Herpes zoster granulomatous dermatitis: histopathologic findings in a case series

Postherpetic granulomatous dermatitis occurring in the setting of immune checkpoint inhibitor therapy: A case report

We report a case of a 72-year-old man presenting with a 2-month history of a persistent, painful rash of the chest, axilla, and back. He had a history of recently resolved varicella zoster virus reactivation in the same distribution of the current rash and metastatic malignant melanoma treated with nivolumab and ipilimumab. The histopathology was consistent with granulomatous dermatitis (GD), and a diagnosis of postherpetic isotopic response manifesting as GD was made. Given the paucity of reported cases of postherpetic GD in the setting of treatment with immune checkpoint inhibitors (ICIs), we discuss the clinicopathologic features of this case and potential mechanisms by which ICIs may contribute to the development of granulomatous disease.

A Case of Herpes Zoster Granulomatous Dermatitis: Report of Wolf's Isotopic Response

Wolf's isotopic response refers to the occurrence of a novel skin disease at the site of a preceding treated or untreated skin disease. Although the most common preceding skin disease was found to be herpes zoster (HZ), HZ-related dermatological phenomena are not well known in the literature. We report a case of HZ granulomatous dermatitis in a 77-year-old female with a previous history of hypertension, diabetes mellitus, chronic kidney disease, and HZ. She presented with a 3-month history of a pruritic skin lesion on her right thigh. The location of the lesion was consistent with a previous HZ site. Histopathological examination revealed lympho- histiocytic infiltration in the superficial dermis, forming a granulomatous structure. Based on clinical and histopathological findings, we made a diagnosis of granulomatous dermatitis at a previous HZ site. We assumed that the lesion arose from an isotopic response of Wolf. The patient was treated with topical steroids for 3 months and showed clearance of the lesion and symptom. We suggest that treatment should be based on the individual disease, which in our case was topical steroid.

Spectrum of Clinicopathologic Findings in COVID-19-induced Skin Lesions: Demonstration of Direct Viral Infection of the Endothelial Cells

The novel coronavirus disease (COVID-19) is a rapidly spreading pandemic, secondary to severe acute respiratory syndrome coronavirus 2. The severity and the little knowledge that we have of the disease have made us focus mostly on the respiratory symptoms. As we bend the curve, other findings reported in association with COVID-19 become of importance for specialists to recognize. We describe the spectrum of clinicopathologic lesions in the skin that can be the only symptom or the first manifestation of COVID-19 and demonstrate the origin of the virus. We collected 25 patients with skin lesions in this context. We recognized 5 types of cutaneous manifestations including acute acroischemic or chilblain-like lesions (11), purpura palpable (2), exanthemas (9), urticarial eruptions (1), and other lesions (2) that might appear with more unspecific pictures. Chilblain-like lesions were the most common form of presentation, which tend to appear as self-healing, erythematous-necrotic plaques mostly on the feet, in young patients with no systemic symptoms associated. Importantly, we visualized viral particles with electron microscopy in 5 of 13 cases analyzed. In this study, we seek to draw a picture of the spectrum of clinicopathologic lesions that may appear in the skin in the context of COVID-19. Although apparently skin lesions are not correlated with disease severity, it may help in some cases to recognize and control the spread of the infection sooner.

Histopathologic features of noninfectious granulomatous disorders involving the skin

Granulomatous dermatoses may represent primary skin inflammation or can serve as the harbinger of a multitude of underlying systemic disorders or drug reactions. Taken together with clinical findings, the microscopic features from skin biopsy can allow recognition of various patterns and facilitate a precise diagnosis. Accurate classification of entities in this category of inflammatory dermatoses may prompt clinicians to investigate for underlying systemic problems, thereby allowing the pathologist to add considerable value in the care of affected patients. This review article categorizes clinical and microscopic features of common and uncommon causes of noninfectious dermal and subcutaneous granulomatous inflammation.

