Pityriasis rosea is associated with systemic active infection with both human herpesvirus-7 and human herpesvirus-6.
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Pityriasis rosea is a common skin disease that has been suspected to have a viral etiology. We performed nested polymerase chain reaction to detect human herpesvirus-7, human herpesvirus-6, and cytomegalovirus DNA in lesional skin, nonlesional skin, peripheral blood mononuclear cells, serum, and saliva samples isolated from 14 pityriasis rosea patients. Viral mRNA expression and virion visualization within lesional skin were studied by in situ hybridization and transmission electron microscopy, respectively. By nested polymerase chain reaction, human herpesvirus-7 DNA was present in lesional skin (93%), nonlesional skin (86%), saliva (100%), peripheral blood mononuclear cells (83%), and serum (100%) samples, whereas human herpesvirus-6 DNA was detected in lesional skin (86%), nonlesional skin (79%), saliva (80%), peripheral blood mononuclear cells (83%), and serum (88%) samples. By contrast, cytomegalovirus DNA was not detected in these tissues. Control samples from 12 healthy volunteers and 10 psoriasis patients demonstrated rare positivity for either human herpesvirus-7 or human herpesvirus-6 DNA in skin or serum. By in situ hybridization, infiltrating mononuclear cells expressing human herpesvirus-7 and human herpesvirus-6 mRNA were identified in perivascular and periappendageal areas in 100% and 75% pityriasis rosea skin lesions, respectively, compared to herpesviral mRNA positivity in only 13% normal skin and psoriasis skin controls. Transmission electron microscopy failed to reveal herpesviral virions in pityriasis rosea lesional skin. Nested polymerase chain reaction and in situ hybridization enabled detection of human herpesvirus-7 and human herpesvirus-6 in skin and other tissues isolated from patients with pityriasis rosea. These results suggest that pityriasis rosea is associated with systemic active infection with both human herpesvirus-7 and human herpesvirus-6. (+info)
Viral exanthems.
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Viral exanthems are mostly associated with self-limited diseases. However, in some cases diagnosis of an exanthem may be crucial to patients and their contacts. Certain exanthems have fairly characteristic morphology, but in many cases an accurate diagnosis cannot be made on the basis of morphology alone. Historical factors may be helpful when evaluating these patients, specifically their disease contacts, immunization record, previous exanthematous illnesses, and associated prodromal symptoms. Some illnesses are seasonal and this knowledge may be useful. This manuscript reviews a number of common childhood exanthems. We included the most common viral exanthems encountered by primary-care physicians and dermatologists. (+info)
Pityriasis rosea.
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Pityriasis rosea is a common, acute exanthem of uncertain etiology. Viral and bacterial causes have been sought, but convincing answers have not yet been found. Pityriasis rosea typically affects children and young adults. It is characterized by an initial herald patch, followed by the development of a diffuse papulosquamous rash. The herald patch often is misdiagnosed as eczema. Pityriasis rosea is difficult to identify until the appearance of characteristic smaller secondary lesions that follow Langer's lines (cleavage lines). Several medications can cause a rash similar to pityriasis rosea, and several diseases, including secondary syphilis, are included in the differential diagnosis. One small controlled trial reported faster clearing of the exanthem with the use of erythromycin, but the mechanism of effect is unknown. Resolution of the rash may be hastened by ultraviolet light therapy but not without the risk of hyperpigmentation. Topical or systemic steroids and antihistamines often are used to relieve itching. (+info)
Pityriasis rosea--evidence for and against an infectious aetiology.
