lesions was slowly obtained. Due to the severity of the cutaneous eruptions, pembrolizumab and nivolumab were discontinued. We identified 6 cases of pustular lichenoid eruptions induced by ICIs in the published literature and in the French Pharmacovigilance Database and reviewed their main clinical features and courses.

A Review of Bullous Dermatologic Adverse Events Associated with Anti-Cancer Therapy

The rapid evolution of anti-cancer therapy (including chemotherapy, targeted therapy, and immunotherapy) in recent years has led to a more favorable efficacy and safety profile for a growing cancer population, and the improvement of overall survival and reduction of morbidity for many cancers. Anti-cancer therapy improves outcomes for cancer patients; however, many classes of anti-cancer therapy have been implicated in the induction of bullous dermatologic adverse events (DAE), leading to reduced patient quality of life and in some cases discontinuation of life-prolonging or palliative therapy. Timely and effective management of adverse events is critical for reducing treatment interruptions and preserving an anti-tumor effect. Bullous DAE may be limited to the skin or have systemic involvement with greater risk of morbidity and mortality. We present the epidemiology, diagnosis, pathogenesis, and management of bullous DAE secondary to anti-cancer therapies to enable clinicians to optimize management for these patients.

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.

High Grade Dermatologic Adverse Events Associated With Immune Checkpoint Blockade for Cancer

Immune checkpoint blockade (ICB) improves survival in many types of cancers including melanoma, non-small cell lung, renal cell, breast, and cervical cancers. However, many of these therapies are also associated with high grade dermatologic adverse events (DAEs), including Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN), SJS/TEN-like reactions, high grade maculopapular and psoriasiform rashes, autoimmune bullous eruptions, drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP), which may limit their tolerability and use. It is important to properly identify and treat DAEs to ICB because these DAEs may be associated with positive anti-tumor response and patients may have limited options for alternative anti-cancer therapeutics. In this review, we describe high grade DAEs to increasingly used ICB agents, which target CTLA-4 and PD-1 or its ligand, PD-L1 and enable the immune system to target cancer cells. We further differentiate life-threatening adverse reactions from mimickers and report cases of serious DAEs which have been recorded in association with ICB through the FDA Adverse Events Reporting System (FAERS), which is an archive of adverse events associated with various drugs and therapeutic biologic products reported voluntarily by consumers and healthcare professionals as well as mandatorily by manufacturers. Lastly, we summarize management recommendations for these adverse events and discuss knowledge and evidence gaps in this area.