Grover Disease Associated With Chemotherapy: Review of Potential Pathophysiology, Current Treatments, and Future Directions.

INTRODUCTION: Transient acantholytic dermatosis has been frequently reported in patients with malignancies. While paraneoplastic cases have rarely been reported, most eruptions occur in the setting of chemotherapeutic agents. Management is based on limited data and primarily with topical steroids and topical emollients. A subset of patients exhibits recalcitrant disease and require alternate therapeutic approachesMethods: This systematic review consisted of identifying records in PubMed using the medical subject headings (MeSH) terms “chemotherapy” AND “Grover”, “chemotherapy” AND “Grover’s”, “cancer” AND “Grover”, “cancer” AND “Grover’s”, “malignancy” AND “Grover”, “malignancy” AND “Grover’s”, as well as a free text search for “Grover” OR “Grover’s” OR “Grover disease” OR “Grovers disease” OR “Grover’s disease” OR “transient acantholytic dermatosis” OR “transient acantholytic” to identify case reports, case series, systematic reviews, review articles, meta-analyses, clinical trials, brief commentaries, and original articles. The titles and abstracts of all results were reviewed. Full texts of relevant results were then read in their entirety and applicability was determined. RESULTS: Overall, Grover disease has rarely been reported in the setting of malignancy. When it occurs, it is generally in the setting of chemotherapy use. Chemotherapy-associated Grover disease is reported most frequently in association with cytotoxic chemotherapies, followed by small molecule inhibitors. The first line treatment for this complication is the use of topical agents. When these provide inadequate relief, alternate therapies have been rarely reported, with novel treatments proposed based on the type of chemotherapy agent and its mechanism of action. CONCLUSIONS: Chemotherapy-associated Grover disease is an uncommon complication of cancer treatment. While most cases of chemotherapy-associated Grover disease can be treated with topical steroids and topical emollients, certain cases require a more specialized approach. This could include adjuvant adjuvant therapies, or novel treatments that are directly related to the mechanism of action of the chemotherapy involved. J Drugs Dermatol. 2020;19(11):1056-1064. doi:10.36849/JDD.2020.5648.

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.

BRAF inhibitor and hairy cell leukemia-related transient acantholytic dermatosis.

Grover disease (GD) is an acquired, nonfamilial, nonimmune mediated, transient or persistent acantholytic dermatosis. Herein, we present a 72-year-old man who had clinical and histopathologic findings of GD following two weeks of treatment with vemurafenib without MEK inhibitor. The patient was successfully treated with topical emollients and a high-potency corticosteroid. Meanwhile, vemurafenib was temporarily discontinued. Drug-induced GD has increasingly been reported in patients on BRAF inhibitor monotherapy as an immune-related adverse event. The cutaneous side effects seem to arise secondary to a paradoxical activation of the mitogen-activated protein kinase signaling of BRAF inhibitor treatment, leading to keratinocyte proliferation. Although the pathogenesis of GD has not been delineated, there is suggestion of activation of T lymphocytes, particularly helper cells under the action of pro-inflammatory cytokines, resulting in proliferation of keratinocytes. Combination therapy with a MEK inhibitor appears to prevent BRAF-induced GD. Given that there is a higher prevalence of GD in patients with hematologic malignancy, a direct causal relationship between the initiation of vemurafenib therapy and development of GD in this case may be difficult to establish.

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.

Role of Immune Status in Chemotherapy-Induced Transient Acantholytic Dermatosis.

A 79-year-old man with a recent diagnosis of acute myeloblastic leukemia received induction chemotherapy with daunorubicin and cytarabine, plus moxifloxacin and fluconazole prophylaxis. Approximately 2 weeks later, an asymptomatic eruption appeared on his trunk. He then developed a neutropenic fever and was started on aztreonam, vancomycin, voriconazole, and amikacin and was transferred to our facility from an outside hospital. Micafungin was subsequently added, and the patient defervesced within a few days.

PD-1 inhibitor-associated lichenoid inflammation with incidental suprabasilar acantholysis or vesiculation-Report of 4 cases.

BACKGROUND: Immune checkpoint agents targeting programmed cell death-1 protein (PD1) or cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) receptors are increasingly utilized in treatment of advanced malignancies. However, these immunotherapies are commonly associated with idiosyncratic cutaneous adverse reactions. Thus, recognition and awareness of these reactions are necessary. METHODS: We reviewed the skin biopsies of all patients on anti-PD1 therapy with or without ipilimumab who developed lichenoid inflammation and included those with microscopic suprabasal or intraepidermal clefts. RESULTS: Four patients presented with interface dermatitis with microscopic intraepidermal clefts. In 2 patients, the clefts were well developed and had some acantholytic cells while the other 2 appeared to be spongiosis or inflammation related. Immunofluorescence was negative in 1 patient. None of them had clinical findings in keeping with paraneoplastic pemphigus (PP) and the symptoms improved with either topical corticosteroid or withdrawal of immunotherapy. CONCLUSIONS: Lichenoid drug reaction occurring in patients receiving anti-PD1 therapy may be associated with microscopic suprabasal or intraepidermal clefting. The clinical course was similar to lichenoid drug reactions without clefting even though some lesions may resemble PP microscopically.

[Acantholytic dermatosis in patients treated by vemurafenib: 2 cases]. / Deux cas de dermatose acantholytique sous vémurafénib.

