A clinicopathological description of COVID-19-induced chilblains (COVID-toes) correlated with a published literature review.

BACKGROUND: The abundance of publications of COVID-19-induced chilblains has resulted in a confusing situation. METHODS: This is a prospective single-institution study from 15 March to 13 May 2020. Thirty-two patients received PCR nasopharyngeal swabs. Of these, 28 patients had a thoracic CT-scan, 31 patients had blood and urine examinations, 24 patients had skin biopsies including immunohistochemical and direct immunofluorescence studies, and four patients had electron microscopy. RESULTS: COVID-19-induced chilblains are clinically and histopathologically identical to chilblains from other causes. Although intravascular thrombi are sometimes observed, no patient had a systemic coagulopathy or severe clinical course. The exhaustive clinical, radiological, and laboratory work-up in this study ruled-out other primary and secondary causes. Electron microscopy revealed rare, probable viral particles whose core and spikes measured from 120 to 133 nm within endothelium and eccrine glands in two cases. CONCLUSION: This study provides further clinicopathologic evidence of COVID-19-related chilblains. Negative PCR and antibody tests do not rule-out infection. Chilblains represent a good prognosis, occurring later in the disease course. No systemic coagulopathy was identified in any patient. Patients presenting with acral lesions should be isolated, and chilblains should be distinguished from thrombotic lesions (livedo racemosa, retiform purpura, or ischemic acral necrosis).

Discordant anti-SARS-CoV-2 spike protein and RNA staining in cutaneous perniotic lesions suggests endothelial deposition of cleaved spike protein.

BACKGROUND: Prior studies have shown the presence of immunohistochemical staining for the SARS-CoV-2 spike protein (SP) in endothelial cells and eccrine epithelium of acral perniosis classified as "COVID toes." Yet, other studies have been unable to detect SARS-CoV-2 RNA in skin biopsies of "COVID toes" by reverse-transcriptase polymerase chain reaction testing. OBJECTIVE: In order to address these apparently conflicting findings, we compared detection of SARS-CoV-2 SP, through RNA in situ hybridization (ISH) vs immunohistochemistry (IHC), in skin biopsies of acral perniotic lesions presenting during the COVID-19 pandemic. RESULTS: Three of six cases showed positive immunohistochemical labeling of endothelial cells, with one of three cases with sufficient depth also having labeling of eccrine glands, using an anti-SP SARS-CoV-2 antibody. These three cases positive with IHC were negative for SP by RNA ISH. CONCLUSION: While the gold standard for detection of SARS-CoV-2 in tissue sections has yet to be determined, the detection of SARS-CoV-2 SP alone without spike RNA suggests that cleaved SP may be present in cutaneous endothelial cells and eccrine epithelium, providing a potential pathogenetic mechanism of COVID-19 endotheliitis.

Study of squamous cell carcinoma associated with syringofibroadenoma for 105 types of human papillomavirus and for all currently known types of polyomaviruses.

Syringofibroadenoma is a benign tumor of the eccrine glands. Few cases of association with squamous cell carcinoma (SCC) have been published in the literature. In one of them, infection by human papillomavirus (HPV) type-107 was detected and the authors postulated that the virus might play a carcinogenic role. We studied a case of syringofibroadenoma associated with an SCC on the back of the right hand of an immunocompetent 95-year-old man. The lesion showed strong diffuse cytoplasmic staining for cytokeratin (CK) AE1/AE3, CK5/6, and 34ßE12 in the areas of syringofibroadenoma and in the areas of SCC. The marker p63 was expressed by the lower two thirds of the epithelium of the syringofibroadenoma. Epithelial membrane antigen and CK18 were expressed only by the superficial layers of the syringofibroadenomatous epithelium. The carcinomatous areas were epithelial membrane antigen positive. MIB1, p16, and p53 were mainly expressed by the SCC areas. The lesion was negative for all mucosal and cutaneous genus α-HPV, and for cutaneous HPV from γ-, µ-, and ν-genera. In 3 repeated genotyping experiments analyzing DNA from 2 consecutive biopsy sections, ß-HPV-9, 20, 36, 47, and 75, as well as FA-22 and 51 were found only once in the 6 possible reactions. ß-HPV-8 and 96 were detected 2 and 4 times, respectively, indicating very low viral loads of these HPV types. None of 8 known polyomaviruses was identified. ß-globin positivity was present in each assay, confirming sufficient quality of analyzed DNA.

Syringitis: a clue to herpes infection.

Herpes simplex virus (HSV) is a member of the herpes virus family that commonly affects the skin. Typical histopathologic findings are usually limited to the epidermis and include intraepidermal vesicles or ulceration and epidermal necrosis. More specific findings in herpes virus infection include enlarged and pale keratinocytes, with steel-gray nuclei and margination of chromatin at the edge of the nucleus and ballooning degeneration. Although histopathologic changes may occasionally involve the hair follicles or sebaceous glands, it is very rare to find HSV involving the eccrine glands. We present a case of a 13-month-old child with a large body burn diagnosed with HSV (in the absence of the epidermis) by the presence of syringitis with herpetic features in the absence of the epidermis to aid in diagnosis.

