Cutaneous reactions at sites of herpes zoster scars: an expanded spectrum

Approach to the so-called "Invisible Dermatosis": When Subtle Histopathological Findings Guide Diagnosis

ABSTRACT

Invisible dermatosis is a concept that can be applied either to clinical or histopathological findings. We will focus on the dermatopathological aspect of this invisible dermatosis that can be seen as dermatosis with subtle histopathological findings that are mandatory to known to stablish the diagnosis. With a proper approach facing in depth the different skin layers from stratum corneum to subcutaneous tissue combined with some especial stains, special investigations and mostly a proper clinicopathological correlation, the problem of missing out a diagnosis can be decreased. We will review the general aspects for diagnosis and the peculiar findings of an in-depth review of them because it is important to note that minor changes on a skin biopsy do not mean it is disease free. We will review classic clues, we will add some new useful ones, and we will also provide a guide on the special stains helpful, such as periodic acid-Schiff when facing fungi, orcein-Giemsa and van Gieson when altered elastic fibers are suspected, or Pearl and Masson Fontana when an altered skin pigmentation is suspected.

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.

Lichen Planus

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

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.

Incidence of and Risk Factors for Cutaneous Scarring after Herpes Zoster

BACKGROUND

About 20% of children have cutaneous scars following chickenpox. In contrast, skin scars are not often reported after herpes zoster (HZ). Risk factors for post-HZ scarring remain undetermined.

OBJECTIVE

Our objective was to prospectively study the incidence of and risk factors for post-HZ scarring.

METHODS

This was a 3-year prospective study of patients with HZ attending a tertiary university hospital. Baseline data, including age, sex, immunosuppression, prior history of scarring, severity and extension of HZ, afflicted HZ dermatome, and antiviral treatment received, were recorded. At 1 month after the HZ skin lesions had healed, patients were screened for skin scars at the prior HZ site. These patients were followed every 2 months for 6 months.

RESULTS

At 6 months, 11 (9.7%) of 113 HZ patients still had post-HZ scarring (fair-skinned patients: hypopigmented [n = 3], hyperpigmented [n = 2], atrophic cicatricial [n = 3], and hypertrophic cicatricial [n = 1]; dark-skinned patients: severe hyperpigmented hypertrophic scarring [n = 2]). HZ was extensive and severe in all cases. Nine of the 11 patients were immunocompromised. Three cases had a history of hypertrophic/keloid scarring but no post-varicella scars. The most frequent location was the trunk (n = 5), followed by the cervical region (n = 3) and the face (n = 3). Given the study setting, it is possible that immunocompromized patients with severe HZ were overrepresented in this study.

CONCLUSIONS

Scarring after HZ is probably overlooked. The principal risk factors seem to be severe HZ and immunosuppression. Hence, prompt instigation of antiviral treatment for HZ and HZ vaccination could help reduce the incidence of post-HZ scarring.

Mycosis fungoides occurring at the site of previous herpes zoster eruption

Numerous clinicopathological variants of mycosis fungoides have been described in the literature. Dermatomal or zosteriform mycosis fungoides is one reported variant but a clear aetiology has never been documented. We report a case of mycosis fungoides proved by biopsy and immunohistochemistry that developed in a 55-year-old man at the site of previous herpes zoster eruption. We also present a review of the relevant literature to add to the understanding of rare variants of mycosis fungoides and aid in the clinical recognition of zosteriform mycosis fungoides.

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).

Herpes zoster granulomatous dermatitis: histopathologic findings in a case series

Several types of cutaneous reactions have been reported to arise at the site of herpes zoster (HZ) infection weeks to years after the acute disease. Among these, granulomatous reactions are the most frequently reported. In this study, we describe the spectrum of histopathologic findings of HZ granulomatous reactions observed in 26 patients with cutaneous lesions confined to the area of previous HZ eruption and compare them with biopsy specimens taken from 25 patients with acute HZ. All patients with persistent reactions from whom history was available presented within 12 weeks of the onset of the acute eruption. The most frequent findings were interstitial granulomatous dermatitis with lymphocytes, histiocytes and multinucleated giant cells displaying elastophagocytosis and a perineural, perivascular and perieccrine mononuclear inflammatory infiltrate rich in lymphocytes and plasma cells. Less common features included intra-arrector and peri-arrector pili granulomas, follicular dilatation and hyperkeratosis, and vasculitis. Specimens from patients with acute HZ were found to have small numbers of perineural plasma cells and most had subtle granulomatous inflammation, in patterns similar to the group with late granulomatous reactions. Our findings suggest that granulomatous reactions to varicella zoster virus represent a persistent evolving inflammatory reaction after acute infection.