Herpes zoster granulomatous dermatitis in metastatic lung cancer treated with nivolumab: A case report

Granulomatous dermatitis (GD) is the most common among a variety of skin reactions that may occur in the varicella‐zoster virus (VZV) reactivation area. It is thought that the formation of granulomas may be the result of a delayed hypersensitivity reaction to viral envelope glycoproteins. Immune checkpoint inhibitors (ICIs), such as nivolumab stimulate T cells and promote hypersensitivity reactions, leading to the formation of granulomas in VZV wrapping proteins, thus triggering VZV‐GD. Few cases of the use of ICIs in patients diagnosed with VZV‐GD have been reported in the literature. Here, we report the clinical case of a patient with metastatic lung cancer which was treated with nivolumab who subsequently developed VZV‐GD. Accurate clinical diagnosis and prompt treatment with antiviral agents have resulted in a complete resolution of the clinical picture.

Key points

What this study adds

Few cases of ICI and VZV reactivation have been reported in the literature.

Full and timely resolution of VZV‐GD allowed the continuation of ICI treatment.

Herpes Zoster in the Older Adult

Herpes zoster (HZ) is the result of reactivation of latent varicella zoster virus (VZV) and occurs most frequently in older adults. Classically, HZ presents as a unilateral, selflimited, dermatomal rash. Postherpetic neuralgia (PHN) is a common sequela, presenting as severe pain that persists after the rash has resolved. In the elderly, PHN can be debilitating and requires a prompt diagnosis, treatment with antivirals, and adequate pain control. A longer-term pain management strategy is required if PHN occurs. A modestly effective vaccine exists and is recommended for older individuals.

Chronic granulomatous dermatitis induced by talimogene laherparepvec therapy of melanoma metastases

Talimogene laherparepvec (TVEC) is the first oncolytic viral immunotherapy approved by the FDA, for advanced melanoma consisting of genetically modified herpes simplex type 1 virus which selectively replicates causing tumor lysis, expressing granulocyte macrophage-colony stimulating factor (GM-CSF) and activating dendritic cells. Intratumoral injection of TVEC produces objective response in 41% of stage IIB-IV M1a melanoma. However, clinical response assessment can be problematic due to immune-related inflammation at established tumor sites. Herein, we report 5 cases of granulomatous dermatitis developing at sites of TVEC injection associated with pathologic complete response in 4 of 5 patients. Over 5 months, TVEC injections were administrated in a median of 20 tumors per patient for 9 median doses prior to biopsy of persistent, indurated nodules. Granulomatous dermatitis with melanophages and melanin pigment incontinence was observed in all samples without evidence of melanoma cells in 4 patients. The fifth patient was rendered melanoma-free by resection of the 1 nodule out of 4 with persistent tumor. Repetitive administration of TVEC or other oncolytic viral immunotherapies mimicking unresolved infection can produce granulomatous inflammation confounding assessment of the degree of tumor response and need for additional TVEC therapy. Tumor biopsies are encouraged after 4 to 6 months of TVEC administration to differentiate melanoma from granulomatous inflammation. Patients with confirmed granulomatous dermatitis replace continued with remained in remission after treatment discontinuation. Inflammatory nodules typically regress spontaneously.

Cutaneous involvement of pre-existing Rosai-Dorfman disease via post-herpetic isotopic response

We report the case of a patient with a long-standing history of extranodal, sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) and no evidence of original cutaneous involvement as well as a history of herpes zoster of the left flank with post-herpetic neuralgia who went on to develop multiple, round-to-oval, red-brown, atrophic macules and thin papules at the sites of herpes zoster scars on the left flank. Histopathology showed a dense nodular infiltrate of lymphocytes with some plasma cells and numerous large pale-staining histiocytes (S100+/CD68+), consistent with Rosai-Dorfman disease. This case showed exclusively cutaneous involvement, as demonstrated by otherwise normal physical examination, laboratory evaluation and imaging. This is the second reported case of Rosai-Dorfman disease occurring at the site of zoster scars, and to our knowledge this represents the first case report of cutaneous involvement of pre-existing Rosai-Dorfman disease via post-herpetic isotopic response (Wolf's isotopic response).