BACKGROUND: Acantholytic dyskeratosis under BRAF inhibitors are dermatological diseases rarely reported to date. PATIENTS AND METHODS: We report 2 cases of acantholytic dyskeratosis, reaching the trunk and the seborrheic zones, not itchy, appeared one month after the introduction of vemurafenib. The histological analysis was typical of a "Grover-like rash" for the 2 patients. DISCUSSION: The appearance of acantholytic dyskeratosis under vemurafenib, a BRAF inhibitor, seems related with a paradoxical activation of the MAP-kinases pathway and with a growth acceleration of lesions in which RAS mutations of keratinocytes. Theses dermatoses seem also to occur with dabrafenib. CONCLUSION: The patients treated by BRAF inhibitors (vemurafenib and dabrafenib) can present acantholytic dyskeratosis. The arisen of this mild dermatosis does not question, of course, the continuation of the treatment. These cutaneous manifestations can be managed with emollients.

Drug-related pityriasis rubra pilaris with acantholysis.

INTRODUCTION: Acantholysis is rarely reported histological feature of Pityriasis rubra pilaris (PRP), recently recognized as having diagnostic specificity for differentiating PRP from psoriasis. CASE REPORT: Adult male patient one week after the introduction of simvastatin had experienced pruritic erythemo-squamous eruption on head and upper trunk that in a month progressed to erythrodermia, with islands of sparing. Histological picture combined pemphigus-like acantholysis with alternating hyper- and parakeratosis, follicular plugs and dermal inflammation, and confirmed the clinical diagnosis of classic adult type 1 PRP. Acitretin therapy resulted in a resolution of skin disease. Patch test with simvastatin was negative, scratch test was positive, and it was estimated that potential risk of oral challenge with simvastatin outweighed actual need for it. Drug triggering PRP episode is the most likely explanation for temporal relation between the start of simvastatin treatment and skin eruption. CONCLUSION: In management of rare inflammatory skin disease, such as PRP, we have to carefully observe and evaluate not only diagnostic features but possible external influences on its course also.

[D-penicillamine-induced pemphigus: changes in anti-32-2B immunostaining patterns]. / Autonomisation d'un pemphigus induit par la D-pénicillamine: évolution de l'immunomarquage par l'anticorps anti-32-2B.

BACKGROUND: It has been reported that D-penicillamine causes pemphigus that is typically superficial. Immunostaining with monoclonal anti-32-2B antibody targeting desmoglein 1 and 3 can help differentiate between drug-induced and classical auto-immune pemphigus. Absence of specific staining militates in favour of drug-induced pemphigus whilst positive staining suggests an auto-immune aetiology that is ongoing despite discontinuation of drug therapy. PATIENTS AND METHODS: A 59-year-old male patient was referred for management of superficial pemphigus 1 year after starting D-penicillamine treatment for scleroderma. The diagnosis of pemphigus was confirmed histologically (intra-epidermal cleavage, acantholysis and perikeratinocytes, deposition of IgG and complement C3). Immunochemical staining with anti-32-2B antibody was initially normal, in keeping with drug-induced pemphigus. Despite discontinuation of D-penicillamine, pemphigus recurred in 2008. A further skin biopsy was undertaken and anti-32-2B staining was abnormal, which is consistent with auto-immune pemphigus. DISCUSSION: Numerous cases of drug-induced pemphigus have been described in the literature. In approximately half of all cases, the pemphigus recedes after cessation of the causative drug. However, there have been no previous reports that changes over time in the immunostaining with anti-32-2B antibodies can mirror a change in form of pemphigus from a drug-induced type to an idiopathic type as well as the associated clinical feature of persistence after drug withdrawal. CONCLUSION: Normal staining with anti-32-2B antibody is associated with a favourable prognosis as regards resolution of drug-induced pemphigus. When, as in this case, status changes to abnormal staining, there is a risk that the pemphigus may become chronic despite discontinuation of therapy.

[Adverse skin reactions induced by BRAF inhibitors: a systematic review]. / Effets indésirables cutanés des inhibiteurs de BRAF: revue systématique.

Recent developments and therapeutic use of selective BRAF inhibitors (e.g. dabrafenib and vemurafenib) have significantly improved overall survival and disease-free survival of patients with BRAF V600 mutation-positive metastatic melanoma. Despite their survival benefits, small-molecule inhibitors of BRAF are associated with significant and sometimes severe treatment-related dermatological toxicity. The most common adverse skin reactions include photosensitivity, induced malignant lesions of the skin such as keratoacanthomas, squamous cell carcinoma and new primary melanomas, as well as keratinocyte proliferation and differentiation dysfunctions that can manifest as skin papillomas, hand-foot skin reaction, keratosis pilaris-like rash, acantholytic dyskeratosis and cysts of the milia type. In this article, we describe the clinical and histological features of the cutaneous manifestations induced by vemurafenib and dabrafenib on the basis of our clinical experience and a literature review. The crucial role of dermatologists in patient management is also highlighted.

Cutaneous toxicities of RAF inhibitors.

The RAF inhibitors vemurafenib and dabrafenib are emerging as the standard of care for Val600 BRAF-mutant metastatic melanoma. These drugs have shown clinical benefit over the standard care (dacarbazine); however, they are associated with frequent cutaneous adverse events, which can be concerning to the patient and their physician. Herein, we review the range of cutaneous disorders that seem to be induced by RAF inhibitors, including cutaneous squamous-cell carcinoma, hyperkeratotic lesions, Grover's disease, keratosis pilaris-like reactions, and photosensitivity. These disorders often affect patients' quality of life; therefore, dermatological assessment and timely management is essential to ensure that patients continue to use RAF inhibitors.