Lichen Sclerosus of the Labial Mucosa: A Case Report and Literature Review.

Lichen sclerosus (LS) is an uncommon, chronic, inflammatory mucocutaneous disorder found predominantly in females with unknown etiology. It presents as a white sclerotic plaque commonly located on the anogenital area. Extragenital LS is less prevalent, and LS affecting the oral mucosa is extremely rare, with only 39 biopsy-confirmed cases reported in the literature. Due to its several mimicking conditions, histological examination is usually required for a definitive diagnosis, particularly in patients with oral LS. Current evidence-based treatment recommendations for oral LS are unavailable; however, most cases tend to improve after treatment with topical or intralesional corticosteroids. We report a case of a 58-year-old female referred from the otolaryngology department for evaluating an asymptomatic whitish sclerotic plaque on the lower lip mucosa that had existed for 1 year. Following a punch biopsy, the patient was diagnosed with LS of labial mucosa. The condition improved after 2 months of treatment with topical and intralesional corticosteroids. The present case report raises awareness in recognizing oral LS and contributes to knowledge of this rare disorder.

Giant cell lichenoid dermatitis within healed varicella zoster site.

There are dermatoses that arise within healed zosteriform sites, such as granulomas annulare, acneiform eruptions, psoriasis, lichen planus, and giant cell lichenoid dermatitis "GCLD." Nonetheless, graft-versus-host disease should be considered and ruled out, especially in patients post-bone marrow transplant. Herein, we report a case of GCLD manifesting within healed zosteriform sites.

Lichenoid dermatitis following PD-1 inhibitor-induced toxic epidermal necrolysis: a case report and literature review.

Immune checkpoint inhibitors such as anti-PD-1 receptor antibodies have been shown to be effective in patients with advanced gastric cancer. However, there is a growing concern about immune-related adverse events. A case of a patient with gastric adenocarcinoma who developed toxic epidermal necrolysis (TEN) induced by sintilimab and subsequently developed lichenoid dermatitis is reported. TEN was diagnosed according to a history of sintilimab use, clinical symptoms and physical examination. During hospitalization, the patient developed recurrent fever caused by bacteremia and recovered from TEN after anti-infection and anti-inflammatory treatments. However, when TEN was controlled, the patient developed the lesional manifestations of lichenoid dermatitis. To date, no cases of lichenoid dermatitis after TEN have been reported following the use of PD-1 inhibitors.

PD-1 inhibitors are drugs that help fight stomach cancer but can sometimes cause skin problems. Most skin problems are minor and do not have a serious impact on the patient's health. However, life-threatening skin problems such as toxic epidermal necrolysis (TEN) can sometimes happen. This case report describes a patient with stomach cancer who had lichenoid dermatitis (another skin problem) after TEN, following the treatment of his cancer with PD-1 inhibitors. To the best of our knowledge, it is very rare to experience both skin problems after treating cancer with PD-1 inhibitors. This rare phenomenon is reported to bring more attention to it. More research is needed to determine how to treat this problem better.

Lichenoid drug eruption associated with imatinib mesylate therapy.

INTRODUCTION: Imatinib Mesylate (IM), a tyrosine kinase inhibitor, has been reported to cause several adverse reactions, most of them with cutaneous involvement. Non- Lichenoid IM associated skin reactions have been sufficiently- recorded. To our knowledge, Lichenoid Drug Eruption (LDE) is recorded in a minority of registries. CASE REPORT: To describe an LDE induced case by IM treatment. TREATMENT AND OUTCOME: Histological Confirmation and promptly dermatological consultation relieved successfully the cutaneous adverse event. DISCUSSION: Ongoing expansion of IM usage in a wide spectrum of new indications is more likely to make physicians experience such LDE cutaneous side effects more often. Hence, they should be highly suspicious to early detect these distinct histologic entities, handle these undesired complications and guarantee satisfactory immediate outcomes, avoiding frivolous IM dosage modifications.

Occult squamous cell carcinoma within lichenoid dermatitis: three examples of cryptic cancer detection.