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Pityriasis rosea, first named as such in 1860, probably holds the longest record for an exanthem suspected to be associated with an infection but for which an exact cause has not been found. The distinctly programmed clinical course, the lack of recurrence for most patients, and the presence of temporal case clustering provide the strongest evidence to support an infectious aetiology. Further support comes from seasonal variation and the association with respiratory tract infections, the unfavourable social and economic background of cases, and a history in some cases of contact with patients with pityriasis rosea. The apparent therapeutic efficacy of several treatment modalities does not provide strong evidence for or against an infectious aetiology. The roles of human herpesvirus 7 and to a lesser extent human herpesvirus 6 remain controversial. There exists reasonable evidence that pityriasis rosea is not associated with cytomegalovirus, Epstein-Barr virus, parvovirus B19, picornavirus, influenza and parainfluenza viruses, Legionella spp., Mycoplasma spp. and Chlamydia spp. infections. Evidence is also unsubstantiated as yet for alternative aetiological hypotheses such as autoimmunity, atopy, and genetic predisposition. (+info)
Clinical and histopathological findings in pustular psoriaform dermatitis (pityriasis rosea) in pigs.
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Three cases of pustular psoriaform dermatitis (pityriasis rosea) in pigs were clinically and histopathologically examined. Grossly, the affected skin was characterized by multiple, circumscribed lesions. Three pigs were the descendants derived from the same Landrace boar. Skin lesions expanded centrifugally to became ring-shaped plaques. There were no abnormal values in hematological and serum biochemical profiles. Histopathologically, the epidermis showed remarkable thickening. The dermal lesions were characterized by a prominent component of superficial and deep perivascular infiltration of eosinophils. Dilatation of microvasculature was accompanied with congested vessels. These results revealed that the etiology of pustular psoriaform dermatitis in pigs was associated with a hereditary predisposition derived from the specific boars. This dermatosis is histopathologically characterized by microcirculatory disturbances with infiltration of abundant eosinophils. (+info)
Pityriasis rosea with palmoplantar plaque lesions.
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Pityriasis rosea is a skin disease characterized by sharply defined pruritic red patches covered by fine scales. It affects mostly adolescent and young adults. Typical lesions usually affect the trunk in a Christmas-tree pattern. The eruption usually resolves after 6 weeks but symptomatic treatment may be needed. Two patients are reported with classic presentation of pityriasis rosea except for the unusual associated palmoplantar lesions; both patients had negative RPR (with dilutions) and MHA-TP. They responded to 2-week courses of either oral erythromycin or Clarithromycin with complete resolution. (+info)
Additional evidence that pityriasis rosea is associated with reactivation of human herpesvirus-6 and -7.
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To elucidate the role of human herpesvirus (HHV)-6 and -7 (HHV-7) in pityriasis rosea (PR), we measured their DNA load in plasma, peripheral blood mononuclear cells (PBMC), and tissues using a calibrated quantitative real-time PCR assay. We also studied HHV-6- and HHV-7-specific antigens in skin by immunohistochemistry and anti-HHV-7 neutralizing activity using a syncytia-inhibition test. Plasma and PBMC were obtained from 31 PR patients (14 children, 17 adults), 12 patients with other dermatites, and 36 blood donors. Skin biopsies were obtained from 15 adults with PR and 12 with other dermatites. HHV-6 and HHV-7 DNA were detected in 17% and in 39% of PR plasmas, respectively, but in no controls. HHV-7 viremia was associated with a higher PBMC load and, in adults, with systemic symptoms. HHV-7, but not HHV-6, levels in PBMC were higher in PR patients than in controls. HHV-6 and HHV-7 antigens were found only in PR skin (17% and 67% of patients analyzed, respectively), indicating a productive infection. Syncytia-neutralizing antibodies were found in PR patients and controls, but their titers were lower in patients with HHV-7 viremia. These data confirm the causal association between PR and active HHV-7 or, to a lesser extent, HHV-6 infection. (+info)
Pityriasis rosea-like eruptions due to mustard oil application.
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A young man employed in a construction company, presented with cutaneous lesions clinically simulating pityriasis rosea. Satisfactory and complete response to corticosteroids and antihistamines was followed by recurrence. Multiple recurrences within a short span of time arose a suspicion of alternative diagnosis. Site visit helped us to rule out occupational contact dermatitis. Further history taking revealed that he was recently using mustard oil for body massage. Subsequent patch testing confirmed contact hypersensitivity to mustard oil. Avoidance of the contact with mustard oil arrested appearance of further skin lesions. We stress the importance of taking a good history in clinical practice in disclosing a possible contactant. (+info)