Granulomatous dysimmune reactions (sarcoidosis, granuloma annulare, and others) on differently injured skin areas

Granulomatous disorders are chronic cell-mediated immune responses histologically characterized by collections of macrophages, epithelioid cells, and multinucleated giant cells. This disease spectrum often has an infectious origin, but sometimes neither an infective agent nor an inciting antigenic stimulus can be identified. The skin may be a preferential target for these disorders, especially in the areas that have been damaged by various forms of skin injury (eg, herpetic infections, trauma, thermal or solar burns, vaccinations, tattoos). These damaged skin sites frame the new concept of an immunocompromised cutaneous district (ICD), which defines a skin area with acquired immune dysregulation that can pave the way for the local onset of opportunistic disorders, such as infections, tumors, and granulomatous disorders. Sarcoidosis, granuloma annulare (GA), and forms of granulomatous vasculitis, such as Churg-Strauss syndrome (CSS) and Wegener's granulomatosis (WG), are the most common granulomatous disorders that occur in an ICD and may share common pathogenic mechanisms. Recent studies have found clinical and pathologic overlapping features across noninfectious granulomas. Although no unifying etiology exists, the development of granulomatous processes in the ICD has often been reported and the literature contains various hypotheses to explain it: (1) overactive immune response in a previously injured region with or without loss of immune tolerance; (2) overall reduced immune response; (3) retention of an exogeneous antigen or foreign body; (4) altered neural signaling; and (5) a combination of all the aforementioned processes. T helper cells, T regulatory cells, and macrophages, as well as a number of antigenic proteins, have been identified as potential contributing factors. In addition, a genetic predisposition and an intact systemic immune system are both instrumental for the persistence of local granuloma formation in the ICD.

Wolf's post-herpetic isotopic response: Infections, tumors, and immune disorders arising on the site of healed herpetic infection

Herpes simplex viruses (HSV-1/HSV-2) and varicella-zoster virus (VZV) have several characteristics in common. Both are epidermoneurotropic, cause skin eruptions accompanied by sensory symptoms (itch, pain), damage peripheral sensory nerve fibers and cutaneous nerve endings, and interfere with neuromediator release, which can alter local mechanisms of immune control. For this reason, herpes-infected areas may become a preferential location for the subsequent onset of immunity-related skin disorders (infections, tumors, and dysimmune reactions), an event first reported by a neurologist and focused on by two brothers, a dermatologist and a pediatrician. The phenomenon therefore named Wolf's post-herpetic isotopic response (PHIR) refers to the occurrence of a new skin disorder at the site of a previous and already healed herpetic eruption (herpes zoster in most cases). Until now, we have been able to gather 189 well-documented cases of PHIR (all reported in the reference section), but our list is far from being complete. Some of the most emblematic cases are briefly described here. In some circumstances, the opposite of PHIR occurs, with diffuse skin disorders or eruptions that selectively spare herpes-infected areas (Wolf's post-herpetic isotopic nonresponse). Experimental investigations with patch testing have been performed in seven patients who were sensitized to nickel and had had herpes zoster in the past years. The tests were carried out bilaterally on the affected dermatomes and on the unaffected contralateral ones. The uneven immune responses we obtained have shown that the immune behavior of an herpes zoster-affected dermatome can be different from that of the corresponding contralateral dermatome, thus supporting the existence of immune dysregulation in herpes-infected areas.

Disseminated, persistent, and fatal infection due to the vaccine strain of varicella-zoster virus in an adult following stem cell transplantation

Live attenuated varicella vaccine is recommended for healthy individuals who are susceptible to varicella. Although the vaccine is safe, effective, and used worldwide, serious adverse events have been reported, mainly in immunocompromised patients who subsequently recovered. Here, we describe the fatality of an immunocompromised patient who received the varicella vaccine. His medical history provides a cautionary lens through which to view the decision of when vaccination is appropriate. A middle-aged man with non-Hodgkin lymphoma received chemotherapy and a stem cell transplant. He was vaccinated 4 years post-transplantation, despite diagnosis of a new low-grade lymphoma confined to the lymph nodes. Within 3 months of vaccination, he developed recurrent rashes with fever, malaise, weakness, hepatitis, weight loss, and renal failure. The syndrome was eventually determined to be associated with persistent disseminated zoster caused by the vaccine virus. This case illustrates a circumstance when a live viral vaccine should not be used.