Lichenoid dermatitis can be a perplexing entity encompassing an array of cutaneous disorders. Two hundred forty-three (243) cases of otherwise unclassifiable lichenoid dermatitis were examined histologically employing a special cytokeratin stain. Occult squamous cell carcinoma was detected in three of the 243 cases, uncovered by special immunohistochemistry staining within histologic specimens of lichenoid dermatitis. We recommend staining for cutaneous cancer becoming a routine practice in evaluating cutaneous lichenoid dermatitis.

Uncommon Non-Infectious Annular Dermatoses.

Several cutaneous diseases can present with annular lesions, making a distinction by physical appearance alone challenging. They can be distinguished into infectious and non-infectious, and common and uncommon annular dermatoses. Common non-infectious diseases include granuloma annulare, urticaria, and subacute lupus erythematosus. In addition, there are rare non-infectious non-neoplastic annular dermatoses whose nosographic attribution is established, including annually recurring erythema annulare centrifugum (EAC) and annular erythema in Sjögren syndrome and others whose nosographic positioning is still debated. They are neutrophilic figurate erythema, palpable migratory arciform erythema, eosinophilic annular erythema, and annular lichenoid dermatitis of youth. Their etiopathogenesis is largely unknown, although immune-mediated mechanisms are likely involved. It is difficult to establish if they are variants of reaction patterns or separate clinic-pathological entities. In fact, EAC and annually recurring EAC may represent different aspects of the same disease. Palpable migratory arciform erythema is hardly distinguishable from EAC deep type, Jessner-Kanof disease, and lupus tumidus. Neutrophilic figurate erythema and eosinophilic figurate erythema are clinically very similar and differing only in the relative proportion of eosinophils and neutrophils.

Pembrolizumab-Induced Lichenoid Dermatitis in a Patient With Metastatic Cancer of Unknown Primary.

Pembrolizumab is an immune checkpoint inhibitor approved for use in many cancer types such as non-small cell lung cancer (NSCLC), metastatic melanoma, head and neck cancers, hepatocellular carcinoma, and renal cell carcinoma. There are many reported cases of patients on immunotherapy who have discontinued treatment due to the development of immune-related adverse effects (irAE). Recognition of the histopathologic patterns of dermatologic toxicities due to immunotherapy will become increasingly important for ensuring appropriate management and optimal patient care. Here, we present a case of a 72-year-old man with metastatic carcinoma of unknown primary origin treated with pembrolizumab who developed an immune-related cutaneous adverse event (ircAE) in the form of lichenoid dermatitis.

Erythema ab igne with features resembling keratosis lichenoides chronica.

Erythema ab igne (EAI) is an asymptomatic dermatosis that develops in response to chronic exposure to low-grade heat. Characteristic findings on histopathology include epidermal atrophy, dermal elastosis, atypical histiocytes, and melanin and hemosiderin deposition. Reactive endothelial changes and prominent vascular proliferation are variable. Keratosis lichenoides chronica (KLC) is a rare lichenoid hyperkeratotic dermatosis. Acanthosis with parakeratosis and a lichenoid interface dermatitis with lymphocytes, histiocytes, and plasma cells are characteristic findings of KLC. Although its etiology remains unclear, KLC has been reported to occur in response to heat. Herein, we report a case of EAI with features resembling KLC.

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.

Hypertrophic lichenoid dermatitis immune-related adverse event during combined immune checkpoint and exportin inhibitor therapy: A diagnostic pitfall for superficially invasive squamous cell carcinoma.