Detection of varicella-zoster virus antigens in lesional skin of zosteriform lichen planus but not in that of linear lichen planus.

BACKGROUND: Distinctions between 'linear lichen planus' (LP) and 'zosteriform LP' are difficult to determine solely based on clinical findings. OBJECTIVE: The aim of this study is to determine whether the presence of the varicella-zoster virus (VZV) antigens could be used to differentiate the zosteriform LP from the linear LP. METHODS: We immunohistochemically investigated the presence of in vivo localization of VZV antigens in 8 LP lesions (zosteriform LP: n = 5, linear LP: n = 3). RESULTS: We describe 2 cases of zosteriform LP without apparent prior episodes of herpes zoster, in whom VZV antigens were detected in the eccrine epithelium. Further analysis showed that VZV antigens were exclusively detected in the eccrine epithelium in the zosteriform LP lesions, but not in the linear LP lesions. CONCLUSION: Etiological differences exist between zosteriform LP and linear LP. The presence of VZV antigens in lesional skin of the former indicates a possible triggering role of this virus in the pathogenesis of this variant.

Varicella-zoster virus antigen expression of eccrine gland and duct epithelium in herpes zoster lesions.

BACKGROUND: It is well known that varicella-zoster virus (VZV) exhibits tropism for the epidermis and follicular epithelium, while little attention has been paid to eccrine gland and duct involvement by VZV. The presence of herpetic syringitis in immunocompromised hosts suggested the possibility of eccrine gland and duct involvement by VZV. OBJECTIVES: To determine whether VZV antigens could be detected in eccrine gland or duct epithelium of herpes zoster (HZ) lesions obtained at various intervals after the onset of a rash, and whether this expression could also be detected in eccrine units from other inflammatory disease lesions suggestive of VZV infection. METHODS: We investigated immunohistochemically in vivo localization of VZV glycoprotein E (gE) antigen in HZ lesions and control inflammatory disease lesions, using the murine monoclonal antibody directed against the VZV gE. RESULTS: VZV gE was differentially detected in the epidermis, follicular and eccrine epithelium, and dermal infiltrating cells in HZ lesions obtained at various intervals after onset. The VZV gE was most persistently detected in eccrine units, regardless of the age of individual HZ lesions, compared with keratinocytes and follicular epithelium. the ge expression was also observed in other inflammatory disease lesions suggestive of vzv infection. CONCLUSIONS: Immunohistochemical detection of VZV gE in eccrine epithelium can be a subtle clue to the diagnosis of HZ which displays most unusual manifestations, and VZV-related disorders.

Nodular herpes zoster with herpetic syringitis and no epidermal involvement in a patient with Burkitt lymphoma.

Herpes zoster (HZ) occurs with an increased incidence in immunosuppressed patients, in whom it frequently displays atypical clinical presentations. Herpetic syringitis, the involvement of the eccrine epithelium by herpes virus infection, is an infrequently described histologic pattern that has been rarely and almost exclusively reported in HIV-infected patients. We report the case of a woman with Burkitt lymphoma who developed 2 nodular, asymptomatic lesions while receiving treatment with chemotherapy and radiotherapy for her hematological disease. Histology showed viropathic changes in the epithelium of eccrine glands not in the epidermis. PCR was positive for varicella-zoster virus (VZV). Nodular herpes zoster seems to be an exceptional clinical presentation. We report another such case which is, as far as we know, the first report of herpetic syringitis with no concomitant epidermal involvement.

Eccrine-centred distribution of human papillomavirus 63 infection in the epidermis of the plantar skin.

BACKGROUND: The primary target cell of human papillomaviruses (HPVs) is an unsettled issue. Recent studies have suggested that the hair follicle is an important candidate as the reservoir of certain HPV types. However, little is known about the cells which serve as the target or the reservoir of HPVs in nonhairy palmoplantar skin. OBJECTIVES: To investigate whether the eccrine sweat gland, the only skin appendage in nonhairy palmoplantar skin, also serves as the target or the reservoir of HPVs. METHODS: HPV 63-induced warts were employed in this study, because the virus induces tiny warty lesions of a punctuate appearance in the plantar skin and shows peculiar intracytoplasmic inclusion bodies as a diagnostic histopathological marker of infection: this seemed to provide a useful model for the present study. Serial sections were obtained from the entire body of each biopsy specimen and were investigated histologically, immunohistochemically and using DNA-DNA in situ hybridization (ISH) for the histological localization of HPV 63 infection. RESULTS: On microscopy, HPV 63 histopathological changes were seen closely associated with eccrine ducts. Using ISH, HPV 63 DNA was detected not only in keratinocytes resident around acrosyringia but also in the uppermost portion of the eccrine dermal duct. A few keratinocytes harbouring HPV 63 DNA were also identified in acrosyringeal areas in the normal plantar skin adjacent to the wart lesions. CONCLUSIONS: On the basis of our results, it seems likely that HPV 63 targets keratinocytes resident in or around the eccrine ducts in the plantar skin. The results may also suggest that not only hair follicles but also eccrine ducts serve as reservoirs for certain HPV types, including HPV 63, especially in the nonhairy plantar skin.