Granuloma annulare as an isotopic response to herpes zoster

BACKGROUND

Wolf's isotopic response is the phenomenon of a new skin disease occurring at the site of another unrelated and already healed skin disorder. Most cases in the literature report herpes zoster (HZ) as the original disease; however, the isotopic responses vary greatly. Including this case, our literature search revealed 32 cases of isotopic granuloma annulare (GA) following HZ.

CASE REPORT

An 82-year-old male presented with GA localized to the right T9 dermatome that later appeared at other sites on the trunk and extremities. The patient had an episode of shingles involving the same dermatome 4 years earlier.

DISCUSSION

To our knowledge, this is the first case report of GA occurring initially as an isotopic response in an HZ scar and subsequently becoming generalized. Thirty-eight percent (12 of 32) of patients with isotopic GA following HZ were immunocompromised, which is similar to the published rate of immunodeficiency in patients with HZ.

Cutaneous cytomegalovirus infection on multi dermatomal herpes zoster scars: an isotopic immune response

As more patients with human immunodeficiency virus (HIV) are surviving, despite severe immune suppression, clinicians are faced with atypical manifestations of both common and uncommon dermatoses. A 30-year-old black South African woman presented with a 10-month history of multiple chronic ulcers appearing on a multidermatomal herpes zoster (HZ) scar. The woman was infected with HIV, and her CD4 count was 45 cells/μL. Histology and PCR revealed cytomegalovirus (CMV) infection. This case highlights an unusual presentation of cutaneous CMV occurring as an isotopic immune response on a pre-existing multidermatomal HZ scar.

Post herpes-zoster scar sarcoidosis with pulmonary involvement

Cutaneous sarcoidosis presents with a wide range of clinical presentations. An uncommon cutaneous manifestation is infiltration of old cutaneous scars with non-caseating granulomas known as scar sarcoidosis. Most of the patients with this clinical entity have other systemic manifestations, particularly pulmonary changes. We report a case of a 50 years old man, presenting with cutaneous sarcoidosis overlying scars of healed herpes zoster.

Churg-Strauss syndrome presenting as scar reactivation: histopathologic features and an illustration of 'locus minoris resistentiae'

We report a 33-year-old female with cutaneous involvement by Churg-Strauss syndrome confined to surgical scars that were obtained 13 years before. She presented to the emergency department with 2-day history of fever, night sweats, right-sided weakness, hoarseness and worsening asthma symptoms. She was found to have an eosinophilia and two sub-5-mm pulmonary nodules. The patient also reported that the scars on her right thumb, inner wrist and back had been swollen, red and painful for 2 days. Examination revealed tender, erythematous, well-healed edematous scars studded with small skin colored papules. She had no clinical findings that were classic for cutaneous vasculitis. A skin biopsy of a scar revealed perivascular and palisading granulomatous inflammation consisting of histiocytes and neutrophils with leukocytoclasia. Focal vascular injury was identified. Scattered tissue eosinophils were seen. Special stains were negative for infection. Thereafter, she was started on intravenous steroids, at which point the fever, pulmonary and cutaneous symptoms subsided. Although scar sarcoidosis is a well-described phenomenon, granulomatous inflammation and vasculitis seen in Churg-Strauss syndrome exclusively manifesting in well-healed surgical scars highlights the unique features seen in this case and draws attention to the concept of locus minoris resistentiae. This case also highlights how a skin biopsy in the setting of suspected systemic vasculitis can confirm the presence of vasculitis and/or granulomatous inflammation and obviate the need for more invasive, higher risk procedures such as lung biopsy.

Wolf Isotopic Response Manifesting as Postherpetic Granuloma Annulare: A Case Series

Context.— Wolf isotopic response has infrequently been reported in the literature, mainly as isolated case reports.

Objective.— To aid in recognition of the occurrence of postherpetic granuloma annulare for accurate histologic interpretation of granulomatous dermatitides.

Design.— We report 5 cases of patients with Wolf isotopic response manifesting as granuloma annulare, developing in a site of previous herpes zoster, and discuss the clinicopathologic findings.

Results.— Previous infection with herpes zoster or herpes simplex virus was found in 5 of 5 cases reported. The differential diagnosis of a dermal lymphohistiocytic infiltrate with multinucleated giant cells includes postherpetic granuloma annulare.

