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At least 19 recordsLinked to original sources
PubMed2001

Winter grazing of reindeer in woodland lichen pasture. Effect of lichen availability on the condition of reindeer.

Winter grazing of semi-domesticated reindeer (Rangifer t. tarandus) was investigated at the woodland lichen pasture (lichen approximately 550kg DMha(-1)) in Kaamanen, northern Finland during the winter 1996-1997. Nine female reindeer mainly dug their food in the snow for 122 days (3 December-4 April) in a fenced area of 36.3ha. Over half of the fenced area was lichen dominated dry pine forest. The amount of lichens in lichen forest inside the fence was estimated before and after grazing. Area of grazed and condition of reindeer as well as snow conditions were monitored. Reindeer grazed over the whole area of lichen forest in early winter but from mid-winter they tended to graze on the areas with the greatest lichen abundancy. The amount of lichens measured decreased in the latter areas by 40% and in the other part of the lichen pasture by 17%, respectively. In both of these areas the residual amounts of lichens left after grazing were similar. Of the dominant lichens, the amount of C. stellaris decreased the most and the amount of Cl. uncialis the least. During the study, the estimated average daily area grazed varied from 4 to 87m(2) per reindeer. It was calculated that individual reindeer obtained 2.6kg of lichen DM per day during the most intensive digging period when the body condition score and weight of reindeer increased. Otherwise, the body condition score and weight decreased. Reindeer finished foraging for ground lichens and started to search for arboreal lichens in mid-March when the snow layer was 70-80cm thick and contained some hard snow layers which lifted reindeer. Both the amount of lichens in the pasture and the snow conditions essentially affect the nutritional status of reindeer in the woodland region during winter. Assuming that a reindeer is able to graze around 30m(2) per day in the snow during mid and late winter, there should be, on the basis of energy demand and grazing behaviour of reindeer as well as the nutritive value of lichen, an estimated 1000kg lichen DMha(-1) available in a good condition woodland lichen pasture.

Journal Article↗
PubMed1989

Bullous lichen planus and lichen planus pemphigoides--clinico-pathological comparisons.

Two patients with lichen planus pemphigoides and two with bullous lichen planus were compared. Lichen planus pemphigoides was clinically distinguished by a more generalized lichen planus, more extensive blistering, the need for systemic corticosteroids and by a longer course. The blister of bullous lichen planus was a subepidermal bulla showing degeneration of the epidermal basal layer and other features of lichen planus, whereas in lichen planus pemphigoides the bulla was similar to that of bullous pemphigoid albeit with rather more neutrophils than are usually seen. Direct immunofluorescence was positive in lichen planus pemphigoides and negative in bullous lichen planus. Lichen planus pemphigoides and bullous lichen planus are separate entities: the former is an auto-immune disease precipitated by lichen planus and not related to bullous pemphigoid, the latter is probably not auto-immune but represents the extreme consequence of the lymphoid infiltrate at the dermo-epidermal junction.

Adult↗
PubMed2003

Analysis of hepatitis C virus (HCV) RNA in the lesions of lichen planus in patients with chronic hepatitis C: detection of anti-genomic- as well as genomic-strand HCV RNAs in lichen planus lesions.

BACKGROUND: Hepatitis C virus (HCV) is a single-strand RNA virus. The association of lichen planus with chronic HCV infection has been reported, as has been cryoglobulinemic purpura, psoriasis, urticaria, and porphyria cutanea tarda. However, the cause of lichen planus is unclear. OBJECTIVES: To investigate whether genomic- and/or anti-genomic-strand HCV RNAs are present in the lichen planus lesions of chronic hepatitis C patients and to elucidate the pathogenesis of lichen planus. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) followed by nested-PCR was carried out to detect HCV RNA using RNA samples from lichen planus lesions of three patients with chronic hepatitis C. Since it is well known that commonly there is relatively dense inflammatory cell infiltration mainly in the upper dermis in lichen planus, the same RT-PCR procedure was performed using RNA from peripheral blood leukocytes from the same patients. In addition, in one patient, the same procedure was also performed using an RNA sample from normal skin. RESULTS: Bands of the appropriate size (161 base pairs corresponding to region 98-258 of HCV RNA) in the nested-PCR products for both genomic- and anti-genomic-strands were detected in lichen planus lesions as well as in peripheral blood leukocytes in all the cases. CONCLUSION: To the best of our knowledge, this is the first report showing the presence of anti-genomic- as well as genomic-strand HCV RNAs in lichen planus lesions in patients with chronic hepatitis C; suggesting that HCV-associated lichen planus lesions may be sites of HCV replication.