Cytomegalovirus-induced syringosquamous metaplasia.

An unusual case of syringosquamous metaplasia of the eccrine ducts caused by cytomegalovirus (CMV) is presented. The patient was HIV positive and had extensive excoriation of the perineum and vulva. Biopsy revealed the presence of herpes simplex virus (HSV) inclusions in the necrotic exudate, a CMV vasculitis and extensive involvement of the eccrine ducts. In addition to containing typical CMV inclusions, the eccrine ducts showed proliferation and squamous metaplasia. Inclusions of HSV were not seen within the eccrine ducts by light microscopy or immunohistochemistry. The extensive proliferation with accompanying squamous metaplasia superficially can resemble an infiltrating squamous carcinoma, but this was not evident to a great extent in this case. To the best of our knowledge, our case represents the first of syringosquamous metaplasia of eccrine ducts caused by CMV infection.

Human T-cell lymphotropic virus type I infects eccrine sweat gland epithelia.

Human T-cell lymphotropic virus type I (HTLV-I) is known to be associated with several non-neoplastic inflammatory disorders such as HTLV-I-associated myelopathy/tropical spastic paraparesis, arthropathy, uveitis and lymphadenitis, in addition to neoplastic adult T-cell leukemia/lymphoma (ATLL). A strong relation between HTLV-I infection and Sjögren's syndrome (SS) has been reported, and impaired sweating in SS is well known. We have often encountered dry skin in patients with ATLL. On the basis of these observations, we aimed to determine whether HTLV-I infection is present in isolated sweat glands. Eccrine gland epithelia were isolated from full thickness skin biopsies from 8 HTLV-I-seropositive and 7 seronegative individuals using dispase in Eagle's minimum essential medium supplemented with 13% fetal calf serum. We detected HTLV-IpX sequences in samples of eccrine sweat gland epithelia from 4 samples of the 8 seropositive individuals using nested polymerase chain reaction, but all 7 samples from the seronegative donors had no signal corresponding to the sequence. Our results were confirmed by dot blot hybridization. Our results suggest that eccrine epithelium is one of the target organs of HTLV-I infection.

Measles virus was present in the inner cell of the acrosyringium in the skin rash.

A case of measles in a 26-year-old Japanese man is reported. A skin specimen taken on the third eruptive day from a maculopapular eruption on his chest was immunohistopathologically and electron microscopically examined using a rabbit polyclonal antibody against the nucleocapsid protein of the measles virus. The measles virus antigen was found in the inner cells of the acrosyringium and hair follicles. The measles virus nucleocapsid was electron microscopically identified in the nuclei of the inner cells of the acrosyringium. The findings suggest that the sweat from skin lesions might contain the measles virus.

Herpetic syringitis associated with eccrine squamous syringometaplasia in HIV-positive patients.

Herpetic syringitis has been described as a rare manifestation of herpes virus infection in patients with an immunodeficiency, usually secondary to human immunodeficiency virus (HIV) infection. Eccrine squamous syringometaplasia (ESS) is an infrequent alteration of the eccrine duct epithelium reported in association with several conditions, including chronic ulcers, inflammatory processes, and patients receiving chemotherapy. The association of herpetic syringitis with ESS has not been reported before. We identified 3 cases of herpetic syringitis associated with ESS in patients with the acquired immunodeficiency syndrome. In 2 of 3 cases the signs of herpetic syringitis were limited to the metaplastic duct epithelium, but in 1 case there were also herpetic alterations without ESS. The histological features of herpetic infection in HIV-positive patients may be atypical and lack the typical epidermal alterations, observing only an extensive epidermal necrosis. In those cases, the alterations of the eccrine ducts may be a diagnostic clue in the diagnosis of herpetic infection. ESS of the ductal epithelium is probably secondary to the herpetic infection, although it might also stimulate the extension of the herpetic infection. Further studies are needed to elucidate the association of ESS and herpes virus infection.

Subtle clues to the diagnosis of the herpesvirus by light microscopy. Herpetic syringitis.

Among the numerous infections to which AIDS patients are susceptible, those caused by herpesvirus (simplex and varicella/zoster) are among the most common. Because herpetic infections may be the first manifestations of AIDS and often are associated with poor prognosis, rapid and accurate diagnosis of them is imperative. Herpesvirus infection may be diagnosed histopathologically by the presence of ballooned, acantholytic, and multinucleated keratinocytes; intranuclear eosinophilic viral inclusions; steel gray color of affected keratinocytic cytoplasm and nuclei, chromatin margination, and necrotic acantholytic keratinocytes in older lesions. These changes are often limited to the epidermis, but there may frequently be involvement of epithelia of follicles (herpetic folliculitis) and sebaceous glands as well. Similar changes, although seldom noted, may be present in eccrine ducts and glands (herpetic syringitis). Recognition of subtle histologic clues concerning the secretory and ductal components of sweat glands in an unusual case of herpes infection facilitated rapid diagnosis in an AIDS patient, allowing appropriate treatment.