Immune checkpoint inhibitors (ICIs) for cancer treatment have revolutionized the field of medicine. However, an unintended but frequent consequence of ICI therapy is the development of cutaneous immune-related adverse events (irAEs), such as lichenoid dermatitis irAEs (LD-irAEs). The hypertrophic variant of LD-irAE may be a diagnostic challenge since it can mimic superficially invasive squamous cell carcinoma (SCC). A 79-year-old woman with metastatic melanoma who began treatment with an ICI-pembrolizumab-plus exportin-1 (XPO1) inhibitor presented after 1 month of therapy with symmetrical violaceous papules coalescing into plaques and with two nodules of the bilateral dorsal hands. Biopsy of the nodules revealed an actinic keratosis and atypical epidermal proliferation concerning for SCC. However, in the ensuing 3 weeks, the patient developed multiple new erythematous, violaceous, and scaly macules and papules, some coalescing into plaques on the extremities. Biopsies of these lesions revealed exuberant irregular epidermal hyperplasia with hypermaturation and lichenoid infiltrate concentrated at the base of the elongated, broadened rete ridges, consistent with hypertrophic LD-irAE. Treatment included topical fluocinonide ointment, intralesional triamcinolone injections and oral acitretin. Distinguishing hypertrophic LD-irAE and SCC can be challenging since both entities share histopathologic features; thus, correlation with clinical presentation is essential for diagnosis and optimal patient management.

Annular lichenoid dermatitis of youth-Recurrent case of rare skin disease treated with cyclosporine.

Annular lichenoid dermatitis of youth (ALDY), first described in 2003, represents an uncommon entity whose etiopathogenesis is still debated. Futhermore, the optimal treatment for ALDY is yet to be established. We report a 9-year-old girl who presented with annular and oval erythematous lesions mostly on her trunk, with several lesions on the neck, groin, flanks, and upper extremities. The lesions had histological and immunohistochemical features characteristic for ALDY. Treatment with H1-antihistamines, topical corticosteroid, and UVB therapy was unsuccessful, while systemic treatment with cyclosporine induced complete remission.

Lichen planopilaris induced by infliximab: A case report.

Infliximab is a tumor necrosis factor-alpha inhibitor used to treat a range of inflammatory diseases. Most reports of cutaneous eruptions from tumor necrosis factor-alpha inhibitors have described the paradoxical development of psoriasis or psoriasiform drug reaction. In our report, we present a 31-year-old female with inflammatory bowel disease who developed an unusual lichenoid drug reaction to infliximab involving the hair follicles, resulting in progressive global alopecia. Clinical features and histopathological findings were consistent with drug-induced lichen planopilaris with eosinophils and lichenoid dermatitis.

Lichenoid granulomatous dermatitis revisited: A retrospective case series.

BACKGROUND: Lichenoid granulomatous dermatitis (LGD) is an uncommon reaction pattern for which clinical correlates can be difficult to establish. LGD combines vacuolar degeneration with variable types of granulomas. OBJECTIVE: To determine clinical correlates of LGD. METHODS: The laboratory information systems at the University of Florida, the Medical College of Wisconsin, and Inform Diagnostics Research Institute were queried to identify 56 cases of LGD. Cases were reviewed for information regarding eosinophils, plasma cells, deep perivascular infiltrates, granuloma subtype, parakeratosis, epidermal atrophy, psoriasiform epidermal changes, pseudoepitheliomatous hyperplasia, periadnexal inflammation, vasculitis, and red blood cell extravasation. RESULTS: The most common clinical correlates were drug eruption (39.3%, n = 22) and lichenoid keratosis (19.6%, n = 11). Tattoo reaction, postherpetic dermatitis, and scabies or postscabietic dermatitis each accounted for 7.1% (n = 4) of cases. Pigmented purpuric dermatosis and lichen striatus each accounted for 5.4% (n = 3) of cases. Dermal eosinophils (P = .005) and psoriasiform epidermal changes (P = .055) were associated with drug hypersensitivity. Perineural (P = .049) and perifollicular (P = .003) inflammation were associated with tattoo reaction and postherpetic dermatitis. Red blood cell extravasation was helpful in cases of pigmented purpuric dermatosis (P = .049). LIMITATIONS: This study is limited by its retrospective nature and statistical power. CONCLUSION: Dermal eosinophilia, psoriasiform epidermal changes, periadnexal inflammation, and red blood cell extravasation might aid in the clinical diagnosis of patients with LGD.

Lichenoid dermatitis from immune checkpoint inhibitor therapy: An immune-related adverse event with mycosis-fungoides-like morphologic and molecular features.