Female↗
PubMed1999

Does lichen sclerosus play a central role in the pathogenesis of human papillomavirus negative vulvar squamous cell carcinoma? The itch-scratch-lichen sclerosus hypothesis.

In the past decade, two types of vulvar squamous cell carcinoma (SCC) have been delineated, Human papillomavirus (HPV) positive and negative. Clinicopathologic, virologic, cytomorphometric, and genetic differences support the view that these two types of carcinoma are fundamentally different and that HPV-negative carcinoma is not simply carcinoma where viral DNA has not been able to be identified. The traditional view of HPV-negative carcinoma is that it is caused by chronic tissue damage from itching and scratching. However, itching and scratching alone do not explain the close association of carcinoma with lichen sclerosus, nor the absence of such an association with other itchy conditions such as eczema or psoriasis. These observations point to a role for lichen sclerosus in the pathogenesis of vulvar carcinoma. Most observations about the etiology of lichen sclerosus can be grouped into its immunogenetic or genital predisposition, or the Köbner phenomenon. In the itch-scratch-lichen sclerosus hypothesis, lichen sclerosus is postulated to occur as a Köbner phenomenon in women with the susceptible immunophenotype who scratch because of genital irritants such as urine, vaginal secretions and smegma, and psychological factors. Lichen sclerosus, itself a very itchy condition, contributes to a vicious cycle of itching and scratching which leads to superimposed lichen simplex chronicus, squamous cell hyperplasia, and ultimately carcinoma. The itch-scratch-lichen sclerosus hypothesis reconciles the traditional itch-scratch hypothesis with the strong clinicopathologic association of lichen sclerosus with carcinoma.

Journal Article↗
PubMed1995

Generalized lichen nitidus appearing subsequent to lichen planus.

A 27-year-old man was seen with multiple, small, shiny papules on his shoulders, upper arms, and trunk, and hyperpigmented violaceous plaques on his feet. The former was diagnosed as generalized lichen nitidus and the latter, as lichen planus. It is not likely that the coexistence of the two diseases in this patient is a fortuitous one, since generalized lichen nitidus is a very rare condition. The association of lichen nitidus and lichen planus suggests that lichen nitidus is closely related to lichen planus and that the two diseases may be different manifestations of essentially the same pathogenetic process.

Adult↗
PubMed1986

Toxicity of Iceland lichen and reindeer lichen.

Iceland lichen (Cetraria islandica) is sold in health food stores to prevent various disorders. In olden times it and sometimes also reindeer lichen (Cladonia sp.) have been used as emergency food. Lichen contains bitter and potentially toxic lichen acids and it also concentrates heavy metals. Therefore lichen toxicity was studied with traditional pretreatment methods (boiling, ash-soaking or both). Untreated and only shortly boiled lichens were lethally toxic to mice in 50 and 25% w/w mixtures in food, but when ash-soaking was added mice tolerated Cetraria (but not Cladonia) reasonably well for 3 weeks. In a 3 month test in rats 25% mixture of Cladonia was tolerated well and blood tests were normal at the end. However, urinary protein was increased, the autopsies revealed kidney changes corresponding to a mild heavy metal poisoning, as the lead concentrations in kidney and lichen were high.

Animals↗
PubMed2003

Non-destructive analysis of pigments and other organic compounds in lichens using Fourier-transform Raman spectroscopy: a study of Antarctic epilithic lichens.

Lichens in Antarctic habitats are subjected to environmental extremes, including UVB radiation, desiccation and low temperatures, as well as to rapid fluctuations in these. Lichens synthesise a variety of chemical compounds in response to their environmental conditions which contribute towards their colour, and which act as protectants against physiological stresses. The fluorescence generated by the lichens at 532 nm can be used in epifluorescence microscopy to identify their presence on substrata but this can severely affect the Raman spectra using visible excitation. The advantage of the near infrared excitation used in FT-Raman spectroscopy in minimising fluorescence emission facilitates the molecular characterisation of lichen encrustations without having to remove the thallus from its substrate or remove or otherwise damage any part of the thallus. Spectroscopic biomarkers are proposed which allow the lichens to be characterised by the identification of characteristic lichen substances; the use of these biomarkers for the preliminary taxonomic identification of Antarctic lichens is examined and some potential pitfalls are described.

Antarctic Regions↗
PubMed2000

Lichen planus--specific antigen in oral lichen planus and oral lichenoid drug eruptions.