Conclusions.— All cases of postherpetic Wolf isotopic response reported in this series revealed granuloma annulare, with a perineurovascular or perifollicular pattern of lymphohistiocytic infiltration including multinucleated giant cells, and occurred following herpes zoster or herpes simplex infection, although herpes viral infection was not always associated with a subsequent isotopic eruption. Awareness of this entity can aid in the clinicopathologic diagnosis of granuloma annulare occurring at the site of prior herpes viral infection.

Coexistent granulomatous vasculitis and leukaemia cutis in a patient with resolving herpes zoster

An 80-year-old man presented with a 6-month history of indurated tender purple papules. These had coalesced to form plaques with some central scarring and a dermatomal distribution on the left arm, immediately following herpes zoster (HZ) infection at this site. The patient had a 5-year history of small lymphocytic lymphoma (SLL), which was being managed conservatively under a 'watch and wait' protocol. On histological examination of a skin biopsy, marked interstitial granulomas and prominent granulomatous vasculitis were seen, supporting the clinical impression of a post-HZ granulomatous reaction. In addition, there was a dense monoclonal small B-cell lymphocytic infiltrate indicating koebnerization by SLL (a finding that has not been reported previously with concurrent postherpetic granulomatous vasculitis). Although benign pseudolymphomas occur in postherpetic cases, this case shows that even in association with benign vasculitic features true lymphomas can occur. Furthermore, this case highlights the importance of immunocytochemistry, molecular studies and clinicopathological correlation.

Zosteriform morphea: Wolf's isotopic response in an immunocompetent patient

We report the case of a 19-year old female who presented to our dermatological clinic with hyperpigmented, indurated and atrophic patches on a zosteriform distribution, extending from her left submammary region through to her back. Our case was consistent with a zosteriform morphea as an expression of an isotopic Wolf response following an episode of herpes zoster. We discuss the pathogenic mechanisms and review the clinical cases previously reported in the literature.

Morphea developing at the site of healed herpes zoster

Wolf's isotopic response describes the occurrence of a new, unrelated disease that appears at the same location as a previously healed skin disease, and the most common primary skin disease of this phenomenon is herpes zoster. Several cutaneous lesions have been described to occur at the site of healed herpes zoster, and granulomatous dermatitis and granuloma annulare have been reported to be the most common second diseases. The pathogenesis of the isotopic response is still unclear. Morphea can develop at the site of regressed herpes zoster and a few such cases have been reported. We present here an additional case of morphea that developed at the site of previously healed herpes zoster, and we review the relevant literature.

Granulomatous skin lesions complicating Varicella infection in a patient with Rothmund-Thomson syndrome and immune deficiency: case report

Rothmund-Thomson syndrome (RTS)(OMIM 268400) is a rare autosomal recessive genodermatosis characterized by poikiloderma, small stature, skeletal and dental abnormalities, cataract and an increased risk of cancer. It is caused by mutations in RECQL4 at 8q24. Immune deficiency is not described as a classical feature of the disease. Here we report the appearance of granulomatous skin lesions complicating primary Varicella Zoster Virus infection in a toddler with Rothmund Thomson syndrome and immune deficiency. Although granulomatous disorders are sometimes seen after Herpes zoster, they are even more rare after Varicella primary infection. Granulomas have hitherto not been described in Rothmund-Thomson syndrome. With this report we aim to stress the importance of screening for immune deficiency in patients with Rothmund-Thomson syndrome.

A Case of Post-zoster Eosinophilic Dermatosis

Post-zoster eosinophilic dermatosis is a rare disease that occurs as an isotopic response in the region of previously healed herpes zoster. We report here on a case of post-zoster eosinophilic dermatosis that occurred 13 years after an episode of herpes zoster. A 48-year-old woman presented with several pruritic, brown papules and plaques in the same dermatome where her previous episode of herpes zoster had healed. Histopathologically, there was a dermal inflammatory cell infiltration composed of abundant eosinophils, lymphocytes and histiocytes. Based on these clinicopathologic findings, the patient was diagnosed with post-zoster eosinophilic dermatosis.

Childhood cutaneous lymphoid hyperplasia following feline scratches

Cutaneous lymphoid hyperplasia or pseudolymphoma is a usually benign inflammatory response that mimics lymphoma. Stimulation from foreign antigens introduced into the skin can induce this response. Scratches from pets are an effective mode of transmitting infections and inoculating foreign antigens into the skin. We report an unusual case of a child where cutaneous lymphoid hyperplasia presented as subcutaneous nodules at sites scratched by a pet cat.