Cutaneous immune-related adverse events (irAEs) are a known consequence of immune checkpoint inhibitor (ICI) therapy and may exhibit a spectrum of morphologic features both clinically and histologically. Lichenoid dermatitis associated with ICI therapy (LD-ICI) is the most frequently encountered histopathologic type of irAE biopsied by dermatologists. There is frequent clinical and histologic overlap between irAEs and several reactive and neoplastic dermatologic disorders; thus, clinical information is essential. LD-ICI with histologic, immunohistochemical, and molecular features typical of mycosis fungoides (MF) are unique. Here, we report a patient who developed LD-ICI with MF-like morphologic features with monoclonal T-cell receptor gene rearrangement on consecutive biopsies during ICI therapy. The development of monoclonal LD-ICI is important for clinicians and pathologists to recognize in patients receiving ICI therapy.

Gene expression profiling of lichenoid dermatitis immune-related adverse event from immune checkpoint inhibitors reveals increased CD14+ and CD16+ monocytes driving an innate immune response.

BACKGROUND: Cancer patients receiving antibodies abrogating immune checkpoint pathways may develop a diverse array of immune-related adverse events (irAEs), of which lichenoid dermatitis (LD) is the most common. The mechanism driving the emergence of these irAEs remain understudied, underscoring a critical need to determine the unique gene expression profiles and immune composition in LD-irAE. METHODS: LD-irAE (n = 3) and benign lichenoid keratosis (BLK) control (n = 3) were profiled with NanoString nCounter PanCancer Immune Profiling Panel interrogating the mRNA levels of 770 genes. Immunohistochemical (IHC) studies (n = 14 samples) for CD14, CD16, T-Bet, Gata-3, and FoxP3 were further evaluated using Aperio digital image analysis. RESULTS: The LD-irAE showed downregulation of 93 mRNA transcripts (P < 0.05) and upregulation of 74 mRNA transcripts (P < 0.04) including toll-like receptor (TLR) 2 and TLR4 (P < 0.05). CD14+ and CD16+ monocytes quantified by IHC (H-score) were higher in LD-irAE than in the BLK control (P < 0.05). The immune composition of LD-irAE exhibited higher numbers of T-Bet+ (Th1) cells compared with Gata-3+ (Th2) cells (P = 0.016) and lower numbers of FoxP3 (T regulatory) cells (P = 0.008). CONCLUSIONS: LD-irAE exhibited activation of CD14/TLR innate immune response with increased CD14+ and CD16+ monocytes compared with BLK control. CD14/TLR signaling may drive the development of LD-irAE.

[Annular lichenoid dermatitis of youth: A case report and literature review]. / Dermatite lichénoïde annulaire du sujet jeune : un cas et revue de la littérature.

BACKGROUND: Annular lichenoid dermatitis of youth (ALDY) is a rare form of dermatitis mainly affecting children and young people. All cases reported show a consistent clinical and histological picture. This is the first case described in the French literature. PATIENTS AND METHODS: A 5-year-old girl presented an annular isolated patch of the lower abdomen with an erythematosquamous border and central hypopigmentation for one year. Topical corticosteroids and pimecrolimus proved effective but relapse occurred after treatment withdrawal. DISCUSSION: Over sixty cases of ALDY are described in the English-language medical literature. The main differential diagnosis is childhood mycosis fungoides, particularly the hypopigmented variant. Biopsy is necessary for diagnosis since it can reveal typical histological features. Histopathology in all cases shows lichenoid reaction with CD4+ and CD8+ polyclonal lymphocytes. It is limited to the tips of rete ridges and associated with apoptosis of keratinocytes resulting in quadrangular-shaped rete ridges. Our case does not demonstrate either epidermotropism or atypical lymphocytes. CONCLUSION: Annular lichenoid dermatitis of youth (ALDY) is a poorly known distinctive entity within the lichenoid dermatitis family. Clinical-histological correlation is essential to diagnosis. The etiology is still unknown and the course is mostly chronic.