OBJECTIVE: To investigate the usefulness of lichen planus-specific antigen as a marker to distinguish idiopathic oral lichen planus from oral lichenoid drug eruptions. STUDY DESIGN: Biopsy samples were taken from 6 patients with oral lichenoid drug eruptions and 6 patients with idiopathic oral lichen planus. Each biopsy sample was examined for the presence of lichen planus-specific antigen by using a modification of a previously described immunofluorescence method that uses autologous serum and also allogenic sera from the remaining 11 cases. RESULTS: All autologous and allogenic immunofluorescence tests showed negative findings for lichen planus-specific antigen. CONCLUSIONS: Lichen planus-specific antigen is not a useful marker to distinguish oral lichenoid drug eruptions from idiopathic lichen planus. This finding is in contrast with our findings in an earlier study of basal cell cytoplasmic autoantibodies.

Antigens↗
PubMed1983

Lichen planus dermopathy: demonstration of a lichen planus specific epidermal antigen in affected patients.

Lichen planus is a common papulosquamous disorder of skin and mucous membranes of unknown etiology. Studies reported here demonstrate a lichen planus specific antigen (LPSA) in granular and deep prickle epithelial cells from the lichen planus lesion. Sera from seven out of eight lichen planus patients tested contained an antibody to LPSA. The LPSA was not detected in normal skin tissues from lichen planus patients, or in skin from normal donors and skin from patients with skin disorders other than lichen planus. A serologic survey of serum from people with no clinical history of lichen planus revealed approximately a 7% incidence of antibody to LPSA. These studies suggest that LPSA may be of exogenous origin.

Adolescent↗
PubMed1998

Lichen sclerosus and lichen planus: a spectrum of disease? Report of two cases and review of the literature.

There has long been controversy concerning the relationship between lichen planus and lichen sclerosus. Whilst these two conditions are now considered distinct, there are shared clinical and pathological features. We now describe two patients with the cutaneous involvement of both lichen planus and lichen sclerosus, presenting a review of similar reported cases and discussing the implications for pathogenesis of these two diseases. Neither lichen planus (LP) nor lichen sclerosus (LS) are uncommon yet they have only infrequently been reported as coexisting. In his original description of LS, however, Hallopeau considered it to be a variant of LP and Gougerot has also commented on a possible common pathogenesis for the two conditions. Features which tend to support such as association include the distribution of the cutaneous lesions, histopathological features such as hydropic basal cell degeneration and a band-like lymphohistiocytic infiltrate in the dermis, and the reported association with autoimmune disease. We now report two patients in whom coexistent cutaneous LS and LP was confirmed histologically.

Adult↗
PubMed1992

Immunohistochemical examination of lichen nitidus suggests that it is not a localized papular variant of lichen planus.

BACKGROUND: Lichen nitidus is believed, by some, to be a variant of lichen planus, and by others to be a distinct entity. OBJECTIVE: We examined five cases of lichen nitidus with immunohistochemical reagents designed to characterize the dermal inflammatory infiltrate in an attempt to resolve the uncertainty. METHODS: We stained formalin-fixed, paraffin-embedded tissue sections with the following antibodies: L26, A6, KP1, BerH2, OPD4, and HECA-452. RESULTS: The inflammatory infiltrate was 90% A6+, with few L26+ cells. In contrast to lichen planus, KP1+ macrophages were seen and fewer of the lymphocytes demonstrated HECA-452. Fifty percent to 80% of lymphocytes were OPD4 positive, similar to that usually seen in lichen planus. Rare Ki-1+ cells were seen in one case. CONCLUSION: We believe that the pattern of a mixed cellular infiltrate characterized by macrophages and a helper T cell response with few HECA-452+ cells is somewhat different from the pattern seen in lichen planus, wherein almost all of the cells are CD4+/HECA-452+ lymphocytes. This suggests a different immunologic pathogenesis.

Dermatitis↗
PubMed2001

Hepatitis C virus infection prevalence in lichen planus: examination of lesional and normal skin of hepatitis C virus-infected patients with lichen planus for the presence of hepatitis C virus RNA.

Hepatitis C virus (HCV) is the main cause of parenterally transmitted non-A, non-B viral hepatitis. In recent years, a significant association between lichen planus and chronic HCV infection has been reported. Anti-HCV antibody status was evaluated by ELISA in 54 patients with lichen planus and 54 patients with minor dermatological disorders. PCR was used to examine HCV RNA from serum and lesional and nonlesional cutaneous biopsy samples of HCV-infected patients. Seven patients with lichen planus (12.9%) and two patients in the control group (3.7%) were anti-HCV antibody positive. Five out of seven patients with anti-HCV antibodies had demonstrable HCV RNA in lesional skin biopsies. The viral RNA was absent in three out of four patients with lichen planus whose serum samples were positive for HCV RNA and agreed to biopsy of nonlesional skin. The prevalence of HCV infection is not increased in Turkish patients with lichen planus. However our findings suggest that the virus may play a potential pathogenic role by replicating in cutaneous tissue and triggering lichen planus in genetically susceptible HCV-infected patients.

Adolescent↗
PubMed1965

Allergy to lichens. Allergic contact dermatitis from usnic acid produced by lichenized fungi.

Two forest workers affected with allergic contact dermatitis, which occurred only during work in forest areas, showed positive patch test reactions to lichens containing usnic acid and to isolated usnic acid. Lichens are plants composed of fungi living in symbiosis with algae. Usnic acid, one of the lichenic acids which accumulates in lichenized fungi, is a monobasic acid with dibenzofuran structure and antibiotic properties. Dibenzofuran is chemically related to furocoumarans. Lichens are plentiful in temperate zone forests and allergy to usnic acid represents some part of the "cedar-poisoning" problem in British Columbia. Geographical distribution of lichens containing usnic acid suggests that allergy to usnic acid will be found to be more common than presently recognized.

Adult↗
PubMed1998

Treatment of lichen planus and lichen nitidus with itraconazole: reports of six cases.

Six patients with either lichen planus or lichen nitidus were treated with itraconazole. Two of four patients with lichen planus experienced complete clearing, and the remainder showed a partial response. Itraconazole, like griseofulvin, may prove to be an alternative treatment worth considering in patients with lichen planus or lichen nitidus who have failed other therapies.

Adult↗
PubMed2000

The distribution of group I introns in lichen algae suggests that lichenization facilitates intron lateral transfer.

The nuclear-encoded small subunit ribosomal DNA gene of many lichen-forming green algae in the genus Trebouxia contains a group I intron at Escherichia coli genic position 1512. We studied the evolutionary history of the 1512 intron in Trebouxia spp. (Trebouxiophyceae) by analyzing intron and "host" cell phylogenies. The host trees were constructed by comparing internal transcribed spacer regions of rDNA. Maximum-likelihood, maximum-parsimony, and distance analyses suggest that the 1512 intron was present in the common ancestor of the green algal classes Trebouxiophyceae, Chlorophyceae, and Ulvophyceae. The 1512 intron, however, was laterally transferred at least three times among later-diverging Trebouxia spp. that form lichen partnerships. Intron secondary structure analyses are consistent with this result. Our results support the hypothesis that lichenization may facilitate 1512 group I intron lateral transfer through the close cell-to-cell contact that occurs between the lichen algal and fungal symbionts in the developing lichen thallus.

Alternative Splicing↗
PubMed1986

Lichen planus and coexisting lupus erythematosus versus lichen planus-like lupus erythematosus. Clinical, histologic, and immunopathologic considerations.

A middle-aged black woman presented initially with painful cutaneous plaques that were located at various sites and that were diagnosed histologically as lichen planus. Standard light microscopic examination showed histopathologic variants of lichen planus. Direct immunofluorescence of a skin lesion had negative results for any of the lupus erythematosus bands but did reveal hyaline bodies in the deep cellular layer of the epidermis and the superficial layer of the dermis. These findings were compatible with either lichen planus or lupus erythematosus. However, both the clinical course of the eruption and the antinuclear antibody tests showed that the immunofluorescent antinuclear antibody pattern of large, speckle-like threads were consistent with lupus erythematosus. Furthermore, the large, speckle-like, thready antinuclear antibody pattern, which has been shown to be a marker for a benign subset of lupus erythematosus, is not seen in lichen planus. Lichen planus--like lupus erythematosus was therefore the more likely diagnosis.

Antibodies, Antinuclear↗
PubMed1977

[Coexistence of lichen planus and bullous pemphigoid (an immunofluorescence study of a "lichen pemphigoides") (author's transl)].

A 35 year old black man presented with a generalized eruption of lichen planus; subsequently tense blisters appeared within the lichenoid lesions and on clinically normal skin. Histopathological characteristics of lichen planus were present in the papules, and those of bullous pemphigoid were seen in the bullae taken from non-lichenoid skin. Direct immunofluorescence studies revealed immunological characteristics of lichen planus in skin and mucosal lesions of L. P. Bound IgG and beta1 C/beta1 A with tubular patterns were detected at the dermo-epidermal junction in all the skin fragments (clinically normal skin, bullous lesions lichenoid skin and mucous lesions). Indirect immunofluorescence studies showed at several intervals that the patient had circulating antibasement membrane zone antibodies (IgG; titres 1/50). This is the third published case in which immunofluorescence studies have established the "pemphigoid" nature of some bullous lichen planus. These findings are in favour of an immune disorder in lichen planus.

Adult↗